Literature Supporting Claims Regarding the Environmental ... · green adaptations for urban development in Dhaka, Bangladesh." Landscape and Urban Planning 173: 23-32. We evaluated

Literature Supporting Claims Regarding

the Environmental Benefits of Plants

Listed in chronological order

Zinia, N. J. and P. McShane (2018). "Ecosystem services management: An evaluation of

green adaptations for urban development in Dhaka, Bangladesh." Landscape and Urban

Planning 173: 23-32.

We evaluated green adaptation strategies (parks, gardens, green roof, rainwater harvest,

green façades/wall, porous pavement, and green and blue belts) in the context of urban

development and potential climate change impacts for the city of Dhaka, Bangladesh. Our

review of relevant literature revealed substantial environmental (cooler and cleaner

environment), economic (reduced energy demand, avoided cost of drainage maintenance,

increased land values) and social (higher social interaction, improved mental and physical

health) benefits arising from the maintenance and development of ecosystem services in major

cities. Our evaluation of green adaptation strategies was undertaken with household surveys in

three wards of Dhaka, expert interviews, and our personal experiences. Rooftop

gardens/agriculture had very high social acceptance (85%) and economic feasibility and was

commonly practiced in Dhaka, particularly among house owners. Pocket park, green roof,

rainwater harvest, green façades/wall, porous pavement, and community garden were all

considered to be highly feasible for implementation with collective efforts but had lower social

acceptance. Many respondents were unwilling to pay for green adaptation strategies even

knowing their benefits. Our research revealed that successful implementation of beneficial green

adaptation will require public participation at all stages supported through awareness raising

campaigns. Enforcement of laws and strong commitment from the government was also

considered to be beneficial. However, more transparent cost-benefit analyses promoting the

conservation of ecosystem services is required, particularly for resource-poor Dhaka. Green

adaptations make cities more resilient to pressures from demographic change and climate change

increasingly relevant in the developing world.

Simon, H., et al. (2018). "Modeling transpiration and leaf temperature of urban trees–A

case study evaluating the microclimate model ENVI-met against measurement data."

Landscape and Urban Planning 174: 33-40.

Increasing vegetation cover in cities is a key approach to mitigating urban heat excess.

However, both the effect of vegetation on microclimate and the plants’ vitality need to be

assessed to support and quantify the effects of such strategies. One way to assess the interactions

between vegetation and the urban environment is through microclimate models that can simulate

the effects of vegetation onto the urban microclimate as well as effects of urban environments

onto vegetation. To provide reliable estimates microclimate models need to be parameterized

based on empirically obtained data. In this paper we compare modeled transpiration rates and

leaf temperatures of a leading microclimate model, ENVI-met V4, with in-situ measured stem

sap flow and leaf temperatures of two different trees in an urban courtyard. The vegetation model

of ENVI-met is evaluated considering four synoptic situations including varying cloud covers

ranging from fully cloudy to clear sky. The comparison of simulation results with empirical data

reveals a high agreement. The model is capable of capturing the magnitude as well as short-term

variations in transpiration caused by microclimatic changes. However, substantial deviations

were found in situations with low photosynthetic active radiation. Modeled and observed diurnal

tree transpiration and leaf temperature showed good agreement. These findings indicate that

ENVI-met is capable of simulating transpiration rates and leaf temperatures of trees in complex

urban environments.

Tigges, J., et al. (2017). "Modeling above-ground carbon storage: a remote sensing

approach to derive individual tree species information in urban settings." Urban

Ecosystems 20(1): 97-111.

Vegetation has gained importance in respective debates about climate change mitigation

and adaptation in cities. Although recently developed remote sensing techniques provide

necessary city-wide information, a sufficient and consistent city-wide information of relevant

urban ecosystem services, such as carbon emissions offset, does not exist. This study uses city-

wide, high-resolution, and remotely sensed data to derive individual tree species information and

to estimate the above-ground carbon storage of urban forests in Berlin, Germany. The variance

of tree biomass was estimated using allometric equations that contained different levels of detail

regarding the tree species found in this study of 700 km2, which had a tree canopy of 213 km2.

The average tree density was 65 trees/ha per unit of tree cover and a range from 10 to 40 trees/ha

for densely urban land cover. City-wide estimates of the above-ground carbon storage ranged

between 6.34 and 7.69 tC/ha per unit of land cover, depending on the level of tree species

information used. Equations that did not use individually localized tree species information

undervalued the total amount of urban forest carbon storage by up to 15 %. Equations using a

generalized estimate of dominant tree species information provided rather precise city-wide

carbon estimates. Concerning differences within a densely built area per unit of land cover

approaches using individually localized tree species information prevented underestimation of

mid-range carbon density areas (10–20 tC/ha), which were actually up to 8.4 % higher, and

prevented overestimation of very low carbon density areas (0–5 tC/ha), which were actually up

to 11.4 % lower. Park-like areas showed 10 to 30 tC/ha, whereas land cover of very high carbon

density (40–80 tC/ha) mostly consisted of mixed peri-urban forest stands. Thus, this approach,

which uses widely accessible and remotely sensed data, can help to improve the consistency of

forest carbon estimates in cities.

Threlfall, C. G., et al. (2017). "Increasing biodiversity in urban green spaces through

simple vegetation interventions." Journal of Applied Ecology.

Cities are rapidly expanding world-wide and there is an increasing urgency to protect

urban biodiversity, principally through the provision of suitable habitat, most of which is in

urban green spaces. Despite this, clear guidelines of how to reverse biodiversity loss or increase

it within a given urban green space is lacking.

We examined the taxa- and species-specific responses of five taxonomically and

functionally diverse animal groups to three key attributes of urban green space vegetation that

drive habitat quality and can be manipulated over time: the density of large native trees, volume

of understorey vegetation and percentage of native vegetation.

Using multi-species occupancy-detection models, we found marked differences in the

effect of these vegetation attributes on bats, birds, bees, beetles and bugs. At the taxa-level,

increasing the volume of understorey vegetation and percentage of native vegetation had

uniformly positive effects. We found 30–120% higher occupancy for bats, native birds, beetles

and bugs with an increase in understorey volume from 10% to 30%, and 10–140% higher

occupancy across all native taxa with an increase in the proportion of native vegetation from

10% to 30%. However, increasing the density of large native trees had a mostly neutral effect. At

the species-specific level, the majority of native species responded strongly and positively to

increasing understorey volume and native vegetation, whereas exotic bird species had a neutral

response.

Synthesis and applications. We found the probability of occupancy of most species

examined was substantially reduced in urban green spaces with sparse understorey vegetation

and few native plants. Our findings provide evidence that increasing understorey cover and

native plantings in urban green spaces can improve biodiversity outcomes. Redressing the

dominance of simplified and exotic vegetation present in urban landscapes with an increase in

understorey vegetation volume and percentage of native vegetation will benefit a broad array of

biodiversity.

Park, J., et al. (2017). "The influence of small green space type and structure at the street

level on urban heat island mitigation." Urban Forestry & Urban Greening 21: 203-212.

The purpose of this study was to determine the types and structures of small green spaces

(SGs) that effectively reduce air temperature in urban blocks. Six highly developed blocks in

Seoul, South Korea served as the research sites for this study. Air temperature was measured at

the street level with mobile loggers on clear summer days from August to September in 2012.

The measurements were repeated three times a day for three days. By analyzing the spatial

characteristics, SGs within the six blocks were categorized into the four major types: polygonal,

linear, single, and mixed. The result revealed that the polygonal and mixed types of SGs showed

simple linear regression at a significant level (p < 0.01). It indicated that the blocks’ urban heat

island (UHI) mitigation (ΔTRmn) increased in a linear fashion when the area and volume of

these two types of green spaces increased. The area and volume of a polygonal SG with mixed

vegetation, over 300 m2 and 2300 m3, respectively, lowered the ΔTRmn by 1 °C; SG with an

area and volume of larger than 650 m2 and 5000 m3, respectively, lowered the ΔTRmn by 2 °C.

The results of this study will be useful to urban planners and designers for determine the types

and structures of urban green spaces to optimize the cooling effect, as well as how such green

spaces should be designed and distributed.

Ow, L. F. and S. Ghosh (2017). "Urban cities and road traffic noise: Reduction through

vegetation." Applied Acoustics 120: 15-20.

This study was carried out to determine the effect of roadside vegetation on the reduction

of road traffic noise under varying planting intensities. Roadside vegetation ranging from

minimal planting through to moderate and dense plantings were used. The results showed that

the traffic noise was reduced by 50% when vegetation was enhanced from a minimal to moderate

planting intensity, and no enhancement in noise reduction was observed as vegetation was

further increased to a dense intensity. A 5 m depth of vegetation barrier was found to be an ideal

depth for traffic noise reduction. Without the vegetative barrier, the observed mean noise levels

were 78 dB. On average, vegetative barriers (moderate to dense) were able to reduce traffic noise

by 9–11 dB. Trunk size was found to be linearly related to traffic noise abatement and synthetic

barriers were found to be inferior to tree belts both psychologically and in absolute values of

noise. This report also investigated the effectiveness associated with setbacks where it was found

that the greater the setback distance, the higher the level of noise amelioration and a 10 m depth

was identified as the threshold for an effective tree belt.

Margaritis, E. and J. Kang (2017). "Relationship between green space-related morphology

and noise pollution." Ecological Indicators 72: 921-933.

Green spaces have been proved to have a positive effect on traffic noise pollution in the

local scale; however their effects have not been explored on the urban level. This paper

investigates the effects of green space-related parameters from a land cover viewpoint on traffic

noise pollution in order to understand to what extent greener cities can also be quieter. A triple

level analysis was conducted in the agglomeration, urban and kernel level including various case

study cities across Europe. The green space parameters were calculated based on land cover data

available in a European scale, while traffic noise data were extracted from online noise maps and

configured in noise indices. In the first level 25 agglomerations were investigated, six of which

were further analyzed in the urban and kernel levels. It was found that the effect of green spaces

on traffic noise pollution varies according to the scale of analysis. In the agglomeration level,

there was no significant difference in the cluster of the higher green space index and the

percentage of people exposed in the lowest (55–59 dB(A)) or the highest noise band of more

than 70 dB(A). In the urban level it was found that lower noise levels can possibly be achieved in

cities with a higher extent of porosity and green space coverage. Finally, in the kernel level a

Geographically Weighted Regression (GWR) analysis was conducted for the identification of

correlations between noise and green. Strong correlations were identified between 60% and 79%,

while a further cluster analysis combined with land cover data revealed that lower noise levels

were detected in the cluster with higher green space coverage. At last, all cities were ranked

according to the calculated noise index.

Jayasooriya, V. M., et al. (2017). "Green infrastructure practices for improvement of

urban air quality." Urban Forestry & Urban Greening 21: 34-47.

Green Infrastructure (GI) practices have shown to be promising in mitigating the air

pollution in urban areas of several cities across the world. GI practices such as trees, green roofs

and green walls are widely used in United States and Europe to mitigate the air pollution.

However, there is yet limited knowledge available in identifying the most suitable GI strategy for

an urban area in improving the air quality. Furthermore, it is evident that Australia is still lagging

behind in adapting GI to mitigate air pollution, compared with US and Europe. Therefore, this

study analyzed the air quality improvement through several GI scenarios consisting of trees,

green roofs and green walls considering a case study area in Melbourne, Australia by using the i-

Tree Eco software. The results were compared with case studies in different cities across the

world. The results showed that the i-Tree Eco software can be successfully applied to an

Australian case study area to quantify the air quality improvement benefits of GI. The results

were further assessed with several environmental, economic and social indicators to identify the

most suitable GI scenarios for the study area. These indicators were quantified using different

methods, to assess the effectiveness of different GI scenarios. The results showed that, trees

provided the highest air pollution removal capability among the different GI considered for the

study area. Combination of different GI such as green roofs and green walls with trees did not

provide a significant increment of air quality improvement however, has provided more local

benefits such as building energy savings. The results obtained from this study were also

beneficial in developing policies related to future GI applications in major cities of Australia for

the air quality improvement.

Helen P. King, J. M., Anil Graves, Richard B. Bradbury, James McGinlay, James M.

Bullock (2017). "Biodiversity and cultural ecosystem benefits in lowland landscapes in

southern England." Journal of Environmental Psychology 53: 185-197.

Evidence of the link between biodiversity and cultural ecosystem benefits (CEB) is

scarce. Participatory workshops were used to explore perceptions of CEB attributable to

biodiversity in lowland arable and semi-natural grassland landscapes in southern England.

Increased biodiversity was found to be associated with greater perceived benefit, mainly at the

habitat and landscape scale. It was, however, difficult to separate the effects of biodiversity from

those of abiotic and human-made features, all of which combined to provide an important sense

of place. Furthermore, CEB were strongly linked with supporting infrastructure, notably public

access. It was observed that CEB were generated through socio-psychological 'pathways' as

people interacted with environmental settings, such as acquiring knowledge, feeling regenerated

and communicating with others. CEB were also attributed to provisioning and regulatory

services, questioning the validity of partitioning cultural services. The findings have implications

for practitioners designing programmes to enhance nature's contribution to people.

Englund, O., et al. (2017). "How to analyse ecosystem services in landscapes—A systematic

review." Ecological Indicators 73: 492-504.

Ecosystem services (ES) is a significant research topic with diverse modelling and

mapping approaches. However, the variety of approaches—along with an inconsistent

terminology—cause uncertainties concerning the choice of methods. This paper identifies and

qualitatively assesses methods for mapping ES in terrestrial landscapes, based on a systematic

review of the scientific literature. It further aims to clarify the associated terminology, in

particular the concept of landscape and landscape scale. In total, 347 cases of ES mapping were

identified in the reviewed papers. Regulating and maintenance services were most commonly

mapped (165), followed by cultural (85), and provisioning services (73). For individual ES, a

large variation in number of mapping cases was found. This variation may either reflect the

perceived importance of the ES, or that different ES can be more or less easily mapped. Overall,

Logical models and Empirical models were most commonly used, followed by Extrapolation,

Simulation/Process models, Data integration, and Direct mapping. Only twelve percent of all ES

mapping cases were validated with empirical data. The review revealed highly diverging views

on the spatial extent of landscapes in studies of ES, and that the term landscape is sometimes

used rather arbitrarily.

Zölch, T., et al. (2016). "Using green infrastructure for urban climate-proofing: An

evaluation of heat mitigation measures at the micro-scale." Urban Forestry & Urban

Greening 20: 305-316.

Urban green infrastructure (UGI) has been increasingly promoted as a key measure to

mitigate heat stress in cities caused by the urban heat island effect and climate change impacts,

including climate variability and extremes. However, comparable information concerning the

performance of different UGI types to moderate such impacts is mostly lacking. This creates

serious challenges for urban planners who need to decide on the most effective measures while

considering spatial and administrative constraints. This study investigates how different types

and quantities of UGI, i.e. trees, green roofs, and green facades, affect pedestrian thermal

comfort. The study was applied to high-density residential areas under current and future

climatic conditions. Climate change will on average increase afternoon Physiological Equivalent

Temperature (PET) values by 2.4 K; however, this could be vastly reduced by different UGI

scenarios. Planting trees had the strongest impact with an average PET reduction of 13%

compared with existing vegetation. Trees shade open spaces and provide evapotranspirative

cooling. Another valuable adaptation option is green facades, which have mitigating effects of

5%–10%. In contrast, the effects of green roofs were negligible. Our results indicate that

increasing the share of green cover did not directly correspond to the magnitude of the PET

reduction. Placing vegetation strategically in heat-exposed areas is more effective than just

aiming at a high percentage of green cover. We conclude that our extensive comparative analysis

provides empirical evidence to support UGI on the micro-scale and assists planners and decision-

makers to effectively select and prioritise concrete measures to adapt to climate change.

Van Renterghem, T. and D. Botteldooren (2016). "View on outdoor vegetation reduces

noise annoyance for dwellers near busy roads." Landscape and Urban Planning 148: 203-

215.

The effect of outdoor vegetation, as seen from the living room's window facing an inner-

city ring road, on the self-reported noise annoyance, was studied. Face-to-face surveys were

taken at 105 participants at their homes in the city of Ghent (Belgium). The living room window,

facing the road, was in all cases highly exposed to road traffic noise and characterized by Lden

levels between 65 and 80 dBA, as taken from the official European Environmental Noise

Directive's city road traffic noise map. All houses were selected to have a pronounced front-back

level difference to rule out this effect. The self-reported extent to which vegetation is visible

through the living room window was shown to be a strong and statistically significant predictor

of the self-reported noise annoyance. The complete absence of view on vegetation results in a

34% chance of being at least moderately annoyed by noise, while this chance reduced to 8% for

respondents answering to have a very pronounced vegetation view, notwithstanding median

Lden levels of 73 dBA at the street-facing facade of the dwelling. Real vision on outdoor

vegetation was shown to be essential - living room (indoor) plants and the mere presence of

vegetation in the neighborhood is insufficient. Road traffic noise facade insulation, measured in-

situ at each dwelling, could not be linked to the self-reported noise annoyance.

Tong, Z., et al. (2016). "Roadside vegetation barrier designs to mitigate near-road air

pollution impacts." Science of The Total Environment 541: 920-927.

With increasing evidence that exposures to air pollution near large roadways increases

risks of a number of adverse human health effects, identifying methods to reduce these exposures

has become a public health priority. Roadside vegetation barriers have shown the potential to

reduce near-road air pollution concentrations; however, the characteristics of these barriers

needed to ensure pollution reductions are not well understood. Designing vegetation barriers to

mitigate near-road air pollution requires a mechanistic understanding of how barrier

configurations affect the transport of traffic-related air pollutants. We first evaluated the

performance of the Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG)

model with Large Eddy Simulation (LES) to capture the effects of vegetation barriers on near-

road air quality, compared against field data. Next, CTAG with LES was employed to explore

the effects of six conceptual roadside vegetation/solid barrier configurations on near-road size-

resolved particle concentrations, governed by dispersion and deposition. Two potentially viable

design options are revealed: a) a wide vegetation barrier with high Leaf Area Density (LAD),

and b) vegetation–solid barrier combinations, i.e., planting trees next to a solid barrier. Both

designs reduce downwind particle concentrations significantly. The findings presented in the

study will assist urban planning and forestry organizations with evaluating different green

infrastructure design options.

Sjöman, H., et al. (2016). "Diversification of the urban forest—Can we afford to exclude

exotic tree species?" Urban Forestry & Urban Greening 18: 237-241.

Introduced tree species represent a substantial component of urban forests in cities all

over the world. Yet there is controversy about the further use of introduced tree species. Many

practice orientated publications, research papers and governmental websites in the fields of urban

planning, urban forestry, and urban ecology argue for planting native species and avoiding

introduced species. Such arguments for native-only species selection are also touted by

environmental groups and the media. Consequently, the debate has sometimes spiralled away

from a sensible and rational platform where invasion risks and biodiversity loss are discussed, to

a groundless and unreasonable argument where exotic species are generally considered incapable

of providing ecosystem services. From a European perspective, we here aim to curate a set of

necessary considerations for current and future discussions on native and non-native plant

material in sustainable urban development. Using examples from Northern and Central Europe

we illustrate that in some regions the catalogue of native tree species may be too limited to fulfil

ecosystem services and resilience in harsh urban environments. A main message from our line of

arguments is that we cannot afford to generally exclude non-native tree species from urban

greening. If “native-only” approaches become incorporated in regional, national or international

policy documents or legislation there is a risk that urban ecosystem resilience will be

compromised, particularly in regions with extreme environmental conditions. Since both

invasion risks and sizes of native species pools vary conspicuously at regional to continental

scales we also argue to adapt urban policies on using non-native trees to regional contexts.

Salmond, J. A., et al. (2016). "Health and climate related ecosystem services provided by

street trees in the urban environment." Environmental Health 15(1): S36.

Urban tree planting initiatives are being actively promoted as a planning tool to enable

urban areas to adapt to and mitigate against climate change, enhance urban sustainability and

improve human health and well-being. However, opportunities for creating new areas of green

space within cities are often limited and tree planting initiatives may be constrained to kerbside

locations. At this scale, the net impact of trees on human health and the local environment is less

clear, and generalised approaches for evaluating their impact are not well developed.

In this review, we use an urban ecosystems services framework to evaluate the direct, and

locally-generated, ecosystems services and disservices provided by street trees. We focus our

review on the services of major importance to human health and well-being which include

‘climate regulation’, ‘air quality regulation’ and ‘aesthetics and cultural services’. These are

themes that are commonly used to justify new street tree or street tree retention initiatives. We

argue that current scientific understanding of the impact of street trees on human health and the

urban environment has been limited by predominantly regional-scale reductionist approaches

which consider vegetation generally and/or single out individual services or impacts without

considering the wider synergistic impacts of street trees on urban ecosystems. This can lead

planners and policymakers towards decision making based on single parameter optimisation

strategies which may be problematic when a single intervention offers different outcomes and

has multiple effects and potential trade-offs in different places.

We suggest that a holistic approach is required to evaluate the services and disservices

provided by street trees at different scales. We provide information to guide decision makers and

planners in their attempts to evaluate the value of vegetation in their local setting. We show that

by ensuring that the specific aim of the intervention, the scale of the desired biophysical effect

and an awareness of a range of impacts guide the choice of i) tree species, ii) location and iii)

density of tree placement, street trees can be an important tool for urban planners and designers

in developing resilient and resourceful cities in an era of climatic change.

Razzaghmanesh, M., et al. (2016). "The role of green roofs in mitigating Urban Heat Island

effects in the metropolitan area of Adelaide, South Australia." Urban Forestry & Urban

Greening 15: 89-102.

Changing an urban environment and replacing vegetated surfaces with low albedo

materials is one of the reasons for increasing temperatures in an urban environment and

consequently also one of the key causes of urban heat island effects. In this study, an

experimental investigation at the micro-scale and also a numerical simulation at the macro-scale

of a typical urban environment in Adelaide were conducted to estimate the potential for

mitigating the UHI effect. The results showed that existing low albedo materials such as asphalt,

metal roofs and brick pavements contribute to the heat island potential. Also, urban development

and a lack of natural vegetation contribute to increased temperatures in cities. The ability of two

types of extensive and intensive green roofs to reduce the surrounding micro-climate temperature

were monitored. The results showed that they have significant cooling effects in summer time

and could behave as an insulation layer to keep buildings warmer in the winter. Furthermore,

different scenarios of adding green roofs to the Adelaide urban environment were investigated

using the Envi–MET model. The scenario modelling of adding green roofs in a typical urban

area in Adelaide, Australia, supported the hypothesis that this can lead to reductions in energy

consumption in the Adelaide urban environment. Also an increased use of other water sensitive

urban design technologies such as green walls and street trees together with the adoption of high

albedo materials is recommended for achieving the optimum efficiency in terms of reducing

urban temperatures and mitigating urban heat island effects.

Rai, P. K. (2016). "Biodiversity of roadside plants and their response to air pollution in an

Indo-Burma hotspot region: implications for urban ecosystem restoration." Journal of

Asia-Pacific Biodiversity 9(1): 47-55.

In recent Anthropocene, biodiversity of urban roadside plants is now increasingly being

realized as an eco-sustainable tool for monitoring and mitigation of air pollution. The present

study aimed to investigate the impact of particulate matter (PM) pollutants on leaf morphology

(stomata), biochemical (heavy metals, protein, and sugars) parameters and enzyme activity

(peroxidase and catalase) of 12 common roadside plant species, growing at two different sites of

Aizawl City, i.e. the Ramrikawn (RKN-Med; polluted peri-urban) site and the Mizoram

University (MZU-Low; less polluted rural) site. The highest dust deposition was noted for the

RKN-Med site on Ficus benghalensis and the lowest in Bauhinia variegate. The plant species

growing at the RKN-Med site showed significant decreases in stomatal size and stomatal index

(p ˂ 0.05). Further, increased concentration of heavy metals (Fe, Cu, and Zn) was recorded at the

RKN-Med site. Moreover, tolerant roadside plants find their suitability for plantation in

ecologically sensitive regions, having implications for urban ecosystem restoration.

Pulighe, G., et al. (2016). "Insights and opportunities from mapping ecosystem services of

urban green spaces and potentials in planning." Ecosystem Services 22, Part A: 1-10.

Urbanization and rapid population growth pose the cities in front of massive challenges

in terms of environmental impacts. This paper explores recent progresses in mapping ecosystem

services provided by urban green infrastructures (GI) and discuss how GI can contribute to

promoting cohesion, resilience and livability toward sustainable and green cities. It also

investigates the interlinkages between ecosystem services paradigm, mapping approaches at

urban level and benefits provided for human well-being. A literature study focusing on recent

research papers is conducted, highlighting new trends on methods and data, unexplored

developments and opportunities on literature regarding mapping green infrastructures with

respect to planning, management and ecosystem services’ provision. Additionally, an in-depth

analysis of selected case studies synthesizes and discusses key insights of quantitative results

related to key ecosystem services mapping approaches. The results indicate that mapping efforts

integrates multiple disciplines, combining advanced technology and sophisticated models and

methods. We argue that mapping ecosystem services would allow urban designers and planning

practitioners to help and inform policymakers during the decision process and management of

urban landscapes.

Pinho, P., et al. (2016). "Evaluating green infrastructure in urban environments using a

multi-taxa and functional diversity approach." Environmental Research 147: 601-610.

Forested areas within cities host a large number of species, responsible for many

ecosystem services in urban areas. The biodiversity in these areas is influenced by human

disturbances such as atmospheric pollution and urban heat island effect. To ameliorate the effects

of these factors, an increase in urban green areas is often considered sufficient. However, this

approach assumes that all types of green cover have the same importance for species. Our aim

was to show that not all forested green areas are equal in importance for species, but that based

on a multi-taxa and functional diversity approach it is possible to value green infrastructure in

urban environments. After evaluating the diversity of lichens, butterflies and other-arthropods,

birds and mammals in 31 Mediterranean urban forests in south-west Europe (Almada, Portugal),

bird and lichen functional groups responsive to urbanization were found. A community shift

(tolerant species replacing sensitive ones) along the urbanization gradient was found, and this

must be considered when using these groups as indicators of the effect of urbanization. Bird and

lichen functional groups were then analyzed together with the characteristics of the forests and

their surroundings. Our results showed that, contrary to previous assumptions, vegetation density

and more importantly the amount of urban areas around the forest (matrix), are more important

for biodiversity than forest quantity alone. This indicated that not all types of forested green

areas have the same importance for biodiversity. An index of forest functional diversity was then

calculated for all sampled forests of the area. This could help decision-makers to improve the

management of urban green infrastructures with the goal of increasing functionality and

ultimately ecosystem services in urban areas.

Pena, J., et al. (2016). "The green infrastructure of a highly-urbanized neotropical city: the

role of the urban vegetation in preserving native biodiversity." Capa 11(4): 66-78.

The composition of the urban vegetation that comprises the green infrastructure of a

highly urbanized Neotropical city was mapped and described in order to assess how it can be

used to preserve and maintain urban biodiversity. Supervised classification was used, followed

by Map Algebra methodology, to identify the elements that comprise the green infrastructure of

the southern region of Belo Horizonte (Minas Gerais, Brazil). Species composition of the street

trees community was also assessed. Almost half of the study area is occupied by 12 types of

woody and herbaceous vegetation, composed mostly by urban parks and gardens. Forty-one

percent of the almost 90,000 street trees is composed by 10 species from which only four are

native. These results show that the green infrastructure of this urban landscape is comprised by a

large amount of different types of green elements, and has a great potential for biodiversity

conservation. However, management strategies are needed such as better planning of the urban

afforestation process, increasing street tree species richness. This study is the first step towards a

better understanding of how such urban landscape influences local biodiversity.

Okunlola, A. I., et al. (2016). "Air Pollution Tolerance Index (APTI) and carbon

sequestration of selected trees and shrubs for urban development in Akure Ondo State,

Southwest Nigeria." Brazilian Journal of Biological Sciences 3(6): 395-405.

Urban green space is a collection of trees and shrubs growing in urban area. Green plants

are well known for their abilities to reduce air and noise pollution. It is important that plants used

for the development of urban landscaping must be tolerant to air pollutants. There must be some

criteria to select tolerant plants for urban landscaping design and for that two indices viz. Air

Pollution Tolerance Index (APTI) and carbon sequestration can be a good tool. Thus this study

was carried out to assess the efficiency of urban trees (Tabebuia rosea, Polyalthia longifolia,

Delonix regia and Raphia farinifera) and shrubs (Ficus spp) to tolerate air pollution and potential

for carbon sequestration in Akure, Ondo State, Nigeria in 2015. The sites were sampled from

Akure City Major Road, from Oloko Junction to Oba-Ile. The plant species identified at the

sample area were Ficus spp, Tabebuia rosea, Polyalthia longifolia, Delonix regia and Raphia

farinifera. The assessment of the ascorbic acid, pH, relative water content and total chlorophyll

content of the leaves of the identified plant species was done to determine the APTI. The APTI

of the plant ranged from 5.11 to 9.31 with Tabebuia rosea having the highest value which

indicates it’s high tolerance of air pollutants from the assessment and Raffia farinifera with the

lowest value and least tolerant. The biomass of the trees species were estimated for the

quantification of the amount of carbon sequestered and the absorbed CO2 in the plant. Tabebuia

rosea also had the highest carbon sequestered (10,074 kg) and Delonix regia having the lowest of

4,702.50 kg.

Nowak, D. J., et al. (2016). "Urban forest structure, ecosystem services and change in

Syracuse, NY." Urban Ecosystems 19(4): 1455-1477.

The tree population within the City of Syracuse was assessed using a random sampling of

plots in 1999, 2001 and 2009 to determine how the population and the ecosystem services these

trees provide have changed over time. Ecosystem services and values for carbon sequestration,

air pollution removal and changes in building energy use were derived using the i-Tree Eco

model. In addition, photo interpretation of aerial images was used to determine changes in tree

cover between the mid-1990s and 2009. Between the mid-1990s and 2003, tree cover in

Syracuse exhibited a decline from 27.5 to 25.9 %, but subsequently increased to 26.9 % by 2009.

The total tree population exhibited a similar pattern, dropping from 881,000 trees in 1999 to

862,000 in 2001, and then increasing to 1,087,000 trees in 2009. Most of this increase in the

urban tree population is due to invasive or pioneer trees species, particularly Rhamnus cathartica,

which has more than tripled in population between 2001 and 2009. Insects such as gypsy moth

and emerald ash borer pose a substantial risk to altering future urban forest composition. The

annual ecosystem services provided by the urban forest in relation to carbon sequestration, air

pollution removal and reduction in building energy use are estimated at about $2.4 million per

year. An improved understanding of urban forests and how they are changing can facilitate better

management plans to sustain ecosystem services and desired forest structure for future

generations.

Nash, C., et al. (2016). "Initial insights on the biodiversity potential of biosolar roofs: a

London Olympic Park green roof case study." Israel Journal of Ecology & Evolution 62(1-

2): 74-87.

Cities dominated by impervious artificial surfaces can experience a multitude of negative

environmental impacts. Restoration of green infrastructure has been identified as a mechanism

for increasing urban resilience, enabling cities to transition towards sustainable futures in the

face of climate-driven change. Building rooftops represent a viable space for integrating new

green infrastructure into high-density urban areas. Urban rooftops also provide prime locations

for photovoltaic (PV) systems. There is an increasing recognition that these two technologies can

be combined to deliver reciprocal benefits in terms of energy efficiency and biodiversity targets.

Scarcity of scientific evaluation of the interaction between PVs and green roofs means that the

potential benefits are currently poorly understood. This study documents evidence from a

biodiversity monitoring study of a substantial biosolar roof installed in the Queen Elizabeth

Olympic Park. Vegetation and invertebrate communities were sampled and habitat structure

measured in relation to habitat niches on the roof, including PV panels. Ninety-two plant species

were recorded on the roof and variation in vegetation structure associated with proximity to PV

panels was identified. Almost 50% of target invertebrate species collected were designated of

conservation importance. Arthropod distribution varied in relation to habitat niches on the roof.

The overall aim of the Main Press Centre building green roof design was to create a mosaic of

habitats to enhance biodiversity, and the results of the study suggest that PV panels can

contribute to niche diversity on a green roof. Further detailed study is required to fully

characterise the effects of PV panel density on biodiversity.

Mguni, P., et al. (2016). "Sustainable urban drainage systems: examining the potential for

green infrastructure-based stormwater management for Sub-Saharan cities." Natural

Hazards 82(2): 241-257.

Green infrastructure (GI)-based approaches to urban drainage such as sustainable urban

drainage systems (SUDS) could provide Sub-Saharan cities with an opportunity to address

projected climate change impacts and existing deficits in their drainage infrastructure, even more

so due to the synergies between an enhanced green infrastructure stock and sustainable urban

development. The objective of this paper was to assess the theoretical value of using green

infrastructure for stormwater management as an alternative and supplement to conventional pipe-

based stormwater management systems. A SWOT analysis is performed to assess the potential

that SUDS hold if adopted and implemented in Sub-Saharan cities. This analysis is based on a

review of sustainable stormwater management as well as urban planning and governance

literature. Results show that despite seemingly significant barriers to the adoption of SUDS in

Sub-Saharan cities such as low prioritization on the urban agenda and lack of data among others,

the concept may hold valuable potential for flood risk reduction, even more so due to its multi-

functionality and synergies with urban agriculture, amenity and water supply. In the light of the

existing threats and weaknesses, it is recommended that GI-based SUDS may be best approached

initially as experiments at a local community scale.

Mensah, C. A., et al. (2016). "Enhancing quality of life through the lens of green spaces: A

systematic review approach." International Journal of Wellbeing 6(1).

Improvingcitizens’qualityoflifeisastatedpriorityofmanygovernmentsinboththe global

north and south. However, efforts to achieve this often focus on socio-economic measures, with

limited attention to the contributions of environmental variables such as green spaces. This paper

sought to bridge this knowledge gap by tracing the linkages between green spaces and quality of

life, and how these connections can inform policy development in order to assist governments to

achieve positive outcomes for quality of life. The paper took a theoretical approach by utilising

the systematic review method. In all, 452 publications were included in this review, and rigorous

content analysis was employed to retrieve relevant data. Green spaces were found to provide

various social, economic, and environmental benefits, which in turn improve physical,

psychological, emotional, social, and material wellbeing of individuals and thus enhance quality

of life. It is therefore strongly recommended that conservation of green spaces should be

integrated into national health, environmental and socio-economic policies in order to promote

effective utilisation of green spaces to enhance citizens’ overall quality of life.

McPherson, E. G., et al. (2016). "Structure, function and value of street trees in California,

USA." Urban Forestry & Urban Greening 17: 104-115.

This study compiled recent inventory data from 929,823 street trees in 50 cities to

determine trends in tree number and density, identify priority investments and create baseline

data against which the efficacy of future practices can be evaluated. The number of street trees

increased from 5.9 million in 1988 to 9.1 million in 2014, about one for every four residents.

Street tree density declined from 65.6 to 46.6 trees per km, nearly a 30% drop. City streets are at

36.3% of full stocking. State-wide, only London planetree (Platanus × hispanica) comprises over

10% of the total, suggesting good state-wide species diversity. However, at the city scale, 39

communities were overly reliant on a single species. The state’s street trees remove 567,748 t

CO2 (92,253 t se) annually, equivalent to taking 120,000 cars off the road. Their asset value is

$2.49 billion ($75.1 million se). The annual value (USD) of all ecosystem services is $1.0 billion

($58.3 million se), or $110.63 per tree ($29.17 per capita). Given an average annual per tree

management cost of $19.00, $5.82 in benefit is returned for every $1 spent. Management

implications could include establishing an aggressive program to plant the 16 million vacant sites

and replace removed trees, while restricting planting of overabundant species. Given the tree

population’s youth there is likely need to invest in pruning young trees for structure and form,

which can reduce subsequent costs for treating defects in mature trees.

McDonald, R., et al. (2016). Planting healthy air: a global analysis of the role of urban trees

in addressing particulate matter pollution and extreme heat. Arlington, The Nature

Conservancy.

Heatwaves are one of the world's most underestimated threats, killing more than 12,000

people every year around the world - more than any other weather-related event. And heat is

especially dangerous in cities, which tend to be much warmer than surrounding less-developed

areas. On top of that, cities tend to have higher levels of air pollution, which contribute to more

than 3 million deaths every year. With 70 percent of the world's population predicted to live in

cities by 2050, heat and air pollution constitute a major public health concern. One relatively

simple solution to this problem, plant more trees in cities. Trees cool the air by casting shade and

releasing water vapor, and their leaves can filter out fine particulate matter (PM) - one of the

most dangerous forms of air pollution, generated from burning biomass and fossil fuels. The

Nature Conservancy has studied the effects of trees on air quality in 245 of the world's largest

cities and documented the findings in the Planting Healthy Air report. The Planting Healthy Air

report documents which cities stand to benefit most from tree plantings, in terms of both heat and

PM reduction, and how much investment would be required to achieve meaningful benefits. The

analysis found that investing just US$4 per resident in each of these cities in tree planting efforts

could improve the health of millions of people, and that trees are as cost-effective as many other

common solutions. Most of the cooling and filtering effects created by trees are fairly localized,

so densely populated cities - as well as those with higher overall pollution levels - tend to see the

highest overall return on investment (ROI) from tree plantings. The localized nature of trees'

effects, however, means that particular neighborhoods in virtually any city could benefit from

plantings. City planners can even target plantings to protect areas with especially vulnerable

populations - such as near schools and hospitals - or use trees as a screen against PM coming

from highways and industrial areas. While trees alone can't solve the entirely of cities' air and

heat problems, they are a critical piece of the puzzle. The report shows that even a conservative

global investment in urban trees can save tens of thousands of lives.

Livesley, S. J., et al. (2016). "The Urban Forest and Ecosystem Services: Impacts on Urban

Water, Heat, and Pollution Cycles at the Tree, Street, and City Scale." Journal of

Environmental Quality 45(1): 119-124.

Many environmental challenges are exacerbated within the urban landscape, such as

stormwater runoff and flood risk, chemical and particulate pollution of urban air, soil and water,

the urban heat island, and summer heat waves. Urban trees, and the urban forest as a whole, can

be managed to have an impact on the urban water, heat, carbon and pollution cycles. However,

there is an increasing need for empirical evidence as to the magnitude of the impacts, both

beneficial and adverse, that urban trees can provide and the role that climatic region and built

landscape circumstance play in modifying those impacts. This special section presents new

research that advances our knowledge of the ecological and environmental services provided by

the urban forest. The 14 studies included provide a global perspective on the role of trees in

towns and cities from five continents. Some studies provide evidence for the cooling benefit of

the local microclimate in urban green space with and without trees. Other studies focus solely on

the cooling benefit of urban tree transpiration at a mesoscale or on cooling from canopy shade at

a street and pedestrian scale. Other studies are concerned with tree species differences in canopy

interception of rainfall, water uptake from biofilter systems, and water quality improvements

through nutrient uptake from stormwater runoff. Research reported here also considers both the

positive and the negative impacts of trees on air quality, through the role of trees in removing air

pollutants such as ozone as well as in releasing potentially harmful volatile organic compounds

and allergenic particulates. A transdisciplinary framework to support future urban forest research

is proposed to better understand and communicate the role of urban trees in urban

biogeochemical cycles that are highly disturbed, highly managed, and of paramount importance

to human health and well-being.

Lin, M.-Y., et al. (2016). "The effects of vegetation barriers on near-road ultrafine particle

number and carbon monoxide concentrations." Science of The Total Environment 553:

372-379.

Numerous studies have shown that people living in near-roadway communities (within

100 m of the road) are exposed to high ultrafine particle (UFP) number concentrations, which

may be associated with adverse health effects. Vegetation barriers have been shown to affect

pollutant transport via particle deposition to leaves and altering the dispersion of emission

plumes, which in turn would modify the exposure of near-roadway communities to traffic-related

UFPs. In this study, both stationary (equipped with a Scanning Mobility Particle Sizer, SMPS)

and mobile (equipped with Fast Mobility Particle Sizer, FMPS) measurements were conducted to

investigate the effects of vegetation barriers on downwind UFP (particle diameters ranging from

14 to 102 nm) concentrations at two sites in North Carolina, USA. One site had mainly

deciduous vegetation while the other was primarily coniferous; both sites have a nearby open

field without the vegetation barriers along the same stretch of limited access road, which served

as a reference. During downwind conditions (traffic emissions transported towards the vegetation

barrier) and when the wind speed was above or equal to 0.5 m/s, field measurements indicated

that vegetation barriers with full foliage reduced UFP and CO concentrations by 37.7–63.6% and

23.6–56.1%, respectively. When the test was repeated at the same sites during winter periods

when deciduous foliage was reduced, the deciduous barrier during winter showed no significant

change in UFP concentration before and after the barrier. Results from the stationary (using

SMPS) and mobile (using FMPS) measurements for UFP total number concentrations generally

agreed to within 20%.

Li, X.-B., et al. (2016). "The impacts of roadside vegetation barriers on the dispersion of

gaseous traffic pollution in urban street canyons." Urban Forestry & Urban Greening 17:

80-91.

Vegetation barriers have been widely applied along urban streets to improve roadside air

quality. For a deep investigation of their influences, field measurements and numerical

simulations are performed in this study. Carbon monoxide (CO) is selected as a representative of

gaseous traffic emissions for both field observations and numerical models. Computational Fluid

Dynamics (CFD) models of the standard k-ε turbulent model and Eulerian approach for species

transport are solved by FLUENT solver. Results obtained from numerical simulations show a

good agreement with field observations on the distribution of roadside CO. In perpendicular

wind conditions, both field observations and numerical simulations present a prominent CO

reduction over the slow lanes (footpath and bikeway) when vegetation barriers exist. To

effectively mitigate roadside air pollution, numerical simulations also provide the optimal

heights for roadside vegetation barriers in the given street canyons. For street canyons with an

aspect ratio (the ratio of building height to street width) ranging from 0.3 to 1.67, 1.1 m can be

used as an optimal height, and 2.0 m could serve as an alternative if tall vegetation barriers are

considered. For street canyons with an aspect ratio of lower than 0.3, 0.9 m to 2.5 m can be

considered as the optimal heights for roadside vegetation barriers. According to sensitivity

analysis, the optimal heights for vegetation barriers are largely insensitive to wind velocities in

the given street canyons. In the more complicated urban street canyons and complex

meteorological conditions, the optimal heights can be determined by specific numerical

simulations. These findings are expected to provide important insights into alleviation of gaseous

mobile emissions in terms of vegetation barrier design in urban streets.

La Rosa, D., et al. (2016). "Indicators of Cultural Ecosystem Services for urban planning:

A review." Ecological Indicators 61, Part 1: 74-89.

The concept of Ecosystem Services has gained traction on the scientific agenda and has

found its way into research on urban environments. Cities and towns, like any other ecosystem,

provide specific services to their inhabitants and communities and they are benefited by

surrounding ecosystems as well. Among the different categories, typical Ecosystem Services

categories such as food production and erosion control usually have a lesser importance within

urban contexts. However, the very diverse range of land uses and ecosystems in urban contexts

provide specific Cultural Ecosystem Services including recreational, cultural and educational

values. However, to date only limited attention has been given to the provision of Cultural

Ecosystem Services (CES), especially considering the relevant benefits that communities and

urban planning processes can derive from them. In this document we review existing approaches

for the assessment of CES in urban contexts and provide a critical overview of how indicators

are used to assess and measure CES. We first conduct a literature review on the indicators used

for CES in urban contexts then the paper addresses some specific issues with reference to both

operability and benefits of the use of CES indicators for urban planning and management. Our

results show that existing CES indicators have limited usability for urban planning and

management. Moreover a lack of appropriate data use is a significant obstacle for proper CES

assessment. This impacts the potential for sustainable decision-making concerning CES in urban

contexts. These issues, together with fact that most identified indicators are proxy ones, identify

an urgent need to develop proper assessment indicators for CES.

Kim, H. W. and Y. Park (2016). "Urban green infrastructure and local flooding: The

impact of landscape patterns on peak runoff in four Texas MSAs." Applied Geography 77:

72-81.

Even though there is a general acknowledgement that green infrastructure can have a

positive role in reducing stormwater runoff, few studies have explored how specific spatial

configurations of landscape—one of the critical components of green infrastructure—could

influence runoff generation. This study attempts to address this gap by examining the landscape

patterns in terms of size, shape, isolation, and connectivity across the four largest metropolitan

areas in Texas, using landscape ecology metrics. The outcomes indicate that larger, less

fragmented, and more connected landscape patterns are likely to mediate the mean annual peak

runoff. In contrast, larger developments of complex shapes with more edges, clustered, and

connected are likely to augment the peak runoff. The findings of this paper provide empirical

evidences for policy makers to further the importance of interconnection and clusters of green

infrastructure and plan strategic green hubs and corridors to more effectively manage stormwater

runoff.

Hosseini, S. A. O., et al. (2016). "Effects of geometric design of forest road and roadside

vegetation on traffic noise reduction." Journal of Forestry Research 27(2): 463-468.

Geometric design of forest roads and design of their landscapes can reduce noise

pollution and its harmful effects on human health. We investigated the effects of technical and

biological parameters such as geometric road design and various roadside tree stands on reducing

noise pollution according to the tree density and distance from roadway in Darabkola Forests,

Sari, Iran. We recorded the noise generated by a car (Land Rover) relative to changes in

longitudinal slope, horizontal curve radius and type of road pavement. We also measured noise

levels according to roadside tree density and stand type (coniferous and hardwood) in 40

rectangular plots of three widths (25, 100 and 300 m) and 50 m length that were randomly

demarcated along forest roads. The changes in noise level were recorded using a decibel meter

with an accuracy of ±1.5 dB and resolution of 0.1 dB. Noise levels were higher alongside

unpaved roads than alongside paved roads. There was an inverse relationship between the

measured noise level and horizontal curve radius. The rate of noise level on horizontal curve

with a radius less than 30, 30–45 m and more than 45 m were 64.8, 70.8 and 75.9 dB,

respectively. The noise level increased with the increasing longitudinal slope of the road. There

was a significant difference between the noise level on slopes less than 3 % (67 dB) and 3–8 %

(71.2 dB) in comparison with slopes greater than 8 % (77.8 dB), (p < 0.05). Pinus brutia L.

reduced the noise level more (about 6 dB) in stands of 1/3 density of mixed hardwoods within

25 m from middle of the road. Careful design of geometric properties of forest roads as well as

planting coniferous trees with hardwoods is a suitable solution for reducing noise pollution.

Hoang, L. and R. A. Fenner (2016). "System interactions of stormwater management using

sustainable urban drainage systems and green infrastructure." Urban Water Journal

13(7): 739-758.

This study explores system interactions of stormwater management solutions using

Sustainable Urban Drainage System (SuDS) and Green Infrastructure (GI) within the wider

urban landscape. A series of interdependencies between urban components relating to

stormwater management are identified. These include physical interdependency, geographical

interdependency, cyber interdependency and logical interdependency, as defined by Peerenboom

(2001). Stormwater management using SuDS/GI are viewed according to their Hydrological,

Ecological and the Built Environment functions during events up to the design rain (non-flood

condition) and during controlled exceedance and uncontrolled inundation (flood condition). The

inclusion of SuDS/GI into the urban fabric is shown to modify urban functional and relational

interdependencies under both these conditions. Within the context of the UK, there are

fragmented responsibilities across planning scales created by SuDS/GI solutions which have not

addressed the relational complexities that exist between agencies and competent authorities. The

paper identifies the key barriers towards effective adoption of SuDS/GI within the context of the

UK as physical barriers, perception/information barriers and organisational barriers.

Grote, R., et al. (2016). "Functional traits of urban trees: air pollution mitigation

potential." Frontiers in Ecology and the Environment 14(10): 543-550.

In an increasingly urbanized world, air pollution mitigation is considered one of most

important issues in city planning. Urban trees help to improve air quality by facilitating

widespread deposition of various gases and particles through the provision of large surface areas

as well as through their influence on microclimate and air turbulence. However, many of these

trees produce wind-dispersed pollen (a known allergen) and emit a range of gaseous substances

that take part in photochemical reactions – all of which can negatively affect air quality. The

degree to which these air-quality impacts are manifested depends on species-specific tree

properties: that is, their “traits”. We summarize and discuss the current knowledge on how such

traits affect urban air pollution. We also present aggregated traits of some of the most common

tree species in Europe, which can be used as a decision-support tool for city planning and for

improving urban air-quality models.

Gromke, C., et al. (2016). "Influence of roadside hedgerows on air quality in urban street

canyons." Atmospheric Environment 139: 75-86.

Understanding pollutant dispersion in the urban environment is an important aspect of

providing solutions to reduce personal exposure to vehicle emissions. To this end, the dispersion

of gaseous traffic pollutants in urban street canyons with roadside hedges was investigated. The

study was performed in an atmospheric boundary layer wind tunnel using a reduced-scale

(M = 1:150) canyon model with a street-width-to-building-height ratio of W/H = 2 and a street-

length-to-building-height ratio of L/H = 10. Various hedge configurations of differing height,

permeability and longitudinal segmentation (continuous over street length L or discontinuous

with clearings) were investigated. Two arrangements were examined: (i) two eccentric

hedgerows sidewise of the main traffic lanes and (ii) one central hedgerow between the main

traffic lanes. In addition, selected configurations of low boundary walls, i.e. solid barriers, were

examined. For a perpendicular approach wind and in the presence of continuous hedgerows,

improvements in air quality in the center area of the street canyon were found in comparison to

the hedge-free reference scenario. The pollutant reductions were greater for the central hedge

arrangements than for the sidewise arrangements. Area-averaged reductions between 46 and 61%

were observed at pedestrian head height level on the leeward side in front of the building for the

centrally arranged hedges and between 18 and 39% for the two hedges arranged sidewise.

Corresponding area-averaged reductions ranging from 39 to 55% and from 1 to 20% were found

at the bottom of the building facades on the leeward side. Improvements were also found in the

areas at the lateral canyon ends next to the crossings for the central hedge arrangements. For the

sidewise arrangements, increases in traffic pollutants were generally observed. However, since

the concentrations in the end areas were considerably lower compared to those in the center area,

an overall improvement remained for the street canyon. The configuration of a sidewise arranged

discontinuous hedgerow resulted in general in area-averaged increases in concentrations in the

range of 3–19%. For a parallel approach wind, reduced concentrations of up to 30% at the

facades and up to 60% at pedestrian level were measured with a sidewise continuous hedgerow

arrangement. It is concluded that continuous hedgerows can effectively be employed to control

concentrations of traffic pollutants in urban street canyons. They can advantageously affect the

air quality at street level and can be a significant remedy to the pedestrians’ and residents’

exposure in the most polluted center area of a street canyon.

Green, T. L., et al. (2016). "Insurance Value of Green Infrastructure in and Around

Cities." Ecosystems 19(6): 1051-1063.

The combination of climate change and urbanization projected to occur until 2050 poses

new challenges for land-use planning, not least in terms of reducing urban vulnerability to

hazards from projected increases in the frequency and intensity of climate extremes. Interest in

investments in green infrastructure (interconnected systems of parks, wetlands, gardens and other

green spaces), as well as in restoration of urban ecosystems as part of such adaptation strategies,

is growing worldwide. Previous research has highlighted the insurance value of ecosystems in

securing the supply of ecosystem services in the face of disturbance and change, yet this

literature neglects urban areas even though urban populations are often highly vulnerable. We

revisit the insurance value literature to examine the applicability of the concept in urban

contexts, illustrating it with two case studies: watersheds providing drinking water for residents

of Vancouver, Canada; and private gardens ensuring connectedness between other parts of urban

green infrastructure in London, UK. Our research supports the notion that investments in green

infrastructure can enhance insurance value, reducing vulnerability and the costs of adaptation to

climate change and other environmental change. Although we recommend that urban authorities

consider the insurance value of ecosystems in their decision-making matrix, we advise caution in

relying upon monetary evaluations of insurance value. We conclude by identifying actions and

management strategies oriented to maintain or enhance the insurance value of urban ecosystems.

Ecosystems that are themselves resilient to external disturbances are better able to provide

insurance for broader social–ecological systems.

Fulcher, A., et al. (2016). "The next ten years: Strategic vision of water resources for

nursery producers." HortTechnology 26(2): 121-132.

Nursery and greenhouse producers, research and extension faculty, and representatives

from allied fields collaborated to formulate a renewed vision to address water issues affecting

growers over the next 10 years. The authors maintained the original container irrigation

perspective published in “Strategic vision of container nursery irrigation in the next ten years,”

yet broadened the perspective to include additional challenges that face nursery crop producers

today and in the future. Water availability, quality, and related issues continue to garner

widespread attention. Irrigation practices remain largely unchanged due to existing irrigation

system infrastructure and minimal changes in state and federal regulations. Recent concerns over

urbanization and population growth, increased climate variability, and advancements in state and

federal regulations, including new groundwater withdrawal limitations, have provided an

inducement for growers to adopt efficient and innovative practices. Information in support of the

overarching issues and projected outcomes are discussed within.

Edmondson, J. L., et al. (2016). "Soil surface temperatures reveal moderation of the urban

heat island effect by trees and shrubs." Scientific Reports 6.

Urban areas are major contributors to air pollution and climate change, causing impacts

on human health that are ampli ed by the microclimatological e ects of buildings and grey

infrastructure through the urban heat island (UHI) e ect. Urban greenspaces may be important in

reducing surface temperature extremes, but their e ects have not been investigated at a city-wide

scale. Across a mid- sized UK city we buried temperature loggers at the surface of greenspace

soils at 100 sites, stratied by proximity to city centre, vegetation cover and land-use. Mean daily

soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city

outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum

daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but

tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend

to be smaller, were less e ective at reducing summer soil surface temperatures. Our findings

reveal that the UHI e ects soil temperatures at a city-wide scale, and that in their moderating

urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts

of urbanization on microclimate, soil processes and human health.

Ziter, C. (2015). "The biodiversity–ecosystem service relationship in urban areas: a

quantitative review." Oikos.

By 2050, up to 75% of people globally will live in cities. Despite the potential

ramifications of this urbanization for ecosystem services (ES), and the importance of locally

produced ES for the health and wellbeing of urban residents, syntheses addressing the underlying

ecology of ES provision rarely include urban areas. Here, I conduct a quantitative review of

urban ES studies in the ecological literature, synthesizing trends across the discipline. I also

quantify the extent to which this work considers the organisms and ecosystem components

responsible for ES provision using two approaches: assessment of biodiversity–ES relationships,

and an adaptation of the service provider concept. The majority of urban ES studies were

conducted in western, developed countries, and typically assessed a single service in a single city

– largely ignoring ES synergies and tradeoffs, and cross-city comparisons. While several

different ES are studied in urban ecosystems, the field is dominated by weather and climate-

related regulating services, with assessments of cultural services particularly lacking. Most

studies described a habitat type as the service provider; however, studies that considered the

biodiversity–ES relationship were more likely to identify a specific functional group,

community, or population as the key provider of an ES. The biodiversity–ES relationship itself

was most frequently characterized as dependent on the composition of species, functional traits,

or structures, rather than correlated with the magnitude of any specific biodiversity metric. While

the study of ES in urban ecosystems is increasing, there exists considerable room for further

research. Future studies would benefit by expanding the number and categories of ES assessed

within and across cities, as well as broadening the geographical scope of urban ES research.

Biodiversity–ES assessments in urban ecosystems would also benefit from an expansion of the

biodiversity types considered, particularly regarding non-species based approaches, and

consideration of non-native and invasive species.

Yang, J., et al. (2015). "Ranking the suitability of common urban tree species for

controlling PM2.5 pollution." Atmospheric Pollution Research 6(2): 267-277.

Pollution caused by particles with aerodynamic diameters less than 2.5 μm (PM2.5) is

now a major environmental problem in many Asian cities. Planting more trees has been

suggested as an unconventional approach to alleviate the problem. In this study, we developed a

ranking approach to evaluate the PM2.5 removal efficiency, negative impacts on air quality, and

the suitability to urban environments of commonly occurring urban tree species. The results

showed that the most frequently occurring tree species in global cities were not the best

performers in removing PM2.5. Among the ten most frequently occurring tree species, only

London plane (Platanus acerifolia (Aiton) Wild.), silver maple (Acer saccharinum L.) and honey

locust (Gleditsia triacanthos L.) were ranked above average. However, there is great potential for

improving the removal of PM2.5 from urban air by using species that have high PM2.5 removal

efficiency, especially conifer species. Use of conifer species requires choosing the correct gender

and matching trees with appropriate sites. The results from this study can assist environmental

management agencies in the selection of tree species for urban greening projects focusing on

PM2.5 control.

Voskamp, I. M. and F. H. M. Van de Ven (2015). "Planning support system for climate

adaptation: Composing effective sets of blue-green measures to reduce urban vulnerability

to extreme weather events." Building and Environment 83: 159-167.

The risk of pluvial flooding, heat stress and drought is increasing due to climate change.

To increase urban resilience to extreme weather events, it is essential to combine green and blue

infrastructure and link enhanced storage capacity in periods of water surplus with moments of

water shortage as well as water availability with heat stress. ‘Blue-green measures’ is a collective

term for sustainable green and blue infrastructure that utilises underlying ecosystem functions to

deliver multiple benefits: for example, cooling via evapotranspiration, water storage for heavy

rainfall events, discharge peak attenuation, seasonal water storage, and groundwater recharge.

Measures contribute most to climate adaptation when implemented in combinations. Such

packages of blue-green measures capitalize upon the synergistic interactions between ecosystem

functions and hence enhance multiple vulnerability reduction capacities. Moreover, combining

blue-green measures enables using their unique potential at different spatial scales and

establishing hydrologic connectivity. This paper proposes a framework for a planning support

system and a tool to select adaptation measures to support urban planners in collaboratively

finding site-specific sets of blue-green measures for a particular urban reconstruction project.

With the proposed framework users can evaluate appropriateness of specific adaptation measures

for a particular location and compose effective packages of blue-green measures to handle

flooding, drought and heat stress. It is concluded that the framework: 1) enables incorporating

knowledge on urban climate adaptation and ecosystem services in a communicative urban

planning process, 2) guides the selection of a coherent and effective package of blue-green

adaptation measures.

Van Renterghem, T., et al. (2015). "Using natural means to reduce surface transport noise

during propagation outdoors." Applied Acoustics 92: 86-101.

This paper reviews ways of reducing surface transport noise by natural means. The noise

abatement solutions of interest can be easily (visually) incorporated in the landscape or help with

greening the (sub)urban environment. They include vegetated surfaces (applied to faces or tops

of noise walls and on buildings’ façades and roofs), caged piles of stones (gabions), vegetation

belts (tree belts, shrub zones and hedges), earth berms and various ways of exploiting ground-

surface-related effects. The ideas presented in this overview have been tested in the laboratory

and/or numerically evaluated in order to assess or enhance the noise abatement they could

provide. Some in-situ experiments are discussed as well. When well designed, such natural

devices have the potential to abate surface transport noise, possibly by complementing and

sometimes improving common (non-natural) noise reducing devices or measures. Their

applicability strongly depends on the available space reserved for the noise abatement and the

receiver position.

Tóth, A., et al. (2015). "Green infrastructure: a strategic tool for climate change mitigation

in urban environments." Ecology & Safety 9: 132-138.

The changing climate has a significant negative impact on urban environments,

influencing thereby the quality of life of urban residents and causing a range of problems in

urban areas worldwide. There is a need for efficient urban planning and design tools, which can

mitigate these negative effects. Green infrastructure represents a tool to create more resilient and

sustainable urban environments by greening open spaces in our cities. Green structures and

greenery elements improve the urban microclimate and reduce noise, dustiness, the heat island

effect and help to manage urban stormwater. Therefore, it is crucial to protect and improve

existing green spaces, enhance their connectedness and utilise unconventional areas for creating

new green spaces which would improve the health of urban landscapes. Here, greening of roofs,

walls, brownfields and other empty spaces comes into play. They still represent an unutilised

potential of contemporary urban landscapes. Landscape Architecture as a field of research and

design practice plays a crucial role in developing innovative tools, planning and designing green

infrastructure which will contribute to creation of sustainable and multifunctional urban

landscapes of the future.

Tong, Z., et al. (2015). "Quantifying the effect of vegetation on near-road air quality using

brief campaigns." Environ Pollut 201.

Many reports of trees' impacts on urban air quality neglect pattern and process at the

landscape scale. Here, we describe brief campaigns to quantify the effect of trees on the

dispersion of airborne particu- lates using high time resolution measurements along short

transects away from roads. Campaigns near major highways in Queens, NY showed frequent,

stochastic spikes in PM2.5. The polydisperse PM2.5 class poorly represented the behavior of

discrete classes. A transect across a lawn with trees had fewer spikes in PM2.5 concentration but

decreased more gradually than a transect crossing a treeless lawn. This coincided with decreased

Turbulence Kinetic Energy downwind of trees, indicating recirculation, longer residence times

and decreased dispersion. Simply planting trees can increase local pollution concen- trations,

which is a special concern if the intent is to protect vulnerable populations. Emphasizing

deposition to leaf surfaces obscures the dominant impact of aerodynamics on local concentration.

Sonntag-Ostrom, E., et al. (2015). "Can rehabilitation in boreal forests help recovery from

exhaustion disorder? The randomised clinical trial ForRest." Scandinavian Journal of

Forest Research 30(8): 732-748.

Modern society is faced with increasing incidence of mental and behavioural disorders.

The objective of this study was to evaluate whether visits to boreal forests can be utilised for

rehabilitation from exhaustion disorder (ED). This randomised controlled trial comprised of a

forest rehabilitation group (n = 35) and a waiting list group (control group) (n = 43) with

subsequent cognitive behavioural rehabilitation (CBR) for all participants in both groups. The

recovery from ED was compared between the forest rehabilitation and the control group at

baseline, after the forest rehabilitation (3 months), and at the end of the CBR (1 year). Both

groups had enhanced recovery from ED after the 3-month intervention period and at the end of

the CBR (1 year), and there were no significant differences between the groups in terms of

psychological health measures. Mental state, attention capacity and preferences for different

forest environments were studied during the forest visits. Mental state was improved, but it

showed some seasonal differences. A significant effect on attention capacity was found for single

forest visits, but there was no effect found for the rehabilitation period as a whole. The most

popular forest environments contained easily accessible, open and bright settings with visible

water and/or shelter. Forest rehabilitation did not enhance the recovery from ED compared to the

control group, but the participants' well-being was improved after single forest visits.

Song, C., et al. (2015). "Elucidation of a physiological adjustment effect in a forest

environment: A pilot study." International Journal of Environmental Research and Public

Health 12(4): 4247-4255.

There is a significant positive relationship between exposure to forest environments and

physical and mental health. However, there are individual differences within these responses,

and this phenomenon has posed questions in various fields. Here, we show that the physiological

effect of a forest environment can differ depending on a subject’s initial values and that forests

have a physiological adjustment effect close to an appropriate level. Subjects with high initial

blood pressure and pulse rate showed a decrease in these values after walking in a forested area,

whereas those with low initial values showed an increase. There was no physiological adjustment

effect observed in an urban area; thus, these effects are specific to a forest environment.

Siņicina, N., et al. (2015). "Amount of Air Ions Depending on Indoor Plant Activity."

Environment. Technology. Resources. Proceedings of the International Scientific and

Practical Conference 2: 267.

Literature sources and earlier researches state that plants may be able to produce a variety

of air ions, including negative light ions. In this article, the regularity of influence of plants on

the number of ions in the room is being proved, basing on a series of experiments performed

with the following plants: Spathiphyllum, Scindapsus, Strobilanthes, Chlorophytum and Pinus

mugo. It was concluded that plants, in general, are able to stabilize the indoor ion concentration

and reduce its fluctuations. The plants help to increase the concentrations of negative ions and

decrease the concentration of positive ones, however the optimal and “healthy” ion concentration

was not reached. Plants without artificial illumination work more as ion reducers, not producers.

Sgrigna, G., et al. (2015). "Particulate Matter deposition on Quercus ilex leaves in an

industrial city of central Italy." Environmental Pollution 197: 187-194.

A number of studies have focused on urban trees to understand their mitigation capacity

of air pollution. In this study particulate matter (PM) deposition on Quercus ilex leaves was

quantitatively analyzed in four districts of the City of Terni (Italy) for three periods of the year.

Fine (between 0.2 and 2.5 μm) and Large (between 2.5 and 10 μm) PM fractions were analyzed.

Mean PM deposition value on Quercus ilex leaves was 20.6 μg cm−2. Variations in PM

deposition correlated with distance to main roads and downwind position relatively to industrial

area. Epicuticular waxes were measured and related to accumulated PM. For Fine PM deposited

in waxes we observed a higher value (40% of total Fine PM) than Large PM (4% of total Large

PM). Results from this study allow to increase our understanding about air pollution interactions

with urban vegetation and could be hopefully taken into account when guidelines for local urban

green management are realized.

Parmar, R. N., et al. (2015). "Assessment of Status and Carbon Sequestration Potential of

Green Cover in the Major Urban Development Authorities of Gujarat." Innovative Energy

Technology Systems and Environmental Concerns. A Sustainable Approach: 197-206.

Urban forest and tree cover play a fundamentally important role in improving the

environmental quality, energy efficiency, aesthetic appeal, biodiversity, and regulating the

climatic hazards. The study area encompasses the 8 major urban development authorities of

Gujarat which has observed a population increase from 0.59 crore in 1981 to 1.66 crore in 2011,

which is projected to increase to 2.01 crores as of 2021. The per capita CO2 emission was

recorded to be 1.6 tons/annum in 2011 and is expected to rise to 2-2.5 tons/annum by 2021. The

average rate of conversion of land in Gujarat for non-agricultural and non-forestry uses is about

4,000 ha per year leading to the severe defacement of the green cover. In this study, an

assessment and evaluation of the area under the urban forest & tree cover and its respective

carbon sequestration potential is done for the base year (2011) and an attempt is being made to

calculate it for the year 2021 using the standard protocols. As of 2011, about 64.31 lakh trees of

about 230 species above 10 cm girth at breast height was enumerated in the study area. The study

highlights that the green cover inclusive city planning, stakeholder’s coordination, use of native

tree species, compensatory afforestation mechanism, protection of the existing green areas, and

employment generation through GIM and MNERGA schemes in the social and agro forestry

plantations can enhance the overall green cover in the urban agglomerations of Gujarat. As a

result, the total tree number in the study area can be increased from 64.13 lakhs (2011) to 143.7

lakhs (2021) and the carbon stock can be enhanced from 12.86 lakh tonnes of carbon in 2011 to

28.74 lakh tonnes till 2021. For achieving the desired targets, the land under the plantation has to

be increased from 23,760 ha in 2011 to 55,158 ha till 2021. Hence, enhancing urban tree and

forest cover can give plausible solutions to the infinite woes of socio-economic, ecological, and

environmental sustainability of the urban areas of Gujarat.

Pakzad, P., et al. (2015). Review of tools for quantifying the contribution of green

infrastructure to carbon performance. Proc. ICUC9-9th International Conference on

Urban Climate jointly with 12th Symposium on the Urban Environment, Toulouse.

The exchange of carbon between the atmosphere and biosphere is an important factor in

global climate regulation. Consequently, it is important to examine how carbon flows and cycles

between different pools and how carbon stocks change in response to afforestation, reforestation,

deforestation, and other land-cover and land-use activities.

Eco-cities and green-cities are emerging concepts for the retrofitting of our urban areas and

important component in the creation of more sustainable development towards climate change

adaptation and mitigation. Green infrastructure as a key part of eco-cities and green-cities

contributes as a major carbon pool for. The term ‘green infrastructure’ refers to an

interconnected network of landscape assets that are intertwined with engineered (grey)

infrastructure and buildings.

The ability to assess the performance of green infrastructure, based on measurable criteria

at a variety of temporal and spatial scales, is critical for defining the difference between effective

and non-effective scenarios for sustainable urban development.

This paper aims to identify the most relevant and applicable evaluation tools, applications and

methods for quantifying the carbon performance of green infrastructure in Australia.

The existing quantitative tools used to measure green infrastructure sustainability performance

are varied in terms of the scale, components and input. This study has identified and tabulated

the most relevant tools for quantifying the features and carbon services of green infrastructure.

The aim is to help policymakers, environmental groups and researchers to choose the most

appropriate tool(s) for the intended context and it will lead them to a more useful and accurate

carbon foot printing assessment outcome.

Önder, S. and A. Akay (2015). "Reduction of Traffic Noise Pollution Effects by Using

Vegetation." Journal of Engineering and Economic Development 2(2): 23.

It is a well-known fact in all societies worldwide that noise is a serious environmental

pollutant. In this paper, negative effects resulting from exposure to noise pollution on people’s

well-being is reviewed in the light of the previous published studies. First, noise is generally

defined, subsequently, in order to clarify the subject, noise pollution types, negative effects of

noise on human’s health and attenuation methods of noise pollution are discussed. In conclusion

previous studies about the topic of ‘the mitigation of the noise pollution effects by using

vegetation’ in Turkey are reviewed to explain the reduction methods of the noise pollution by

vegetation and to refer to its aesthetical, ecological, etc. advantages, excluding its noise barrier

function. Considering the negative effects of the noise pollution, the findings of this study are

important at both individual and social level and could be helpful as a guidance for planning of

the areas which have the potential of the noise pollution effects.

Norton, B. A., et al. (2015). "Planning for cooler cities: A framework to prioritise green

infrastructure to mitigate high temperatures in urban landscapes." Landscape and Urban

Planning 134: 127-138.

Warming associated with urban development will be exacerbated in future years by

temperature increases due to climate change. The strategic implementation of urban green

infrastructure (UGI) e.g. street trees, parks, green roofs and facades can help achieve temperature

reductions in urban areas while delivering diverse additional benefits such as pollution reduction

and biodiversity habitat. Although the greatest thermal benefits of UGI are achieved in climates

with hot, dry summers, there is comparatively little information available for land managers to

determine an appropriate strategy for UGI implementation under these climatic conditions. We

present a framework for prioritisation and selection of UGI for cooling. The framework is

supported by a review of the scientific literature examining the relationships between urban

geometry, UGI and temperature mitigation which we used to develop guidelines for UGI

implementation that maximises urban surface temperature cooling. We focus particularly on

quantifying the cooling benefits of four types of UGI: green open spaces (primarily public

parks), shade trees, green roofs, and vertical greening systems (green walls and facades) and

demonstrate how the framework can be applied using a case study from Melbourne, Australia.

Nasiri, M., et al. (2015). "The Effects of tree species on reduction of the rate of noise

pollution at the edge of Hyrcanian forest roads." Environ Eng Manag J 14(5): 1021-1026.

Plants have an effective role in reducing noise pollution. The aim of this study was to

evaluate the impact of broad-leaved and coniferous species on reducing noise pollution

according to the distance from the sound source and the tree species type. For this purpose, 25

plots for coniferous species and 25 plots for the broadleaved species was selected. The decibel-

meter (Casella Enhances CEL-630) and the trumpet (FIAMM) of machine were used to measure

the sound level. Results indicated that the tree at the edge of the forest roads causes to decrease

noise pollution. As, there was a significant difference between the distance of 300 meter as

compared with the distances of 20 meter and 100 meter for the broadleaved species (P<0.05).

We also found an inverse relationship between frequency of broadleaved and coniferous trees

and the rate of sound level (R2 = 0.94 for coniferous; R2 = 0.89 for hardwood). In plots consist

of broadleaved species, the sound level at the distances of 20, 100 and 300 meter have been

reduced 10.6, 14.5 and 19.4 dB, respectively. This difference with considering these distances

was respectively 10.4, 14.3 and 16.8 dB for coniferous species. It is suggested that the species

with low H:D ratio (Height of tree: DBH) and wide crown used to decrease noise pollution. The

coniferous species which is grown dense can be used to provide aesthetic quality and increase

number of stories.

Mullaney, J., et al. (2015). "A review of benefits and challenges in growing street trees in

paved urban environments." Landscape and Urban Planning 134(0): 157-166.

Street trees are an integral element of urban life. They provide a vast range of benefits in

residential and commercial precincts, and they support healthy communities by providing

environmental, economic and social benefits. However, increasing areas of impermeable surface

can increase the stresses placed upon urban ecosystems and urban forests. These stresses often

lead tree roots to proliferate in sites that provide more-favourable conditions for growth, but

where they cause infrastructure damage and pavement uplift. This damage is costly and a variety

of preventative measures has been tested to sustain tree health and reduce pavement damage.

This review explores a wide range of literature spanning 30 years that demonstrates the benefits

provided by street trees, the perceptions of street trees conveyed by urban residents, the costs of

pavement damage by tree roots, and some tried and tested measures for preventing pavement

damage and improving tree growth.

Middel, A., et al. (2015). "Urban forestry and cool roofs: Assessment of heat mitigation

strategies in Phoenix residential neighborhoods." Urban Forestry & Urban Greening

14(1): 178-186.

The City of Phoenix (Arizona, USA) developed a Tree and Shade Master Plan and a Cool

Roofs initiative to ameliorate extreme heat during the summer months in their arid city. This

study investigates the impact of the City's heat mitigation strategies on daytime microclimate for

a pre-monsoon summer day under current climate conditions and two climate change scenarios.

We assessed the cooling effect of trees and cool roofs in a Phoenix residential neighborhood

using the microclimate model ENVI-met. First, using xeric landscaping as a base, we created

eight tree planting scenarios (from 0% canopy cover to 30% canopy cover) for the neighborhood

to characterize the relationship between canopy cover and daytime cooling benefit of trees. In a

second set of simulations, we ran ENVI-met for nine combined tree planting and landscaping

scenarios (mesic, oasis, and xeric) with regular roofs and cool roofs under current climate

conditions and two climate change projections. For each of the 54 scenarios, we compared

average neighborhood mid-afternoon air temperatures and assessed the benefits of each heat

mitigation measure under current and projected climate conditions. Findings suggest that the

relationship between percent canopy cover and air temperature reduction is linear, with 0.14 °C

cooling per percent increase in tree cover for the neighborhood under investigation. An increase

in tree canopy cover from the current 10% to a targeted 25% resulted in an average daytime

cooling benefit of up to 2.0 °C in residential neighborhoods at the local scale. Cool roofs reduced

neighborhood air temperatures by 0.3 °C when implemented on residential homes. The results

from this city-specific mitigation project will inform messaging campaigns aimed at engaging

the city decision makers, industry, and the public in the green building and urban forestry

initiatives.

Mahnert, A., et al. (2015). "Microbiome interplay: plants alter microbial abundance and

diversity within the built environment." Frontiers in Microbiology 6(887).

The built indoor microbiome has importance for human health. Residents leave their

microbial fingerprint but nothing is known about the transfer from plants. Our hypothesis that

indoor plants contribute substantially to the microbial abundance and diversity in the built

environment was experimentally confirmed as proof of principle by analyzing the microbiome of

the spider plant Chlorophytum comosum in relation to their surroundings. The abundance of

Archaea, Bacteria and Eukaryota (fungi) increased on surrounding floor and wall surfaces within

six months of plant isolation in a cleaned indoor environment, whereas the microbial abundance

on plant leaves and indoor air remained stable. We observed a microbiome shift: the bacterial

diversity on surfaces increased significantly but fungal diversity decreased. The majority of cells

were intact at the time of samplings and thus most probably alive including diverse Archaea as

yet unknown phyllosphere inhabitants. LEfSe and network analysis showed that most microbes

were dispersed from plant leaves to the surrounding surfaces. This led to an increase of specific

taxa including spore-forming fungi with potential allergic potential but also beneficial plant-

associated bacteria, e.g. Paenibacillus. This study demonstrates for the first time that plants can

alter the microbiome of a built environment, which supports the significance of plants and

provides insights into the complex interplay of plants, microbiomes and human beings.

Luederitz, C., et al. (2015). "A review of urban ecosystem services: six key challenges for

future research." Ecosystem Services 14: 98-112.

Global urbanization creates opportunities and challenges for human well-being and

transition towards sustainability. Urban areas are human-environment systems that depend

fundamentally on ecosystems, and thus require an understanding of the management of urban

ecosystem services to ensure sustainable urban planning. The purpose of this study is to provide

a systematic review of urban ecosystems services research, which addresses the combined

domain of ecosystem services and urban development. We examined emerging trends and gaps

in how urban ecosystem services are conceptualized in peer-reviewed case study literature,

including the geographical distribution of research, the development and use of the urban

ecosystem services concept, and the involvement of stakeholders. We highlight six challenges

aimed at strengthening the concept's potential to facilitate meaningful inter- and transdisciplinary

work for ecosystem services research and planning. Achieving a cohesive conceptual approach

in the research field will address (i) the need for more extensive spatial and contextual coverage,

(ii) continual clarification of definitions, (iii) recognition of limited data transferability, (iv) more

comprehensive stakeholder involvement, (v) more integrated research efforts, and (vi) translation

of scientific findings into actionable knowledge, feeding information back into planning and

management. We conclude with recommendations for conducting further research while

incorporating these challenges.

Lin, W., et al. (2015). "Calculating cooling extents of green parks using remote sensing:

Method and test." Landscape and Urban Planning 134: 66-75.

A green park can be an effective contributor to the reduction of higher temperatures

caused by urban heat island effects. A park's cooling effect extends beyond its boundary into the

surrounding streets and buildings. Up to now, the measurement of the extent of the cooling effect

beyond the park has relied mainly on on-site observations. An alternative method is to calculate

the extent of cooling using remote sensing. The principle of the method is that the cooling effect

will decline from the boundary into the surrounding areas to a distance at which the effect is

longer felt. Analysis of Landsat TM/ETM+ images of Beijing revealed that cooling effects

extend as much as 840 m away from the park in cone case, but as little as 35 m in another. While

related in part to park size, the extent of the cooling effect is also influenced by the character of

the area around each park. Remote sensing provides a viable alternative to ground temperature

measurements, but attention has to be paid to the actual cityscape and characteristics of each park

as well as to the resolution of the imagery.

Kronenberg, J. (2015). "Why not to green a city? Institutional barriers to preserving urban

ecosystem services." Ecosystem Services 12: 218-227.

This article investigates the institutional context of urban greening, with a particular

focus on institutional failures that hinder urban ecosystems׳ capacity to provide urban inhabitants

with services. It is based on a literature review and a study of expert opinions carried out in

Poland (with 103 experts involved in the management of urban trees as respondents). The

institutional failures covered by this article include government and social empowerment

failures. The most important government failures include insufficient funds and various problems

related to unprofessional maintenance of trees and its supervision. The most important social

empowerment failures include lack of mobilization, related to under-appreciation of the

importance of trees and disservices related to trees. While the current discourse on ecosystem

services focuses on raising awareness of the benefits that nature provides, this study

demonstrates that protecting urban ecosystems׳ capacity to provide us with such services requires

a broad institutional reform. This need is particularly relevant in post-socialist, post-transition

countries, such as Poland.

Ko, Y., et al. (2015). "Long-term monitoring of Sacramento Shade program trees: Tree

survival, growth and energy-saving performance." Landscape and Urban Planning 143:

183-191.

Long-term survival and growth of urban forests are critical to achieve the targeted

benefits of urban tree planting programs, such as building energy savings from tree shade.

However, little is known about how trees perform in the long-term, especially in residential

areas. Given this gap in the literature, we monitored 22-years of post-planting survival, growth,

and energy saving performance of shade trees in Sacramento, California. Using field surveys,

aerial photo interpretation and survival analysis, we calculated cumulative survivorship and

compared measured with projected tree growth. Using Shadow Pattern Simulator and Micropas

(building energy simulation), combined with survival and growth observations, we modeled the

current energy savings produced by the program trees and then compared this result with initial

projections from the early years of the program. The 22-year post planting survivorship was

42.4%, considerably less than the initial projection. On average, measured growth rates were

within expected ranges to provide shading benefits; 22-year old trees reached 74.6% and 68.8%

of the projected 30-year mature size for tree heights and crown diameters, respectively. Annual

energy savings were 107 kW h per property and 80 kW h per tree, which were 23% and 52% of

the initial projection, respectively. Lower survivorship was the primary factor influencing lower

cooling savings. Medium-sized trees had higher survivorship and growth attainment compared to

other trees. This study contributes to more accurate quantification of urban greening

performance, helping urban forest managers make data-driven decisions.

Janhäll, S. (2015). "Review on urban vegetation and particle air pollution – Deposition and

dispersion." Atmospheric Environment 105: 130-137.

Urban vegetation affects air quality through influencing pollutant deposition and

dispersion. Both processes are described by many existing models and experiments, on-site and

in wind tunnels, focusing e.g. on urban street canyons and crossings or vegetation barriers

adjacent to traffic sources. There is an urgent need for well-structured experimental data,

including detailed empirical descriptions of parameters that are not the explicit focus of the

study. This review revealed that design and choice of urban vegetation is crucial when using

vegetation as an ecosystem service for air quality improvements. The reduced mixing in

trafficked street canyons on adding large trees increases local air pollution levels, while low

vegetation close to sources can improve air quality by increasing deposition. Filtration vegetation

barriers have to be dense enough to offer large deposition surface area and porous enough to

allow penetration, instead of deflection of the air stream above the barrier. The choice between

tall or short and dense or sparse vegetation determines the effect on air pollution from different

sources and different particle sizes.

James Barth, B., et al. (2015). "New urban developments that retain more remnant trees

have greater bird diversity." Landscape and Urban Planning 136: 122-129.

The rapid expansion of urban landscapes has significant consequences for wildlife.

Habitat loss and fragmentation cause significant loss of species richness. While remnant

fragments of habitat are important areas for conservation, the urban matrix between fragments is

also critical. Increasing the suitability of the matrix for wildlife can increase the diversity of

wildlife that utilise urban landscapes and increases the potential for dispersal among fragments.

We investigated the effectiveness of retaining remnant trees during for increasing the species

richness and abundance of birds in new urban housing developments. We measured species

richness and abundance in four habitat types: non-vegetated streets, vegetated streets,

recreational parks and bush sites. We discovered that the number of bird species observed was

lowest on the non-vegetated streets and highest within the bush fragments. Species richness on

vegetated streets was intermediate between non-vegetated streets and parks. The abundance of

birds was highest within recreational parks and we observed significantly more birds on

vegetated streets than non-vegetated streets. Additionally, we found the number of species and

total abundance of birds was positively associated with the total number of retained mature trees

within a vegetated street. The dominant feeding guild and species composition varied between

the different habitat types. Our findings suggest that increasing the number of retained mature

trees in new housing developments may be an effective means of increasing the number of bird

species that utilise the urban matrix.

Irga, P. J., et al. (2015). "Does urban forestry have a quantitative effect on ambient air

quality in an urban environment?" Atmospheric Environment 120: 173-181.

Increasing urban greenspace has been proposed as a means of reducing airborne pollutant

concentrations; however limited studies provide experimental data, as opposed to model

estimates, of its ability to do so. The current project examined whether higher concentrations of

urban forestry might be associated with quantifiable effects on ambient air pollutant levels,

whilst accounting for the predominant source of localized spatial variations in pollutant

concentrations, namely vehicular traffic. Monthly air samples for one year were taken from

eleven sites in central Sydney, Australia. The sample sites exhibited a range of different traffic

density, population usage, and greenspace/urban forest density conditions. Carbon dioxide

(CO2), carbon monoxide (CO), total volatile organic compounds (TVOCs), nitric oxide (NO),

nitrogen dioxide (NO2), sulfur dioxide (SO2), total suspended particulate matter (TSP),

suspended particles <10 μm in diameter (PM10) and particulate matter <2.5 μm (PM2.5), were

recorded, using portable devices. It was found that air samples taken from sites with less

greenspace frequently had high concentrations of all fractions of aerosolized particulates than

other sites, whilst sites with high proximal greenspace had lower particulates, even when

vehicular traffic was taken into account. No observable trends in concentrations of NO, TVOC

and SO2 were observed, as recorded levels were generally very low across all sampled areas.

The findings indicate, first, that within the urban areas of a city, localized differences in air

pollutant loads occur. Secondly, we conclude that urban areas with proportionally higher

concentrations of urban forestry may experience better air quality with regards to reduced

ambient particulate matter; however conclusions about other air pollutants are yet to be

elucidated.

Heaviside, C., et al. (2015). "The effects of horizontal advection on the urban heat island in

Birmingham and the West Midlands, United Kingdom during a heatwave." Q J Roy

Meteorol Soc 141.

Birmingham is the second most populous city in the United Kingdom and observations

indicate that it has a pronounced urban heat island (UHI), i.e. higher ambient temperatures in the

city centre compared with surrounding suburban and rural areas, particularly at night. The effects

of UHIs are often amplified during anticyclonic summer weather conditions, which can cause or

exacerbate heatwaves. Enhanced temperatures in highly populated regions can mean that

significant numbers of people are at risk from heat-related illness during hot weather. Climate

change projections often do not include the effects of the UHI, which can mean that assessments

of heat-related health effects using these projections underestimate the actual magnitude of future

health impacts. We present numerical simulations of the UHI in Birmingham and the West

Midlands Metropolitan region during the heatwave of August 2003 using the high-resolution,

regional meteorological Weather Research and Forecasting (WRF) model, with an urban canopy

scheme. We evaluated the model using local air-temperature observations, and found good

model performance in capturing the temporal and spatial signature of the UHI. We performed a

sensitivity test, replacing urban land categories with rural ones, and found that the difference in

temperature between the two model runs throughout the heatwave period (2–11 August 2003)

was around 3°C on average, and reached a maximum of 7°C. Finally, we present a novel generic

methodology to enable the examination of the extent of horizontal advection of warm air

downwind of the conurbation area. We found that during the heatwave, temperatures downwind

of Birmingham were up to 2.5°C warmer than those upwind. This methodology has the potential

for improvements to, or parametrizations for, diagnostic models that do not explicitly include

dynamics and where local conditions are driven largely by land-surface type.

Hashemi, S. S. G., et al. (2015). "Performance of green roofs with respect to water quality

and reduction of energy consumption in tropics: A review." Renewable and Sustainable

Energy Reviews 52: 669-679.

Green roofs are an increasingly important component of water-sensitive urban design

systems that can potentially improve the quality of urban runoff, reduce the energy consumption

of buildings, and add esthetic value to the environment. The most important green roof abilities,

which appear as a key feature in urban catchments are the ability of rainwater detention and

retention and reduction in energy consumption. This paper aims to provide an overview of the

effects of the application of the green roof strategy on the quality of runoff water and the

reduction of energy consumption. The components of a green roof are discussed, and the

advantages and disadvantages of different types of green roofs are assessed. In addition, the

origins and concentrations of the main pollutants are discussed, moreover environmental cost-

benefits of green roofs are also considered. In addition, the main factors that affect the quality of

green roof runoff water, e.g., plant species, fertilization, pH, growth media as well as how green

roofs could reduce energy consumption are discussed. Green roofs are considered as sustainable

approach for runoff management with achieved aesthetical values and in combination with

energy saving on heating/cooling. Hence, green roof causes a sufficient decrease in energy

consumption and consequently in the related energy costs. It can help to improve the micro

climate around the buildings and save money and also improve water quality. Therefore, green

roofs may turn into a profitable investment. Some recommendations for future study also are

proposed.

Hansen, R., et al. (2015). "The uptake of the ecosystem services concept in planning

discourses of European and American cities." Ecosystem Serv 12.

Ecosystem services (ES) are gaining increasing attention as a promising concept to more

actively consider and plan for the varied benefits of the urban environment. Yet, to have an

impact on decision- making, the concept must spread from academia to practice. To understand

how ES have been taken up in planning discourses we conducted a cross-case comparison of

planning documents in Berlin, New York, Salzburg, Seattle and Stockholm. We found: (1)

explicit references to the ES concept were primarily in documents from Stockholm and New

York, two cities in countries that entered into ES discourses early. (2) Implicit references and

thus potential linkages between the ES concept and planning discourses were found frequently

among all cities, especially in Seattle. (3) The thematic scope, represented by 21 different ES, is

comparably broad among the cases, while cultural services and habitat provision are most

frequently emphasized. (4) High-level policies were shown to promote the adoption of the ES

concept in planning. We find that the ES concept holds potential to strengthen a holistic

consideration of urban nature and its benefits in planning. We also revealed potential for further

development of ES approaches with regard to mitigation of environmental impacts and

improving urban resilience.

Gromke, C. and B. Blocken (2015). "Influence of avenue-trees on air quality at the urban

neighborhood scale. Part II: Traffic pollutant concentrations at pedestrian level." Environ

Pollut 196.

Flow and dispersion of traffic‐emitted pollutants were studied in a generic urban

neighborhood for various avenue‐tree layouts by employing 3D steady RANS simulations with

the realizable k‐ε turbulence model. In comparison to the tree‐free situation quantitative and

qualitative changes with flow reversal in the wind field were observed. Low to moderate

increases (<13.2%) in the neighborhood‐averaged pollutant concentration were found at

pedestrian level. An approximately 1% increase in the neighborhood‐averaged concentration was

obtained with each percent of the street canyon volumes being occupied by vegetation for

occupation fractions between 4 and 14%. The overall pattern of concentration changes relative to

the tree‐free situation was similar for all avenue‐tree layouts. However, pronounced locally

restricted decreases or increases in concentration (‐87 to +1378%) occurred. The results indicate

the necessity to account for existing or planned avenue‐trees in neighborhood scale dispersion

studies. Their consideration is prerequisite for reliable urban air quality assessment.

Gorzelak, M. A., et al. (2015). "Inter-plant communication through mycorrhizal networks

mediates complex adaptive behaviour in plant communities." AoB Plants 7.

Adaptive behaviour of plants, including rapid changes in physiology, gene regulation and

defence response, can be altered when linked to neighbouring plants by a mycorrhizal network

(MN). Mechanisms underlying the behavioural changes include mycorrhizal fungal colonization

by the MN or interplant communication via transfer of nutrients, defence signals or

allelochemicals. We focus this review on our new findings in ectomycorrhizal ecosystems, and

also review recent advances in arbuscular mycorrhizal systems. We have found that the

behavioural changes in ectomycorrhizal plants depend on environmental cues, the identity of the

plant neighbour and the characteristics of the MN. The hierarchical integration of this

phenomenon with other biological networks at broader scales in forest ecosystems, and the

consequences we have observed when it is interrupted, indicate that underground 'tree talk' is a

foundational process in the complex adaptive nature of forest ecosystems.

Gasparrini, A., et al. (2015). "Mortality risk attributable to high and low ambient

temperature: a multicountry observational study." Lancet 386.

Background Although studies have provided estimates of premature deaths attributable to

either heat or cold in selected countries, none has so far offered a systematic assessment across

the whole temperature range in populations exposed to different climates. We aimed to quantify

the total mortality burden attributable to non-optimum ambient temperature, and the relative

contributions from heat and cold and from moderate and extreme temperatures.

Methods We collected data for 384 locations in Australia, Brazil, Canada, China, Italy, Japan,

South Korea, Spain, Sweden, Taiwan, Thailand, UK, and USA. We fitted a standard time-series

Poisson model for each location, controlling for trends and day of the week. We estimated

temperature–mortality associations with a distributed lag non-linear model with 21 days of lag,

and then pooled them in a multivariate metaregression that included country indicators and

temperature average and range. We calculated attributable deaths for heat and cold, defined as

temperatures above and below the optimum temperature, which corresponded to the point of

minimum mortality, and for moderate and extreme temperatures, defined using cutoffs at the

2·5th and 97·5th temperature percentiles.

Findings We analysed 74 225 200 deaths in various periods between 1985 and 2012. In

total, 7·71% (95% empirical CI 7·43–7·91) of mortality was attributable to non-optimum

temperature in the selected countries within the study period, with substantial differences

between countries, ranging from 3·37% (3·06 to 3·63) in Thailand to 11·00% (9·29 to 12·47) in

China. The temperature percentile of minimum mortality varied from roughly the 60th percentile

in tropical areas to about the 80–90th percentile in temperate regions. More temperature-

attributable deaths were caused by cold (7·29%, 7·02–7·49) than by heat (0·42%, 0·39–0·44).

Extreme cold and hot temperatures were responsible for 0·86% (0·84–0·87) of total mortality.

Interpretation Most of the temperature-related mortality burden was attributable to the

contribution of cold. The effect of days of extreme temperature was substantially less than that

attributable to milder but non-optimum weather. This evidence has important implications for the

planning of public-health interventions to minimise the health consequences of adverse

temperatures, and for predictions of future effect in climate-change scenarios.

Gallagher, J., et al. (2015). "Passive methods for improving air quality in the built

environment: A review of porous and solid barriers." Atmospheric Environment 120: 61-

70.

Protecting the health of growing urban populations from air pollution remains a challenge

for planners and requires detailed understanding of air flow and pollutant transport in the built

environment. In recent years, the work undertaken on passive methods of reducing air pollution

has been examined to address the question: “how can the built environment work to alter natural

dispersion patterns to improve air quality for nearby populations?” This review brings together a

collective of methods that have demonstrated an ability to influence air flow patterns to reduce

personal exposure in the built environment. A number of passive methods exists but, in the

context of this paper, are split into two distinct categories: porous and solid barriers. These

methods include trees and vegetation (porous) as well as noise barriers, low boundary walls and

parked cars (solid); all of which have gained different levels of research momentum over the past

decade. Experimental and modelling studies have provided an understanding of the potential for

these barriers to improve air quality under varying urban geometrical and meteorological

conditions. However, differences in results between these studies and real-world measurements

demonstrate the challenges and complexities of simulating pollutant transport in urban areas.

These methods provide additional benefits to improving air quality through altering dispersion

patterns; avenue trees and vegetation are aesthetically pleasing and provides cooling and shade

from direct sunlight. Additionally, real-world case studies are considered an important direction

for further verification of these methods in the built environment. Developing design guidelines

is an important next stage in promoting passive methods for reducing air pollution and ensuring

their integration into future urban planning strategies. In addition, developing channels of

communication with urban planners will enhance the development and uptake of design

guidelines to improve air quality in the built environment.

Fantozzi, F., et al. (2015). "Spatio-temporal variations of ozone and nitrogen dioxide

concentrations under urban trees and in a nearby open area." Urban Climate 12.

The evergreen Quercus ilex L. is one of the most common trees in Italian urban

environments and is considered effective in the uptake of particulate and gaseous atmospheric

pollutants. Howev- er, the few available estimates on O3 and NO2 removal by urban Q. ilex

originate from model-based studies (which indicate NO2/O3 removal capacity of Q. ilex) and not

from direct measurements of air pollutant concentrations. Thus, in the urban area of Siena (cen-

tral Italy) we began long-term monitoring of O3/NO2 concentrations using passive samplers at a

distance of 1, 5, 10 m from a busy road, under the canopies of Q. ilex and in a nearby open-field.

Measure- ments performed in the period June 2011–October 2013 showed always a greater

decrease of NO2 concentrations under the Q. ilex canopy than in the open-field transect.

Conversely, a decrease of average O3 concentrations under the tree canopy was found only in

autumn after the typical Mediterranean post-summer rainfalls. Our results indicate that

interactions between O3/NO2 concentra- tions and trees in Mediterranean urban ecosystems are

affected by temporal variations in climatic conditions. We argue therefore that the direct

measurement of atmospheric pollutant concentra- tions should be chosen to describe local

changes of aerial pollution.

Fan, C., et al. (2015). "Measuring the spatial arrangement of urban vegetation and its

impacts on seasonal surface temperatures." Progress in Physical Geography 39(2): 199-

219.

Urban forestry is an important component of the urban ecosystem that can effectively

ameliorate temperatures by providing shade and through evapotranspiration. While it is well

known that vegetation abundance is negatively correlated to land surface temperature, the

impacts of the spatial arrangement (e.g. clustered or dispersed) of vegetation cover on the urban

thermal environment requires further investigation. In this study, we coupled remote sensing

techniques with spatial statistics to quantify the configuration of vegetation cover and its variable

influences on seasonal surface temperatures in central Phoenix. The objectives of this study are

to: (1) determine spatial arrangement of green vegetation cover using continuous spatial

autocorrelation indices combined with high-resolution remotely-sensed data; (2) examine the

role of grass and trees, especially their spatial patterns on seasonal and diurnal land surface

temperatures by controlling the effects of vegetation abundance; (3) investigate the sensitivity of

the vegetation–temperature relationship at varying geographical scales. The spatial pattern of

urban vegetation was measured using a local spatial autocorrelation index—the local Moran’s Iv.

Results show that clustered or less fragmented patterns of green vegetation lower surface

temperature more effectively than dispersed patterns. The relationships between the local

Moran’s Iv and surface temperature are evidenced to be strongest during summer daytime and

lowest during winter nighttime. Results of multiple regression analyses demonstrate significant

impacts of spatial arrangement of vegetation on seasonal surface temperatures. Our analyses of

vegetation spatial patterns at varying geographical scales suggest that an area extent of ˜200 m is

optimal for examining the vegetation–temperature relationship. We provide a methodological

framework to quantify the spatial pattern of urban features and to examine their impacts on the

biophysical characteristics of the urban environment. The insights gained from our study results

have significant implications for sustainable urban development and resource management.

Derkzen, M. L., et al. (2015). "REVIEW: Quantifying urban ecosystem services based on

high‐resolution data of urban green space: an assessment for Rotterdam, the Netherlands."

Journal of Applied Ecology 52(4): 1020-1032.

The urban dimension of ecosystem services (ES) is underexposed, while the importance

of ES for human well-being is nowhere as evident as in cities. Urban challenges such as air pol-

lution, noise and heat can be moderated by urban green space (UGS), simultaneously provid- ing

multiple other services. However, available methods to quantify ES cannot typically deal with

the high spatial and thematic resolution land cover data that are needed to better under- stand ES

supply in the urban context.

This study derives methods to quantify and map a bundle of six ES as supplied by UGS,

using land cover data with high spatial and thematic resolution, and applies these to the city of

Rotterdam, the Netherlands. Land cover data comprise eight classes of UGS. Methods are

derived from an evidence base on the importance of UGS types for the supply of each of the six

ES that was built using literature review.

The evidence base reveals that UGS types differ in their contribution to various ES,

although the strength of the evidence varies. However, existing indicators for urban ES often do

not discriminate between UGS types. To derive UGS-specific indicators, we combined methods

and evidence from different research contexts (ES, non-ES, urban, non-urban).

Rotterdam shows high spatial variation in the amount of UGS present, and accounting for

this in ES supply reveals that ES bundles depend on UGS composition and configuration. While

the contribution of UGS types to ES supply differed markedly with UGS type and ES

considered, we demonstrate that synergies rather than trade-offs exist among the ES analysed.

Synthesis and applications. Our findings underline the importance of a careful design of

urban green space (UGS) in city planning for ecosystem services (ES) provision. Based on the

latest insights on how different UGS provide ES, the methods presented in this study enable a

more detailed quantification and mapping of the supply of ES in cities, allowing assess- ments of

current supply of key urban ES and alternative urban designs. Such knowledge is indispensable

in the quest for designing healthier and climate-resilient cities.

Dadvand, P., et al. (2015). "The association between greenness and traffic-related air

pollution at schools." Science of The Total Environment 523: 59-63.

Greenness has been reported to improve mental and physical health. Reduction in

exposure to air pollution has been suggested to underlie the health benefits of greenness;

however, the available evidence on the mitigating effect of greenness on air pollution remains

limited and inconsistent. We investigated the association between greenness within and

surrounding school boundaries and monitored indoor and outdoor levels of traffic-related air

pollutants (TRAPs) including NO2, ultrafine particles, black carbon, and traffic-related PM2.5 at

39 schools across Barcelona, Spain, in 2012. TRAP levels at schools were measured twice

during two one-week campaigns separated by 6 months. Greenness within and surrounding

school boundaries was measured as the average of satellite-derived normalized difference

vegetation index (NDVI) within boundaries of school and a 50 m buffer around the school,

respectively. Mixed effects models were used to quantify the associations between school

greenness and TRAP levels, adjusted for relevant covariates. Higher greenness within and

surrounding school boundaries was consistently associated with lower indoor and outdoor TRAP

levels. Reduction in indoor TRAP levels was partly mediated by the reduction in outdoor TRAP

levels. We also observed some suggestions for stronger associations between school surrounding

greenness and outdoor TRAP levels for schools with higher number of trees around them. Our

observed reduction of TRAP levels at schools associated with school greenness can be of public

importance, considering the burden of health effects of exposure to TRAPs in schoolchildren.

Coutts AM, W. E., Tapper NJ, Beringer J, Livesley SJ (2015). Temperature and human

thermal comfort effects of street trees across three contrasting street canyon environments.

Theor Appl Climatol.

Urban street trees provide many environmental, social, and economic benefits for our

cities. This research explored the role of street trees in Melbourne, Australia, in cooling the urban

microclimate and improving human thermal comfort (HTC). Three east–west (E–W) oriented

streets were studied in two contrasting street canyon forms (deep and shallow) and between

contrasting tree canopy covers (high and low). These streets were instrumented with multiple

microclimate monitoring stations to continuously measure air temperature, humidity, solar

radiation, wind speed and mean radiant temperature so as to calculate the Universal Thermal

Climate Index (UTCI) from May 2011 to June 2013, focusing on summertime conditions and

heat events. Street trees supported average daytime cooling during heat events in the shallow

canyon by around 0.2 to 0.6 °C and up to 0.9 °C during mid-morning (9:00–10:00). Maximum

daytime cooling reached 1.5 °C in the shallow canyon. The influence of street tree canopies in

the deep canyon was masked by the shading effect of the tall buildings. Trees were very effective

at reducing daytime UTCI in summer largely through a reduction in mean radiant temperature

from shade, lowering thermal stress from very strong (UTCI > 38 °C) down to strong (UTCI > 32

°C). The influence of street trees on canyon air temperature and HTC was highly localized and

variable, depending on tree cover, geometry, and prevailing meteorological conditions. The

cooling benefit of street tree canopies increases as street canyon geometry shallows and

broadens. This should be recognized in the strategic placement, density of planting, and species

selection of street trees.

Churkina, G., et al. (2015). "Natural selection? Picking the right trees for urban greening."

Environmental Science & Policy 47: 12-17.

Fast-track programs to plant millions of trees in cities around the world aim at the

reduction of summer temperatures, increase carbon storage, storm water control, provision of

space for recreation, as well as poverty alleviation. Although these multiple benefits speak

positively for urban greening programs, the programs do not take into account the drastic

differences between urban and natural systems. Elevated temperatures together with

anthropogenic emissions of air and water pollutants distinguish the urban system. Although the

potential for emissions of volatile organic compounds from urban vegetation combined with

anthropogenic emissions to produce ozone has long been recognized, the municipalities actively

enlarging their green spaces still generally either overlook or ignore this fact. Here we assess the

scientific evidence of biogenic induction of ground-level ozone concentrations in urban and sub-

urban areas and argue that it is feasible and beneficial to implement measures necessary to limit

biogenic contributions to air pollution. With the example of biogenic induction of ground level

ozone concentrations we demonstrate that interactions between plants and urban ambient

conditions have to be taken into account in all efforts of creating “naturopolises”. We explore the

mechanisms behind these interactions and propose a pathway to improve our understanding of

these interactions.

Chen, W. Y. (2015). "The role of urban green infrastructure in offsetting carbon emissions

in 35 major Chinese cities: A nationwide estimate." Cities 44: 112-120.

The carbon balance in urban areas has become a major research challenge and a principal

policy concern in efforts to address anthropogenic climate change. Rapid urbanization and

industrialization in China urge the search for integrated strategies to mitigate and adapt to

climate change, which not only limit to traditional infrastructure sectors, but also cover urban

green infrastructure, because plants and soils function as carbon sinks through biotic

sequestration. This study presents a nationwide study about how urban green infrastructure could

contribute to the carbon balance in 35 major Chinese cities. By the end of 2010, the total area of

urban green spaces (the dominant components of urban green infrastructure) accounts for 6.38%

of the total land area of these cities and represented 51.7% of the total urban green spaces of all

657 cities in China. Based on empirical data from the literature, the total amount of carbon stored

in the vegetation of the urban green infrastructure of 35 cities was estimated at 18.7 million tons,

with an average carbon density of 21.34 t/ha. In 2010, the amount of carbon sequestration totaled

1.90 million tons with an average carbon sequestration rate of 2.16 t/ha/year. Collectively, only

0.33% of the carbon emissions from fossil fuel combustion can be offset, ranging from 0.01% in

Hohhot to 22.45% in Haikou. Nevertheless, the dominance of young vegetation stands in

Chinese urban green infrastructure suggests this small carbon sequestration efficiency could

become substantial in the near future, given that appropriate policies and management practices

are adopted to promote urban green infrastructure for climate change mitigation and adaptation.

Caruso, G., et al. (2015). "Greener and larger neighbourhoods make cities more

sustainable! A 2D urban economics perspective." Computers, Environment and Urban

Systems 54: 82-94.

We analyse urban growth forms by means of a 2D microeconomic model where

households value green space at neighbourhood scale. We analytically demonstrate that cities

can grow more densely when households have the possibility to enlarge the neighbourhood in

which they value green space, thus emphasizing the importance of neighbourhood planning in

particular for facilitating short trips and views of green amenities. We also show by simulation

that the size and form of the city, relative to the size and form of neighbourhoods, impact on the

decision of households to leapfrog land or not, thus impacting on the emergence of scattered

urbanisation patterns. We conclude that carefully addressing the spatial arrangement of green

space and buildings and facilitating trips within neighbourhood units constitute an effective

policy lever and an attractive way to deliver more sustainable cities. We further argue that our

theoretical experiment with complementary analytical and computer-based simulation provides

micro-economic reasoning to the main elements of the Garden City and neighbourhood unit

planning concepts.

Calfapietra, C., et al. (2015). "Urban plant physiology: adaptation-mitigation strategies

under permanent stress." Trends in Plant Science 20(2): 72-75.

Urban environments that are stressful for plant function and growth will become

increasingly widespread in future. In this opinion article, we define the concept of ‘urban plant

physiology’, which focuses on plant responses and long term adaptations to urban conditions and

on the capacity of urban vegetation to mitigate environmental hazards in urbanized settings such

as air and soil pollution. Use of appropriate control treatments would allow for studies in urban

environments to be comparable to expensive manipulative experiments. In this opinion article,

we propose to couple two approaches, based either on environmental gradients or manipulated

gradients, to develop the concept of urban plant physiology for assessing how single or multiple

environmental factors affect the key environmental services provided by urban forests.

Cahill, J. F. (2015). "Introduction to the Special Issue: Beyond traits: integrating behaviour

into plant ecology and biology." AoB Plants 7.

The way that plants are conceptualized in the context of ecological understanding is

changing. In one direction, a reductionist school is pulling plants apart into a list of measured

'traits', from which ecological function and outcomes of species interactions may be inferred.

This special issue offers an alternative, and more holistic, view: that the ecological functions

performed by a plant will be a consequence not only of their complement of traits but also of the

ways in which their component parts are used in response to environmental and social

conditions. This is the realm of behavioural ecology, a field that has greatly advanced our

understanding of animal biology, ecology and evolution. Included in this special issue are 10

articles focussing not on the tried and true metaphor that plant growth is similar to animal

movement, but instead on how application of principles from animal behaviour can improve our

ability to understand plant biology and ecology. The goals are not to draw false parallels, nor to

anthropomorphize plant biology, but instead to demonstrate how existing and robust theory

based on fundamental principles can provide novel understanding for plants. Key to this

approach is the recognition that behaviour and intelligence are not the same. Many organisms

display complex behaviours despite a lack of cognition (as it is traditionally understood) or any

hint of a nervous system. The applicability of behavioural concepts to plants is further enhanced

with the realization that all organisms face the same harsh forces of natural selection in the

context of finding resources, mates and coping with neighbours. As these ecological realities are

often highly variable in space and time, it is not surprising that all organisms-even plants-exhibit

complex behaviours to handle this variability. The articles included here address diverse topics in

behavioural ecology, as applied to plants: general conceptual understanding, plant nutrient

foraging, root-root interactions, and using and helping others. As a group, the articles in this

special issue demonstrate how plant ecological understanding can be enhanced through

incorporation of behavioural ideas and set the stage for future research in the emerging discipline

of plant behavioural ecology.

Bottalico, F., et al. (2015). Urban forest and air pollutants removal: a matter of quality of

life. 10th SISEF National Congress “Sostenere il pianeta, boschi per la vita-Ricerca e

innovazione per la tutela e la valorizzazione delle risorse forestali”, SISEF Societa'Italiana

di Selvicoltura ed Ecolo.

Cities are major actors in climate change: although they cover less than 2% of the Earth’s

surface, urban areas produce more than 60% of global carbon dioxide and significant amounts of

other greenhouse gas emissions. But cities are ecosystems: they are open and dynamic systems

which consume, transform and release materials and energy; they develop and adapt; and they

interact with humans and with other systemic components. Green Infrastructure is a relatively

new approach towards strengthening the interconnection among the different ecological

components played at landscape level. Green infrastructure does not concern just cities but is

foreseen as a powerful planning tool to bridge the gap between urban/rural areas. A green

infrastructure approach to land use and territorial planning promotes the widest range of

functions that can be performed by the same asset, thereby unlocking the greatest number of

ecosystem services. Urban and Periurban forests constitute the backbone of Green Infrastructure.

So far, ecosystem services provided by urban forests are decisive for the future of a highly

urbanized planet. Air quality is one of the most relevant factors influencing both human and

environmental health and, definitively, the quality of life. Urban forest ecosystems provide a

range of goods and services important for human well-being, commonly classified as

provisioning, regulating, cultural, and supporting services. Among them, the regulating service

of air quality improvement by air pollutants removal is a crucial one for the present and future

health of our cities. The research deals with the understanding of the urban forest component of

the green infrastructure by scaling different datasets provided by remote and on-field

investigation in order to highlight the potential performance of air pollution removal by the green

infrastructure itself. The case study of the city of Florence was investigated by scaling the spatial

distribution of urban forests mapped by remote sensing methods. A spatial model using

vegetation indices, the Leaf Area Index (LAI), re-fined by on-field LAI survey in different

structural types of urban forests, and pollution concentration data was applied to estimate PM10

and O3 removal potential. The results are discussed to predict the role of urban forests in

improving air quality in the city of Florence and to identify the opportunities and threats of using

a green infrastructure approach along strategic planning and management of urban areas and city

regions.

Andersson-Sköld, Y., et al. (2015). "An integrated method for assessing climate-related

risks and adaptation alternatives in urban areas." Climate Risk Manage 7.

The urban environment is a complex structure with interlinked social, ecological and

techni- cal structures. Global warming is expected to have a broad variety of impacts, which will

add to the complexity. Climate changes will force adaptation, to reduce climate-related risks.

Adaptation measures can address one aspect at the time, or aim for a holistic approach to avoid

maladaptation. This paper presents a systematic, integrated approach for assessing alternatives

for reducing the risks of heat waves, flooding and air pollution in urban settings, with the aim of

reducing the risk of maladaptation. The study includes strategies covering different spatial scales,

and both the current climate situation and the climate predicted under climate change scenarios.

The adaptation strategies investigated included increasing vegetation; selecting density, height

and colour of buildings; and retreat or resist (defend) against sea-level rise. Their effectiveness

was assessed with regard to not only flooding, heat stress and air quality but also with regard to

resource use, emissions to air (incl. GHG), soil and water, and people’s perceptions and

vulnerability. The effectiveness of the strategies were ranked on a common scale (from 3 to 3) in

an integrated assessment. Integrated assessments are recommended, as they help identify the

most sustainable solutions, but to reduce the risk of maladaptation they require experts from a

variety of disciplines. The most generally applicable recommendation, derived from the

integrated assessment here, taking into account both expertise from different municipal

departments, literature surveys, life cycle assessments and publics perceptions, is to increase the

urban greenery, as it contributes to several positive aspects such as heat stress mitigation, air

quality improvement, effective storm-water and flood-risk management, and it has several

positive social impacts. The most favourable alternative was compact, mid-rise, light coloured

building design with large parks/green areas and trees near buildings.

Demuzere M, C. A., Göhler M, Broadbent AM, Wouters H, van Lipzig, NPM, et al.

(2014a). The implementation of biofiltration systems, rainwater tanks and urban irrigation

in a single-layer urban canopy model. Urban Climate.

Urban vegetation is generally considered as a key tool to modify the urban energy

balance through enhanced evapotranspiration (ET). Given that vegetation is most effective when

it is healthy, stormwater harvesting and retention strategies (such as water sensitive urban

design) could be used to support vegetation and promote ET. This study presents the

implementation of a vegetated lined bio-filtration system (BFS) combined with a rainwater tank

(RWT) and urban irrigation system in the single-layer urban canopy model Community Land

Model-Urban. Runoff from roof and impervious road surface fractions is harvested and used to

support an adequate soil moisture level for vegetation in the BFS. In a first stage, modelled soil

moisture dynamics are evaluated and found reliable compared to observed soil moisture levels

from biofiltration pits in Smith Street, Melbourne (Australia). Secondly, the impact of BFS,

RWT and urban irrigation on ET is illustrated for a two-month period in 2012 using varying

characteristics for all components. Results indicate that (i) a large amount of stormwater is

potentially available for indoor and outdoor water demands, including irrigation of urban

vegetation, (ii) ET from the BFS is an order of magnitude larger compared to the contributions

from the impervious surfaces, even though the former only covers 10% of the surface fraction

and (iii) attention should be paid to the cover fraction and soil texture of the BFS, size of the

RWT and the surface fractions contributing to the collection of water in the RWT. Overall, this

study reveals that this model development can effectuate future research with state-of-the-art

urban climate models to further explore the benefits of vegetated biofiltration systems as a water

sensitive urban design tool optimised with an urban irrigation system to maintain healthy

vegetation.

Wu, J. (2014). "Urban ecology and sustainability: The state-of-the-science and future

directions." Landscape and Urban Planning 125(0): 209-221.

Ecosystems and landscapes around the world have become increasingly domesticated

through urbanization. Cities have been the engines of socioeconomic development but also the

centers of major environmental problems since the industrial revolution. Numerous studies have

shown that our urban ecosystems and landscapes are on an unsustainable trajectory. Global

sustainability depends critically on cities, and urban ecology can – and needs to – play a key role

in the transition toward sustainability. In this paper, I review different definitions and

perspectives of urban ecology, discuss major advances and key issues, and propose a framework

to help move the field forward. After almost 90 years of development, urban ecology has

evolved into a truly transdisciplinary enterprise that integrates ecological, geographical,

planning, and social sciences. The most salient thrust of current research activities in the field is

the emerging urban sustainability paradigm which focuses on urban ecosystem services and their

relations to human well-being. While urbanization is complex in many ways, we do know a lot

about its patterns, processes, and effects. More specifically, we know a great deal about urban

growth patterns in space and time, the underlying drivers and mechanisms, and myriad effects of

urbanization on biodiversity, ecological processes, and ecosystem services. Compared to their

ancient counterparts, contemporary cities tend to be bigger in physical size and ecological

footprint, faster in growth rate in terms of both population and urbanized land, and more

irregular in landscape composition and configuration. As coevolving human-environment

systems, cities are spatially heterogeneous, complex adaptive systems. As such, the dynamic

trajectory of cities can never be fully predicted or controlled, but can and should be influenced or

guided in more desirable directions through planning and design activities that are based on

urban ecological knowledge and sustainability principles.

Weber, F., et al. (2014). "A walk on the wild side: Perceptions of roadside vegetation

beyond trees." Urban Forestry & Urban Greening 13(2): 205-212.

Urban nature is of vital importance for human well-being in an increasingly urbanized

world. Despite the wide variety of urban greenspaces, previous research has mostly focussed on

parks and in particular presence of trees. Although streets are fundamental urban structures and

offer an array of green elements beyond trees, the perception and valuation of other kinds of

roadside vegetation by urban residents is understudied so far. This study explores the range of

roadside vegetation and associated ecosystem services perceived by city dwellers in densely

populated inner city districts of two German cities. Further, we explored how wild-grown

roadside vegetation is valued by interviewees. Results confirmed the important role of trees but

also demonstrated that city dwellers perceive a variety of cultivated and “wild” green

components other than trees. Respondents attached a wide range of meanings and values to

roadside greenery and showed a surprisingly high awareness of associated ecosystem services.

Wild urban roadside vegetation met with high approval, although planted and maintained

vegetation was preferred. Our study illustrated that trees and other elements of roadside

vegetation fulfil important functions in the view of the public. For many respondents, ecological

and economical functions of roadside vegetation were more important than orderliness. This

indicates opportunities for enhancing the biodiversity of urban streetscapes. As public green

spaces are in short supply in many cities, enhancing cultivated and wild roadside vegetation

could help to deliver ecosystem services in the areas near where people move and live.

Weber, F., et al. (2014). "Herbaceous plants as filters: Immobilization of particulates along

urban street corridors." Environmental Pollution 186: 234-240.

Among air pollutants, particulate matter (PM) is considered to be the most serious threat

to human health. Plants provide ecosystem services in urban areas, including reducing levels of

PM by providing a surface for deposition and immobilization. While previous studies have

mostly addressed woody species, we focus on herbaceous roadside vegetation and assess the role

of species traits such as leaf surface roughness or hairiness for the immobilization of PM. We

found that PM deposition patterns on plant surfaces reflect site-specific traffic densities and that

strong differences in particulate deposition are present among species. The amount of

immobilized PM differed according to particle type and size and was related to specific plant

species traits. Our study suggests that herbaceous vegetation immobilizes a significant amount of

the air pollutants relevant to human health and that increasing biodiversity of roadside vegetation

supports air filtration and thus healthier conditions along street corridors.

Vico, G., et al. (2014). "Ecohydrology of street trees: design and irrigation requirements for

sustainable water use." Ecohydrology 7.

Whereas the beneficial effects of urban vegetation have long been recognized, growing

conditions in urban environments, especially for street trees, are typically harsh and limited by

low water availability. Supplemental irrigation may be used to preserve aesthetic quality and

ability to provide ecosystem services of urban vegetation but requires careful management of

available economic and water resources to reduce urban water footprint. To this purpose,

decision makers need quantitative tools, requiring few, physically based parameters and

accounting for the uncertainties and future scenarios of the hydroclimatic forcing. Focusing on

in-row and isolated trees, a minimalist description of street tree water balance is proposed here,

including rainfed and irrigated conditions, and explicitly accounting for tree water requirements,

growing conditions (in terms of soil properties and extension of bare soil, permeable and

impervious pavements surrounding the tree) and rainfall unpredictability. The proposed model

allows the quantification of tree cooling capacity, water stress occurrence and irrigation

requirements, as a function of soil, plant and climate characteristics, thus providing indications

regarding the tree ability to provide ecosystem services and management costs. In particular, an

analysis of different planting designs suggests that a balanced design consisting in bare soil and

permeable pavement with size equal to the lateral canopy extension is optimal for water

conservation, tree cooling capacity and health. The proposed model provides useful indications

towards the definition of site-specific guidelines for species selection and planting design, for

sustainable urban vegetation.

Van Renterghem, T. (2014). "Guidelines for optimizing road traffic noise shielding by non-

deep tree belts." Ecological Engineering 69: 276-286.

This paper discusses that a non-deep tree belt along a road can be an interesting solution

to achieve road traffic noise reduction. Noise shielding is mainly obtained as a combination of

multiple scattering in the tree trunk layer and due to the presence of an acoustically soft soil. A

large dataset of full-wave and highly detailed numerical simulations, based as much as possible

on measured input data, shows that high biomass density should be strived for as a general rule.

This conflicts, however, with practical limitations regarding access to light, nutrients and water

for the trees. Some interesting approaches have been identified to relax the need for high biomass

density, without affecting noise shielding to an important extent. Rectangular planting schemes,

where the spacing orthogonal to the road can be increased, omitting full rows parallel to the road

length axis, and thinning inside the belt are examples of such measures. It is discussed that the

specific choice of a planting scheme could make a tree belt along a road an efficient noise

reducing measure or not.

Van den Berg, A. E., et al. (2014). "Evaluating restoration in urban green spaces: Does

setting type make a difference?" Landscape and Urban Planning 127: 173-181.

A growing body of research suggests that natural settings are more effective in providing

restoration from depleted emotional and cognitive resources than built settings. However, there is

a lack of evidence-based guidelines on which options for urban green space design and

management are most effective in providing restoration. To address this need, the present study

examined the restorative impacts of urban public spaces differing in naturalness. After having

been pre-stressed by watching a scary movie, 102 participants were randomly assigned to

viewing one of four photo/video presentations depicting an urban street, parkland, tended

woodland, or wild woods. Self-reported mood and restorative state were measured at baseline,

after the stressor and after viewing the environment. After controlling for stress reactivity,

participants in the natural conditions showed stronger recovery on all dependent measures than

those in the urban street condition. Differences in recovery among the natural settings did not

reach significance. Keyword analysis revealed that the wild woods were described as more

arousing than the parkland and tended woodland. There was substantial variation in recovery of

vitality within natural conditions, which was related to perceptions of naturalness. In general, the

findings suggest that restoration in urban public spaces depends on individual perceptions and

needs as well as physical characteristics of the setting.

Torpy, F. R., et al. (2014). "Profiling indoor plants for the amelioration of high CO2

concentrations." Urban Forestry & Urban Greening 13(2): 227-233.

Research over the last three decades has shown that indoor plants can reduce most types

of urban air pollutants, however there has been limited investigation of their capacity to mitigate

elevated levels of CO2. This study profiled the CO2 removal potential of eight common indoor

plant species, acclimatised to both indoor and glasshouse lighting levels, to develop baseline data

to facilitate the development of indoor plant installations to improve indoor air quality by

reducing excess CO2 concentrations. The results indicate that, with the appropriate choice of

indoor plant species and a targeted increase in plant specific lighting, plantscape installations

could be developed to remove a proportion of indoor CO2. Further horticultural research and

development will be required to develop optimum systems for such installations, which could

potentially reduce the load on ventilation systems.

Takayama, N., et al. (2014). "Emotional, Restorative and Vitalizing Effects of Forest and

Urban Environments at Four Sites in Japan." International Journal of Environmental

Research and Public Health 11(7): 7207-7230.

The present study investigated the well-being effects of short-term forest walking and

viewing ("forest bathing"). The hypothesis in our study was that both environment (forest vs.

urban) and activity (walking and viewing) would influence psychological outcomes. An

additional aim was to enhance basic research using several psychological methods. We

conducted the experiments using 45 respondents in four areas of Japan from August to

September, 2011. The hypothesis in our study was supported, because significant interaction

terms between the environment and activity were confirmed regarding the Profile of Mood States

(POMS) indexes, Restorative Outcome Scale (ROS) and Subjective Vitality Scale (SVS). No

statistical differences between the two experimental groups in any of the ten scales were found

before the experiment. However, feelings of vigor and positive effects, as well as feelings of

subjective recovery and vitality were stronger in the forest environment than in the urban

environment.

Sriprapat, W., et al. (2014). "Uptake of toluene and ethylbenzene by plants: removal of

volatile indoor air contaminants." Ecotoxicol Environ Saf 102: 147-151.

Air borne uptake of toluene and ethylbenzene by twelve plant species was examined. Of

the twelve plant species examined, the highest toluene removal was found in Sansevieria

trifasciata, while the ethylbenzene removal from air was with Chlorophytum comosum. Toluene

and ethylbenzene can penetrate the plants cuticle. However, the removal rates do not appear to

be correlated with numbers of stomata per plant. It was found that wax of S. trifasciata and

Sansevieria hyacinthoides had greater absorption of toluene and ethylbenzene, and it contained

high hexadecanoic acid. Hexadecanoic acid might be involved in toluene and ethylbenzene

adsorption by cuticles wax of plants. Chlorophyll fluorescence analysis or the potential quantum

yield of PSII (Fv/Fm) in toluene exposed plants showed no significant differences between the

control and the treated plants, whereas plants exposed to ethylbenzene showed significant

differences or those parameters, specifically in Dracaena deremensis (Lemon lime), Dracaena

sanderiana, Kalanchoe blossfeldiana, and Cordyline fruticosa. The Fv/Fm ratio can give insight

into the ability of plants to tolerate (indoor) air pollution by volatile organic chemicals (VOC).

This index can be used for identification of suitable plants for treating/sequestering VOCs in

contaminated air.

Skoulika, F., et al. (2014). "On the thermal characteristics and the mitigation potential of a

medium size urban park in Athens, Greece." Landscape and Urban Planning 123: 73-86.

The urban heat island (UHI) is one of the most studied phenomena of urban climate. It

deals with the increased ambient temperatures in the cities’ central areas compared to their

suburban or rural surroundings (Santamouris, 2001). Significant research has been carried out by

various researchers all over the world in order to understand the phenomenon’s characteristics

and document its magnitude (Arnfield, 2003; Ghiaus, Allard, Santamouris, Georgakis, & Nicol,

2006; Oke, 1982).

Measurements have been performed during summer in and around a medium size urban

park located in the western part of Athens, Greece. Additional temperature data from 15 urban

and suburban stations are used to perform comparative analysis at the city level. The park

presents an important temperature inhomogeneity during both day and night. Average nocturnal

cool island intensities against the reference urban stations varied between −0.7 K and −2.8 K,

while during the daytime the average maximum cool island intensity (CII) was between −0.2 K

and −2.6 K. A statistical significant correlation between the CII and the population density is

found for both day and night. The park was warmer than the urban stations for ambient

temperatures lower than 34◦C, while for higher urban temperatures the park was cooler and the

absolute CII increased as a function of the ambient temperature. An important correlation with

the wind speed is observed for wind speeds higher than 6 m/s. The mitigation potential of the

park was assessed by performing three types of traverses around the park. The park cooling

intensity was varying between 3.3 and 3.8 K, while the temperature gradient along the traverses

changes as a function of the thermal properties of the urban areas and was between 0.2 and 1.4

K/100 m. The park cooling intensity presents a strong correlation with the wind speed for values

higher than 5 m/s. The climatic influence of the park was extended up to 300 m from the borders

of the park.

Pearce, M., et al. (2014). "Who children spend time with after school: associations with

objectively recorded indoor and outdoor physical activity." International Journal of

Behavioral Nutrition and Physical Activity 11(1): 45.

Background: Understanding how the determinants of behaviour vary by context may

support the design of interventions aiming to increase physical activity. Such factors include

independent mobility, time outdoors and the availability of other children. At present little is

known about who children spend their time with after school, how this relates to time spent

indoors or outdoors and activity in these locations. This study aimed to quantify who children

spend their time with when indoors or outdoors and associations with moderate to vigorous

physical activity (MVPA).

Methods: Participants were 427 children aged 10–11 from Bristol, UK. Physical activity

was recorded using an accelerometer (Actigraph GT1M) and matched to Global Positioning

System receiver (Garmin Foretrex 201) data to differentiate indoor and outdoor location.

Children self-reported who they spent time with after school until bed-time using a diary. Each

10 second epoch was coded as indoors or outdoors and for ‘who with’ (alone, friend,

brother/sister, mum/dad, other grown-up) creating 10 possible physical activity contexts. Time

spent and MVPA were summarised for each context. Associations between time spent in the

different contexts and MVPA were examined using multiple linear regression adjusting for

daylight, age, deprivation and standardised body mass index.

Results: During the after school period, children were most often with their mum/dad or

alone, especially when indoors. When outdoors more time was spent with friends (girls: 32.1%;

boys: 28.6%) than other people or alone. Regression analyses suggested hours outdoors with

friends were positively associated with minutes of MVPA for girls (beta-coefficient [95% CI]:

17.4 [4.47, 30.24]) and boys (17.53 [2.76, 32.31]). Being outdoors with brother/sister was

associated with MVPA for girls (21.2 [14.17, 28.25]) but not boys. Weaker associations were

observed for time indoors with friends (girls: 4.61 [1.37, 7.85]; boys: (7.42 [2.99, 11.85]) and

other adults (girls: 5.33 [2.95, 7.71]; boys: (4.44 [1.98, 6.90]). Time spent alone was not

associated with MVPA regardless of gender or indoor/outdoor location.

Conclusions: Time spent outdoors with other children is an important source of MVPA

after school. Interventions to increase physical activity may benefit from fostering friendship

groups and limiting the time children spend alone.

Pandit, R., et al. (2014). "Valuing public and private urban tree canopy cover." Australian

Journal of Agricultural and Resource Economics 58(3): 453-470.

In this paper, we estimate the effect of tree canopy cover on sales price of urban

residential properties in Perth, Western Australia. Using a data set of 5606 single family homes

sold in 2009 and a spatial hedonic model with three spatial effects – spatial-temporal lag on

dependent variable, spatial error, and spatially lagged independent variables – we estimated the

location-specific effect of tree canopy cover. Tree canopy cover increases the property value

when located on adjacent public space, but decreases the value when it is on own property and

on the adjacent property within 20 m of property boundary. The results are suggestive that

council urban tree planting programs provide significant private benefits to homeowners.

Neema, M. N. and J. Jahan (2014). "An innovative approach to mitigate vehicular emission

through roadside greeneries: A case study on arterial roads of Dhaka city." Journal of

Data Analysis and Information Processing 2014.

With the surge of human population, the need for transportation of goods and people also

concomitantly increases, resulting in urban air pollution through emission from motorized traffic

especially in developing countries. The extent of environmental pollution in an urban setting is

significantly influenced by the pollutants of vehicular fuel combustion. Many effective measures

are required in cities to sequester carbon thereby helping to reduce automobile pollution.

Roadside greeneries can serve as ecological elements which reduce the concentration of

pollutants from vehicular emissions by their direct involvement in absorbing vehicular emitted

carbon. In this context, in this study an attempt has been taken to assess contribution of roadside

greeneries in absorbing vehicular carbon dioxide emission. A case study has been conducted on

arterial roads of mega city Dhaka to quantify the vehicular carbon emission and correlate it with

roadside trees to absorb the emitted carbon dioxide. It is noted that in Dhaka city, carbon dioxide

is accounted for more than ninety percent of air pollution. To achieve our goals, two busiest

arterial roads (namely Mirpur Road and Rokeya Shoroni Road) were taken into account to

quantify vehicular carbon emission as well as assess carbon absorption by roadside greeneries.

Carbon ab- sorption by different sizes of trees has been quantified using the amount of woody

biomass. In addition, absorption by grass-shrubs-herbs has been quantified by the area they

cover. The results thus obtained show that in- deed the road with more side greeneries absorbs

more vehicular emitted carbon dioxide. It is therefore evident that plantation of more roadside

trees is an effective measure of reducing air pollution and consequently turning a city to become

healthier and more suitable for living.

Mavrogianni, A., et al. (2014). "The impact of occupancy patterns, occupant-controlled

ventilation and shading on indoor overheating risk in domestic environments." Build

Environ 78.

It is widely recognised that a major source of uncertainty in building performance

simulation relates to occupancy and behavioural assumptions. This paper aims to assess the

relative impact of lifestyle patterns, occupant-controlled window opening and shading use on

indoor overheating risk levels in dwellings. The indoor thermal environment of a set of broadly

representative archetypes of the London housing stock was simulated using dynamic thermal

modelling. Two lifestyle patterns and four scenarios of window opening and shading use

schedules were combined with multiple other varying parameters (building geometry and

orientation, insulation levels, level of overshadowing by adjacent buildings), leading to a total of

27,648 modelled dwelling variants. It was found that the rankings obtained for dwellings

occupied by a family with children at school and dwellings occupied by pensioners were broadly

similar for all combinations of behaviour and the majority of overheating metrics. Lower ranking

correlations were, however, observed between simple temperature-dependent window opening

scenarios and a more sophisticated scenario of combined shading and night ventilation. This is

an indication that shading and/or night cooling could modify indoor overheating risk

significantly. The findings of the study add to a growing body of literature suggesting that the

way inhabitants occupy and operate a building has a measurable impact on thermal discomfort

and potentially the health risks associated with their exposure to high indoor temperatures. This

should be taken into consideration in the design of retrofit interventions and public health

strategies aiming to minimise such risks.

Madre, F., et al. (2014). "Green roofs as habitats for wild plant species in urban

landscapes: First insights from a large-scale sampling." Landscape and Urban Planning

122: 100-107.

The urban landscape is known to form a hostile matrix for wild plant communities

because of its sealed infrastructure surfaces. However, green roofs can reduce this hostility by

providing new spaces for wildlife directly on buildings. In this extensive study of 115 green

roofs in northern France, we focused on wild plant communities and the variables that shaped

their diversity and their taxonomic and functional compositions. A total of 176 colonizing

vascular plant species were identified; 86% were natives, demonstrating that green roofs can

serve as habitats for wild biodiversity despite their isolation in an urban landscape in three

dimensions. Nonetheless, all types of green roofs were not equal, with the substrate depth

playing a major role in the wild plant diversity. The taxonomic and functional compositions of

the colonizing plant communities were also shaped by the substrate depth, green roof age,

surface area, and height and maintenance intensity at the building scale. We did not detect any

effect of the surrounding potential habitats at the landscape scale. The study of functional traits

revealed that the wild plant communities are adapted to open xero-thermophilous conditions.

This study led us to consider an ecological typology for green roofs referred to as stratum

classification, which is based on the vegetal structures living and colonizing these anthropo-

ecosystems. Wild roofs adapted to receive spontaneous species could play an interesting role in

urban biodiversity dynamics if they continue to be developed at large scales in cities.

Li, Y. and R. W. Babcock (2014). "Green roofs against pollution and climate change. A

review." Agronomy for Sustainable Development 34(4): 695-705.

Green roofs recover green spaces in urban areas and benefit the public, farmers, and

wildlife by providing many environmental, ecological, and economic advantages. Green roofs

reduce stormwater runoff, mitigate urban heat island effects, absorb dust and smog, sequester

carbon dioxide, produce oxygen, create space for food production, and provide natural habitat for

animals and plants. Here, we studied the environmental impact of green roofs in terms of runoff

quality and greenhouse gas CO2 sequestration. We screened more than 650 scientific papers and

we reviewed detailed findings from 52 publications. There are two major points: (1) Concerning

pollution, the concentrations of minor pollutants, such as heavy metals, biochemical oxygen

demand (BOD), total suspended solids (TSS), and turbidity, are small and thus do not pose an

immediate threat to the environment. However, the concentrations of major pollutants, such as

nitrogen of 0.49–9.01 mg/l and phosphorus of 0.04–25 mg/l, vary highly for different green roofs

and can adversely affect runoff quality. Nutrient leaching may be controllable through proper

mitigation measures including better design and system management which require further

research. According to both laboratory experiments and field monitoring data, the main factors

affecting runoff quality are precipitation properties, growth media composition and depth, plant

species, and maintenance protocols. Research gaps exist in quantifying how these factors affect

leachate pollutant load. Systematic studies are needed for improving green roof designs to reduce

adverse impacts. (2) Concerning CO2 sequestration, studies reveal that green roofs directly

sequester substantial amounts of carbon in plants and soils through photosynthesis. Green roofs

reduce ambient CO2 concentrations in the vicinities. Green roofs also indirectly reduce CO2

releases from power plants and furnaces by reducing demand for heating and cooling, suggesting

long-term economic and environmental benefits of green roofs.

Lennon, M., et al. (2014). "Urban Design and Adapting to Flood Risk: The Role of Green

Infrastructure." Journal of Urban Design 19(5): 745-758.

This Practice Paper identifies and critically examines three alternative approaches and

associated design philosophies in response to the problem of urban flooding. It traces the reasons

why these three approaches have emerged and discusses the attributes of each. Following this, it

examines the potential of the green infrastructure approach as a means to realize evolutionary

resilience? in designing urban environments for enhanced drainage management. The paper then

contrasts the three alternative approaches to flood risk management and identifies some

implications of advancing the green infrastructure concept in urban design activities.

Jin, S. J., et al. (2014). "Evaluation of impacts of trees on PM2.5 dispersion in urban

streets." Atmos Environ 99.

Reducing airborne particulate matter (PM), especially PM2.5 (PM with aerodynamic

diameters of 2.5 mm or less), in urban street canyons is critical to the health of central city

population. Tree-planting in urban street canyons is a double-edged sword, providing landscape

benefits while inevitably resulting in PM2.5 concentrating at street level, thus showing negative

environmental effects. Thereby, it is necessary to quantify the impact of trees on PM2.5

dispersion and obtain the optimum structure of street trees for minimizing the PM2.5

concentration in street canyons. However, most of the previous findings in this field were

derived from wind tunnel or numerical simulation rather than on-site measuring data. In this

study, a seasonal investigation was performed in six typical street canyons in the residential area

of central Shanghai, which has been suffering from haze pollution while having large numbers of

green streets. We monitored and measured PM2.5 concentrations at five heights, structural

parameters of street trees and weather. For tree-free street canyons, declining PM2.5

concentrations were found with increasing height. However, in presence of trees the reduction

rate of PM2.5 concentrations was less pronounced, and for some cases, the concentrations even

increased at the top of street canyons, indi- cating tree canopies are trapping PM2.5. To quantify

the decrease of PM2.5 reduction rate, we developed the attenuation coefficient of PM2.5

(PMAC). The wind speed was significantly lower in street canyons with trees than in tree-free

ones. A mixed-effects model indicated that canopy density (CD), leaf area index (LAI), rate of

change of wind speed were the most significant predictors influencing PMAC. Further regression

analysis showed that in order to balance both environmental and landscape benefits of green

streets, the optimum range of CD and LAI was 50%e60% and 1.5e2.0 respectively. We

concluded by suggesting an optimized tree-planting pattern and discussing strategies for a better

green streets planning and pruning.

Hykš, O. and K. Neubergová (2014). "Mature Vegetation along Roads." Transactions on

Transport Sciences: 117.

The article deals with the issue of vegetation, particularly mature vegetation, along

transport routes. Since rather heated discussions on this topic have recently appeared, particularly

in relation to road safety, the authors of this article decided to present this issue in wider context

and from various viewpoints. The starting point for this issue is mentioned in the introduction.

The next part deals with the history of planting tree alleys in the Czech Republic. Subsequently,

a brief summary of advantages and drawbacks of mature vegetation along transport routes is

presented. The next part of the article discusses the environmental bases and, last but not least,

the article deals with the impact of mature vegetation on road safety.

Hilde, T. and R. Paterson (2014). "Integrating ecosystem services analysis into scenario

planning practice: Accounting for street tree benefits with i-Tree valuation in Central

Texas." Journal of Environmental Management 146: 524-534.

Scenario planning continues to gain momentum in the United States as an effective

process for building consensus on long-range community plans and creating regional visions for

the future. However, efforts to integrate more sophisticated information into the analytical

framework to help identify important ecosystem services have lagged in practice. This is

problematic because understanding the tradeoffs of land consumption patterns on ecological

integrity is central to mitigating the environmental degradation caused by land use change and

new development. In this paper we describe how an ecosystem services valuation model, i-Tree,

was integrated into a mainstream scenario planning software tool, Envision Tomorrow, to assess

the benefits of public street trees for alternative future development scenarios. The tool is then

applied to development scenarios from the City of Hutto, TX, a Central Texas Sustainable Places

Project demonstration community. The integrated tool represents a methodological improvement

for scenario planning practice, offers a way to incorporate ecosystem services analysis into

mainstream planning processes, and serves as an example of how open source software tools can

expand the range of issues available for community and regional planning consideration, even in

cases where community resources are limited. The tool also offers room for future

improvements; feasible options include canopy analysis of various future land use typologies, as

well as a generalized street tree model for broader U.S. application.

Haase, D., et al. (2014). "A Quantitative Review of Urban Ecosystem Service Assessments:

Concepts, Models, and Implementation." AMBIO 43(4): 413-433.

Although a number of comprehensive reviews have examined global ecosystem services

(ES), few have focused on studies that assess urban ecosystem services (UES). Given that more

than half of the world’s population lives in cities, understanding the dualism of the provision of

and need for UES is of critical importance. Which UES are the focus of research, and what types

of urban land use are examined? Are models or decision support systems used to assess the

provision of UES? Are trade-offs considered? Do studies of UES engage stakeholders? To

address these questions, we analyzed 217 papers derived from an ISI Web of Knowledge search

using a set of standardized criteria. The results indicate that most UES studies have been

undertaken in Europe, North America, and China, at city scale. Assessment methods involve bio-

physical models, Geographical Information Systems, and valuation, but few study findings have

been implemented as land use policy.

Feyisa, G. L., et al. (2014). "Efficiency of parks in mitigating urban heat island effect: An

example from Addis Ababa." Landscape and Urban Planning 123: 87-95.

Urban green infrastructure can to a certain extent mitigate urban warming. However, the

cooling effect of plants varies with space, time and plant-specific properties. To contribute to our

understanding of the cooling effect of vegetation on urban surface and air temperature, 21 parks

in Addis Ababa were studied. Air temperature and humidity were measured for 60 plots in nine

of the parks for 15 days. Furthermore, the thermal band of Landsat ETM+ was used to examine

the cooling impact of all 21 parks on a larger spatial scale. Linear mixed-effects models were

used to examine the relationship between characteristics of the vegetation and observed

temperature. It emerged that Eucalyptus sp. had a significantly higher cooling effect than any

other species group (P < 0.05) and the species with the least effect on temperature were Grevillea

and Cupressus. On a larger spatial scale, the cooling effect of parks on their surroundings (Park

Cooling Intensity, PCI) was positively related to the NDVI and area of parks (P < 0.01). A

negative relationship was observed between PCI and park shape index (SI). The range within

which the cooling effect could be observed (Park Cooling Distance, PCD) was positively related

to SI and park area. The maximum PCI was 6.72 °C and the maximum PCD was estimated at

240 m. We conclude that the cooling effect is mainly determined by species group, canopy

cover, size and shape of parks. Thus, the study provides insights regarding the importance of

species choice and spatial design of green spaces in cooling the environment.

Ferrini, F., et al. (2014). "Trees in the urban environment: Response mechanisms and

benefits for the ecosystem should guide plant selection for future plantings." Agrochimica

58.

It is well known that, at present, more than a half of the world population live in the

built-up areas (in Europe almost 80%) and the urbanization trend will continue as the population

increases and more people will live in large cities. In this scenario arboriculture and urban

forestry should have a main role in the effort to manage urbanization and to create livable cities

and it is certain that all green areas, starting from the single tree specimens to periurban forests

which, in some way, recall the "concept of nature", can fulfil a paramount function in improving

life quality and in reaching the minimal threshold for human well-being. What is going to happen

next - over 10-15 years - will obviously be of the greatest interest to all people concerned with

urban environment. This latter poses some constraints to tree growth and survival: drought, poor

soil quality and compaction, pollutants, salinity, pathogens, light heterogeneity, and conflicts

with human activities often cause premature plant death or limit plant growth, thus reducing the

net benefit by urban green areas. It is therefore important to better understand the dynamics

leading to tree decline in the urban environment, and to develop strategies and techniques aimed

at improving the horticultural tolerance (i.e. the capacity to provide benefits, not only to survive,

under stressful conditions) of urban trees. These include nursery pre-conditioning techniques and

post-planting management techniques, but a key role is played by species selection. Hundreds of

species are used in the urban environment, but selection criteria are frequently based upon

aesthetics and whether the species are native or not, rather than on the tolerance to typical

stresses imposed by the built environment and on the capacity to provide substantial benefits

therein.

Edmondson, J. L., et al. (2014). "Urban tree effects on soil organic carbon." PLoS ONE

9(7): e101872.

Urban trees sequester carbon into biomass and provide many ecosystem service benefits

aboveground leading to worldwide tree planting schemes. Since soils hold ,75% of ecosystem

organic carbon, understanding the effect of urban trees on soil organic carbon (SOC) and soil

properties that underpin belowground ecosystem services is vital. We use an observational study

to investigate effects of three important tree genera and mixed-species woodlands on soil

properties (to 1 m depth) compared to adjacent urban grasslands. Aboveground biomass and

belowground ecosystem service provision by urban trees are found not to be directly coupled.

Indeed, SOC enhancement relative to urban grasslands is genus-specific being highest under

Fraxinus excelsior and Acer spp., but similar to grasslands under Quercus robur and mixed

woodland. Tree cover type does not influence soil bulk density or C:N ratio, properties which

indicate the ability of soils to provide regulating ecosystem services such as nutrient cycling and

flood mitigation. The trends observed in this study suggest that genus selection is important to

maximise long-term SOC storage under urban trees, but emerging threats from genus-specific

pathogens must also be considered.

Dobbs, C., et al. (2014). "Multiple ecosystem services and disservices of the urban forest

establishing their connections with landscape structure and sociodemographics."

Ecological Indicators 43: 44-55.

The promotion of sustainable cities is critical under future environmental change and

population growth. Cities in the present and future can ensure the provision of ecosystem

services to their urban inhabitants. The urban forest is one of the main suppliers of ecosystem

services in urban areas, and can provide the base information to quantify ecosystem services and

disservices, detecting the areas were low provision of those occur. In this study multiple

ecosystem services and disservices were quantified using transferable indicators in order to

detect areas for environmental improvement. The set of spatially explicit indicators enables the

detection of areas of low and high provision of ecosystem services. The analysis showed

synergies existing among regulating, provisioning and supporting services, while trade-offs were

found with cultural services and regulating, provisioning and supporting services. Ecosystem

services provision was positively related to the amount of vegetation and negatively related to its

degree of fragmentation. A high provision of ecosystem services was found in less populated

areas, with more educated and affluent people, highlighting the strong relations existing between

social vulnerabilities and areas of low provision of services. Results from this research provide

insights on the role of policy makers on better distributed supply of ecosystem services and on

how the landscape structure can be modified to plan for sustainable cities.

Demuzere, M., et al. (2014). "Mitigating and adapting to climate change: Multi-functional

and multi-scale assessment of green urban infrastructure." Journal of Environmental

Management 146: 107-115.

In order to develop climate resilient urban areas and reduce emissions, several

opportunities exist starting from conscious planning and design of green (and blue) spaces in

these landscapes. Green urban infrastructure has been regarded as beneficial, e.g. by balancing

water flows, providing thermal comfort. This article explores the existing evidence on the

contribution of green spaces to climate change mitigation and adaptation services. We suggest a

framework of ecosystem services for systematizing the evidence on the provision of bio-physical

benefits (e.g. CO2 sequestration) as well as social and psychological benefits (e.g. improved

health) that enable coping with (adaptation) or reducing the adverse effects (mitigation) of

climate change. The multi-functional and multi-scale nature of green urban infrastructure

complicates the categorization of services and benefits, since in reality the interactions between

various benefits are manifold and appear on different scales. We will show the relevance of the

benefits from green urban infrastructures on three spatial scales (i.e. city, neighborhood and site

specific scales). We will further report on co-benefits and trade-offs between the various services

indicating that a benefit could in turn be detrimental in relation to other functions. The

manuscript identifies avenues for further research on the role of green urban infrastructure, in

different types of cities, climates and social contexts. Our systematic understanding of the bio-

physical and social processes defining various services allows targeting stressors that may

hamper the provision of green urban infrastructure services in individual behavior as well as in

wider planning and environmental management in urban areas.

Dela Cruz, M., et al. (2014). "Can ornamental potted plants remove volatile organic

compounds from indoor air? A review." Environ Sci Pollut Res Int 21(24): 13909-13928.

Volatile organic compounds (VOCs) are found in indoor air, and many of these can affect

human health (e.g. formaldehyde and benzene are carcinogenic). Plants affect the levels of VOCs

in indoor environments, thus they represent a potential green solution for improving indoor air

quality that at the same time can improve human health. This article reviews scientific studies of

plants' ability to remove VOCs from indoor air. The focus of the review is on pathways of VOC

removal by the plants and factors affecting the efficiency and rate of VOC removal by plants.

Laboratory based studies indicate that plant induced removal of VOCs is a combination of direct

(e.g. absorption) and indirect (e.g. biotransformation by microorganisms) mechanisms. They also

demonstrate that plants' rate of reducing the level of VOCs is influenced by a number of factors

such as plant species, light intensity and VOC concentration. For instance, an increase in light

intensity has in some studies been shown to lead to an increase in removal of a pollutant. Studies

conducted in real-life settings such as offices and homes are few and show mixed results.

Curtis, A. J., et al. (2014). "Biogenic volatile organic compound emissions from nine tree

species used in an urban tree-planting program." Atmos Environ 95.

The biogenic volatile organic compound (BVOC) emissions of nine urban tree species

were studied to assess the air quality impacts from planting a large quantity of these trees in the

City and County of Denver, Colorado, through the Mile High Million tree-planting initiative.

The deciduous tree species studied were Sugar maple, Ohio buckeye, northern hackberry,

Turkish hazelnut, London planetree, American basswood, Littleleaf linden, Valley Forge elm,

and Japanese zelkova. These tree species were selected using the i-Tree Species Selector

(itreetools.org). BVOC emissions from the selected tree species were investigated to evaluate the

Species Selector data under the Colorado climate and environmental growing conditions.

Individual tree species were subjected to branch enclosure experiments in which foliar emissions

of BVOC were collected onto solid adsorbent cartridges. The cartridge samples were analyzed

for monoterpenes (MT), sesquiterpenes (SQT), and other C10–C15 BVOC using thermal

desorption-gas chromatography–flame ionization detection/mass spectroscopy (GC–FID/MS).

Individual compounds and their emission rates (ER) were identified. MT were observed in all

tree species, exhibiting the following total MT basal emission rates (BER; with a 1−σ lower

bound, upper bound uncertainty window): Sugar maple, 0.07 (0.02, 0.11) μg g−1 h−1; London

planetree, 0.15 (0.02, 0.27) μg g−1 h−1; northern hackberry, 0.33 (0.09, 0.57) μg g−1 h−1;

Japanese zelkova, 0.42 (0.26, 0.58) μg g−1 h−1; Littleleaf linden, 0.71 (0.33, 1.09) μg g−1 h−1;

Valley Forge elm, 0.96 (0.01, 1.92) μg g−1 h−1; Turkish hazelnut, 1.30 (0.32, 2.23) μg g−1 h−1;

American basswood, 1.50 (0.40, 2.70) μg g−1 h−1; and Ohio buckeye, 6.61 (1.76, 11.47) μg g−1

h−1. SQT emissions were seen in five tree species with total SQT BER of: London planetree,

0.11 (0.01, 0.20) μg g−1 h−1; Japanese zelkova, 0.11 (0.05, 0.16) μg g−1 h−1; Littleleaf linden,

0.13 (0.06, 0.21) μg g−1 h−1; northern hackberry, 0.20 (0.11, 0.30) μg g−1 h−1; and Ohio

buckeye, 0.44 (0.06, 0.83) μg g−1 h−1. The following trees exhibited emissions of other C10–

C15 volatile organic compounds (VOC): Littleleaf linden, 0.15 (0.10, 0.20) μg g−1 h−1; Ohio

buckeye, 0.39 (0.14, 0.65) μg g−1 h−1; and Turkish hazelnut, 0.72 (0.49, 0.95) μg g−1 h−1. All

tree species studied in this experiment were confirmed to be low isoprene emitters. Compared to

many other potential urban tree species, the selected trees can be considered low to moderate

BVOC emitters under Colorado growing conditions, with total emission rates one-tenth to one-

hundredth the rates of potential high-BVOC emitting trees. The emissions data were used to

estimate the impact of this targeted tree planting on the urban BVOC flux and atmospheric VOC

burden. Selecting the low-emitting tree species over known high BVOC emitters is equivalent to

avoiding VOC emissions from nearly 500,000 cars from the inner city traffic.

Cuinica, L. G., et al. (2014). "Effect of air pollutant NO2 on Betula pendula, Ostrya

carpinifolia and Carpinus betulus pollen fertility and human allergenicity." Environ Pollut

186.

Pollen of Betula pendula, Ostrya carpinifolia and Carpinus betulus was exposed in vitro

to two levels of NO2 (about 0.034 and 0.067 ppm) – both below current atmospheric hour-limit

value acceptable for human health protection in Europe (0.11 ppm for NO2). Experiments were

performed under artificial solar light with temperature and relative humidity continuously

monitored. The viability, germination and total soluble proteins of all the pollen samples exposed

to NO2 decreased significantly when compared with the non-exposed. The polypeptide profiles

of all the pollen samples showed bands between 15 and 70 kDa and the exposure to NO2 did not

produce any detectable changes in these profiles. However, the immunodetection assays

indicated higher IgE recognition by patient sera sensitized to the pollen extracts from all exposed

samples in comparison to the non-exposed samples. The common reactive bands to the three

pollen samples correspond to 58 and 17 kDa proteins.

Copeland, C. (2014). "Green Infrastructure and issues in managing urban stormwater."

Congressional Research Service, Washington, DC.

For decades, stormwater, or runoff, was considered largely a problem of excess rainwater

or snowmelt impacting communities. Prevailing engineering practices were to move stormwater

away from cities as rapidly as possible to avoid potential damages from flooding. More recently,

these practices have evolved and come to recognize stormwater as a resource that, managed

properly within communities, has multiple benefits.

Stormwater problems occur because rainwater that once soaked into the ground now runs

off hard surfaces like rooftops, parking lots, and streets in excessive amounts. This runoff flows

into storm drains and ultimately into lakes and streams, carrying pollutants that are harmful to

aquatic life and public health. Traditional approaches to managing urban stormwater have

utilized so-called “gray infrastructure,” including pipes, gutters, ditches, and storm sewers. More

recently, interest has grown in “green infrastructure” technologies and practices in place of or in

combination with gray infrastructure. Green infrastructure systems use or mimic natural

processes to infiltrate, evapotranspire, or reuse stormwater runoff on the site where it is

generated. These practices keep rainwater out of the sewer system, thus preventing sewer

overflows and also reducing the amount of untreated runoff discharged to surface waters.

Cities’ adoption of green technologies and practices has increased, motivated by several

factors. One motivation is environmental and resource benefits. Advocates, including

environmental groups, landscape architects, and urban planners, have drawn attention to these

practices. But an equally important motivation, perhaps larger than environmental benefits, is

cost-saving opportunities for cities that face enormous costs of stormwater infrastructure projects

to meet requirements of the Clean Water Act. Other potential benefits include reduced flood

damages, improved air quality, and improved urban aesthetics. At the same time, barriers to

implementing green infrastructure include lack of information on performance and cost-

effectiveness and uncertainty whether the practices will contribute to achieving water quality

improvements.

Another key barrier is lack of funding. At the federal level, there is no single source of

dedicated federal funding to design and implement green infrastructure solutions. Without

assistance, communities take several approaches to financing wastewater and stormwater

projects; the most frequently used tool is issuance of municipal bonds. As a dedicated funding

source for projects, the number of local stormwater utilities that charge fees has grown in recent

years. Many municipalities try to encourage homeowners and developers to incorporate green

infrastructure practices by offering incentives. The most common types of local incentive

mechanisms are stormwater fee discounts or credits, development incentives, rebates or

financing for installation of specific practices, and award and recognition programs.

The Environmental Protection Agency’s (EPA’s) interest in and support for green

infrastructure has grown since the 1990s. The agency has provided technical assistance and

information and developed policies to facilitate and encourage green infrastructure solutions and

incorporation in Clean Water Act permits. Pressed by municipalities about the challenges and

costs that they face in addressing needs for wastewater and stormwater projects, in 2012 EPA

issued an integrated permitting and planning framework for water infrastructure projects. The

intention of the framework document is to provide communities with flexibility to prioritize

needed water infrastructure investments. One component of the framework is identifying green

infrastructure opportunities. EPA also is working with communities to refine how the agency

determines when an infrastructure project is affordable for individual communities.

Cohen, P., et al. (2014). "The impact of an urban park on air pollution and noise levels in

the Mediterranean city of Tel-Aviv, Israel." Environmental Pollution 195: 73-83.

This study examines the influence of urban parks on air quality and noise in the city of

Tel-Aviv, Israel, by investigation of an urban park, an urban square and a street canyon.

Simultaneous monitoring of several air pollutants and noise levels were conducted. The results

showed that urban parks can reduce NOx, CO and PM10 and increase O3 concentrations and that

park's mitigation effect is greater at higher NOx and PM10 levels. During extreme events, mean

values of 413ppb NOx and 80 μG/m3 PM10 were measured in the street while mean values of

89ppb NOx and 24 μG/m3 PM10 were measured in the park. Whereas summer highest O3

values of 84ppb were measured in the street, 94ppb were measured in the park. The benefit of

the urban park in reducing NOx and PM10 concentrations is more significant than the

disadvantage of increased O3 levels. Furthermore, urban parks can reduce noise by ∼5 dB(A).

Clapp, J. C., et al. (2014). "Rationale for the increased use of conifers as functional green

infrastructure: A literature review and synthesis." Arboricultural Journal 36(3): 161-178.

Green infrastructure is the aggregate of plants and green spaces in the urban landscape.

This infrastructure provides many benefits that are becoming increasingly valuable as

municipalities strive for urban sustainability. The value of the urban forest is an integral part of

securing funding and support for urban forestry initiatives: the higher the value the more support

is gained, and benefits accrued. According to available data from street tree inventories, most

species that make up street trees in urban forests in the United States and Canada are broadleaf,

deciduous species. Since many urban tree benefits are attributed to the tree canopies, benefits

effectively drop to negligible levels during the leaf-off period. When a rain event occurs during

this season, the canopy cover afforded by evergreen tree species, in concert with the canopy

architecture and density of evergreen conifers will help to maintain canopy-dependent benefits.

This paper investigates the role that conifers play in increasing the canopy-dependent ecosystem

services of an urban forest and the unique role they play in increasing the stability of the urban

forest through diversification.

Chong, K. Y., et al. (2014). "Not all green is as good: Different effects of the natural and

cultivated components of urban vegetation on bird and butterfly diversity." Biological

Conservation 171: 299-309.

It has been suggested that provision of greenery can ameliorate the hostility of the urban

environment for wildlife, but greenery can either be in the form of regenerating or remnant

patches of natural vegetation, or as cultivated tree, shrub, and ground cover. We test if natural

and cultivated greenery differed in their effects on bird and butterfly diversity in the tropical city-

state of Singapore, while accounting for the effects of traffic density. Natural vegetation cover

was positively correlated to both bird and butterfly species richness. Cultivated tree cover was

positively correlated to bird species richness. Meanwhile, ground cover was weakly negatively

correlated to bird species richness and overall cultivated greenery cover was weakly positively

correlated to butterfly species richness. Increasing road lane density also negatively impacted

both bird and butterfly species richness, while there was substantial evidence for an interaction

effect between road lane density and cultivated tree cover on bird species richness. Cultivated

and natural forms of greenery favoured different assemblages of bird and butterfly species. After

controlling for the confounding effects of alpha diversity on community dissimilarity, cultivated

greenery was found to produce homogeneous bird and butterfly communities in the urban

landscape. Therefore, not all forms of greenery benefit urban biodiversity to the same extent.

Management of urban areas to support bird and butterfly wildlife would need to maximise

natural or semi-natural cover and only resort to highly-manicured, artificial greenery as a second

option, while planning road networks carefully to optimize road lane density.

Brantley, H. L., et al. (2014). "Field assessment of the effects of roadside vegetation on

near-road black carbon and particulate matter." Sci Total Environ 468.

One proposed method for reducing exposure to mobile source air pollution is the

construction or preservation of vegetation barriers between major roads and nearby populations.

This study combined stationary and mobile monitoring approaches to determine the effects of an

existing, mixed-species tree stand on near-road black carbon (BC) and particulate matter

concentrations. Results indicated that wind direction and time of day significantly affected

pollutant concentrations behind the tree stand. Continuous sampling revealed reductions in BC

behind the barrier, relative to a clearing, during downwind (12.4% lower) and parallel (7.8%

lower) wind conditions, with maximum reductions of 22% during the late afternoon when winds

were from the road. Particle counts in the fine and coarse particle size range (0.5–10 μm

aerodynamic diameter) did not show change. Mobile sampling revealed BC concentration

attenuation, a result of the natural dilution and mixing that occur with transport from the road,

was more gradual behind the vegetation barrier than in unobstructed areas. These findings

suggest that a mature tree stand can modestly improve traffic-related air pollution in areas

located adjacent to the road; however, the configuration of the tree stand can influence the

likelihood and extent of pollutant reductions.

Berland, A. and M. E. Hopton (2014). "Comparing street tree assemblages and associated

stormwater benefits among communities in metropolitan Cincinnati, Ohio, USA." Urban

Forestry & Urban Greening 13(4): 734-741.

Green infrastructure approaches leverage vegetation and soil to improve environmental

quality. Municipal street trees are crucial components of urban green infrastructure because they

provide stormwater interception benefits and other ecosystem services. Thus, it is important to

understand the patterns and drivers of structural heterogeneity in urban street tree assemblages.

In this study, we compared the forest structure of street trees across nine communities along both

geographic and demographic gradients in metropolitan Cincinnati, Ohio, USA. Specifically, we

used a two-part statistical model to compare both the proportion of sampled street segments

containing zero trees, and basal area magnitude for street segments with trees. We made

community-scale comparisons based on street tree management, socioeconomics, and

geographic setting. Then, using modeled stormwater interception estimates from i-Tree Streets,

we investigated the implications of heterogeneity in street tree assemblages for stormwater

interception benefits. The forest structure of street trees varied across communities in relation to

management practices, namely participation in the Tree City USA program. As a consequence of

this structural difference, we observed a stark discrepancy in estimated stormwater interception

between Tree City USA participants (128.7 m3/km street length) and non-participants (59.2

m3/km street length). While street tree assemblages did not vary by community poverty status,

we did find differences according to community racial composition. In contrast to previous

research, basal area was greater in predominantly black (i.e., African American) and racially

mixed communities than in predominantly white communities. We did not observe structural

differences across geographic strata. This research underscores the importance of proactive

management practices for increasing the forest structure of street trees. Our findings regarding

socioeconomics and geographic setting contrast previous studies, suggesting the need for

continued research into the drivers of structural heterogeneity in street tree assemblages.

Berardi, U., et al. (2014). "State-of-the-art analysis of the environmental benefits of green

roofs." Applied Energy 115: 411-428.

Green roofs have been proposed for sustainable buildings in many countries with

different climatic conditions. A state-of-the-art review of green roofs emphasizing current

implementations, technologies, and benefits is presented in this paper. Technical and

construction aspects of green roofs are used to classify different systems. Environmental benefits

are then discussed mainly by examining measured performances. By reviewing the benefits

related to the reduction of building energy consumption, mitigation of urban heat island effect,

improvement of air pollution, water management, increase of sound insulation, and ecological

preservation, this paper shows how green roofs may contribute to more sustainable buildings and

cities. However, an efficient integration of green roofs needs to take into account both the

specific climatic conditions and the characteristics of the buildings. Economic considerations

related to the life-cycle cost of green roofs are presented together with policies promoting green

roofs worldwide. Findings indicate the undeniable environmental benefits of green roofs and

their economic feasibility. Likewise, new policies for promoting green roofs show the necessity

for incentivizing programs. Future research lines are recommended and the necessity of cross-

disciplinary studies is stressed.

Baró, F., et al. (2014). "Contribution of Ecosystem Services to Air Quality and Climate

Change Mitigation Policies: The Case of Urban Forests in Barcelona, Spain." AMBIO

43(4): 466-479.

Mounting research highlights the contribution of ecosystem services provided by urban

forests to quality of life in cities, yet these services are rarely explicitly considered in

environmental policy targets. We quantify regulating services provided by urban forests and

evaluate their contribution to comply with policy targets of air quality and climate change

mitigation in the municipality of Barcelona, Spain. We apply the i-Tree Eco model to quantify in

biophysical and monetary terms the ecosystem services “air purification,” “global climate

regulation,” and the ecosystem disservice “air pollution” associated with biogenic emissions. Our

results show that the contribution of urban forests regulating services to abate pollution is

substantial in absolute terms, yet modest when compared to overall city levels of air pollution

and GHG emissions. We conclude that in order to be effective, green infrastructure-based efforts

to offset urban pollution at the municipal level have to be coordinated with territorial policies at

broader spatial scales.

Baldauf, R. and D. Nowak (2014). Vegetation and Other Development Options for

Mitigating Urban Air Pollution Impacts. Global Environmental Change. B. Freedman.

Dordrecht, Springer Netherlands: 479-485.

Emission control techniques and programs that reduce air pollution are an important

component of air quality management strategies; however, options that directly remove pollution

or reduce exposures also exist that can further mitigate the impacts of air pollution in urban

areas. These methods can complement existing pollution control programs or provide measures

to minimize impacts from sources difficult to mitigate. Since air pollution control techniques,

emission standards, and urban planning strategies to reduce urban air pollution impacts are

discussed in other sections of this handbook, this section focuses on options that developers,

transportation designers, and urban planners can implement to reduce concentra- tions and

population exposures to harmful air contaminants.

Andersson, E., et al. (2014). "Reconnecting Cities to the Biosphere: Stewardship of Green

Infrastructure and Urban Ecosystem Services." AMBIO 43(4): 445-453.

Within-city green infrastructure can offer opportunities and new contexts for people to

become stewards of ecosystem services. We analyze cities as social–ecological systems,

synthesize the literature, and provide examples from more than 15 years of research in the

Stockholm urban region, Sweden. The social–ecological approach spans from investigating

ecosystem properties to the social frameworks and personal values that drive and shape human

interactions with nature. Key findings demonstrate that urban ecosystem services are generated

by social–ecological systems and that local stewards are critically important. However, land-use

planning and management seldom account for their role in the generation of urban ecosystem

services. While the small scale patchwork of land uses in cities stimulates intense interactions

across borders much focus is still on individual patches. The results highlight the importance and

complexity of stewardship of urban biodiversity and ecosystem services and of the planning and

governance of urban green infrastructure.

Zhang, H., et al. (2013). "Isolation and Identification of Toluene-Metabolizing Bacteria

from Rhizospheres of Two Indoor Plants." Water, Air, & Soil Pollution 224(9).

The role of the rhizosphere microbial commu- nity in removing volatile organic

compounds has not been well investigated. In this study, two species of indoor foliage plants,

Fittonia verschaffeltii var. argyroneura and Hoya carnosa, were primed with toluene exposure for

2 months, followed by isolation and identification of the rhizosphere bacteria that were

demonstrated to metab- olize toluene. A total of 42 bacterial isolates were obtained. The number

of bacterial isolates was narrowed down to 23, which had banding pattern similarities of 80 % or

less, using BOX-polymerase chain reaction (PCR) fingerprint- ing technique. The 23 isolates

were further characterized by sequencing part of their 16S rDNA after PCR. Their identities

were examined using Basic Local Alignment Search Tool (BLAST), resulting in the isolates

having the highest sequence similarities (97–100 %) to eight known bacteria strains, none of

which had been previously report- ed to be capable of degrading toluene. The bacterial iso- lates

were positive for toluene monooxygenase gene, confirming their genetic potential to metabolize

toluene. Five of the isolates were further tested with 14C-labeled toluene to directly show their

ability to metabolize toluene. Isolate type did not significantly affect the percent of toluene

mineralized over 2 weeks' time. However, the iso- lates had differing response to varying toluene

concentra- tions. Under low (0.05) and high (0.2 μCi/mL) concentra- tions, they mineralized 43

and 49 % of toluene, respec- tively. The isolation and characterization of toluene- metabolizing

bacteria corroborates previous speculation that the rhizosphere microbial community contributes

to the phytoremediation potential of indoor foliage plants.

Yang, B. and S. Li (2013). "Green infrastructure design for stormwater runoff and water

quality: Empirical evidence from large watershed-scale community developments." Water

5(4): 2038-2057.

Green infrastructure (GI) design is advocated as a new paradigm for stormwater

management, whereas current knowledge of GI design is mostly based on isolated design

strategies used at small-scale sites. This study presents empirical findings from two watershed-

scale community projects (89.4 km2 and 55.7 km2) in suburban Houston, Texas. The GI

development integrates a suite of on-site, infiltration-based stormwater management designs, and

an adjacent community development follows conventional drainage design. Parcel data were

used to estimate the site impervious cover area. Observed streamflow and water quality data (i.e.,

NO3-N, NH3-N, and TP) were correlated with the site imperviousness. Results show that, as of

2009, the impervious cover percentage in the GI site (32.3%) is more than twice that of the

conventional site (13.7%). However, the GI site’s precipitation-streamflow ratio maintains a

steady, low range, whereas this ratio fluctuates substantially in the conventional site, suggesting

a “flashy” stream condition. Furthermore, in the conventional site, annual nutrient loadings are

significantly correlated with its impervious cover percentage (p < 0.01), whereas in the GI site

there is little correlation. The study concludes that integrated GI design can be effective in

stormwater runoff reduction and water quality enhancement at watershed-scale community

development.

Wen, M., et al. (2013). "Spatial Disparities in the Distribution of Parks and Green Spaces

in the USA." Annals of Behavioral Medicine 45(1): 18-27.

Background: Little national evidence is available on spatial disparities in distributions of

parks and green spaces in the USA.

Purpose: This study examines ecological associations of spatial access to parks and green

spaces with percentages of black, Hispanic, and low-income residents across the urban–rural

continuum in the conterminous USA.

Methods: Census tract-level park and green space data were linked with data from the

2010 U.S. Census and 2006–2010 American Community Surveys. Linear mixed regression

models were performed to examine these associations.

Results: Poverty levels were negatively associated with distances to parks and

percentages of green spaces in urban/suburban areas while positively associated in rural areas.

Percentages of blacks and Hispanics were in general negatively linked to distances to parks and

green space coverage along the urban–rural spectrum.

Conclusions: Place-based race–ethnicity and poverty are important correlates of spatial

access to parks and green spaces, but the associations vary across the urbanization levels.

Vos, P. E. J., et al. (2013). "Improving local air quality in cities: To tree or not to tree?"

Environ Pollut 183.

Vegetation is often quoted as an effective measure to mitigate urban air quality problems.

In this work we demonstrate by the use of computer models that the air quality effect of urban

vegetation is more complex than implied by such general assumptions. By modelling a variety of

real-life examples we show that roadside urban vegetation rather leads to increased pollutant

concentrations than it improves the air quality, at least locally. This can be explained by the fact

that trees and other types of vegetation reduce the ventilation that is responsible for diluting the

traffic emitted pollutants. This aerodynamic effect is shown to be much stronger than the

pollutant removal capacity of vegetation. Although the modelling results may be subject to a

certain level of uncertainty, our results strongly indicate that the use of urban vegetation for

alleviating a local air pollution hotspot is not expected to be a viable solution.

Valderrama, A., et al. (2013). "Creating Clean Water Cash Flows Developing Private

Markets for Green Stormwater Infrastructure in Philadelphia." Natural Resources

Defense Council. Philadelphia, Pennsylvania.

When rainwater rushes off Philadelphia’s buildings and other impervious structures, it

strains the city’s combined sewer system, causing approximately 13 billion gallons of untreated

sewage mixed with polluted runoff to over ow into city waterways each year. Philadelphia’s

expansive stormwater runoff problem is no anomaly. It is one of nearly 800 communities

nationwide that are required by the Clean Water Act to reduce raw sewage over ows from

combined sewer systems, and thousands more have obligations to reduce pollution from separate

storm sewer systems. Philadelphia is also one of many cities nationwide that is increasingly

turning to green infrastructure solutions as a key part of the stormwater runoff solution. Green

infrastructure includes installations such as rain gardens, swales, and green roofs, which capture

runoff from impervious cover before it reaches overburdened sewer systems.

Vailshery, L. S., et al. (2013). "Effect of street trees on microclimate and air pollution in a

tropical city." Urban Forestry Urban Greening 12.

One of the fastest growing cities in India, Bangalore is facing challenges of urban

microclimate change and increasing levels of air pollution. This paper assesses the impact of

street trees in mitigating these issues. At twenty locations in the city, we compare segments of

roads with and without trees, assessing the relationship of environmental differences with the

presence or absence of street tree cover. Street segments with trees had on average lower

temperature, humidity and pollution, with afternoon ambient air temperatures lower by as much

as 5.6 °C, road surface temperatures lower by as much as 27.5 °C, and SO2 levels reduced by as

much as 65%. Suspended Particulate Matter (SPM) levels were very high on exposed roads, with

50% of the roads showing levels approaching twice the permissible limits, while 80% of the

street segments with trees had SPM levels within prescribed limits. In an era of exacerbated

urbanization and climate change, tropical cities such as Bangalore will have to face some of the

worst impacts including air pollution and microclimatic alterations. The information generated in

this study can help appropriately assess the environmental benefits provided by urban trees,

providing useful inputs for urban planners.

Terzaghi, E., et al. (2013). "Forest Filter Effect: Role of leaves in capturing/releasing air

particulate matter and its associated PAHs." Atmospheric Environment 74: 378-384.

Plants play a key role in removing particulate matter and their associated Semi-volatile

Organic Compounds (SVOCs) from the atmosphere. Understanding the processes involved in

particle capture by vegetation is essential to understand the interactions between SVOCs,

particles and plants. In the present study Two Photon Excitation Microscopy (TPEM) was used

to visualise particle matter uptake and encapsulation, together with its distribution on leaf/needle

surface of different broadleaf (cornel and maple) and conifer species (stone pine). Phenanthrene

accumulation, the number of particles associated with this compound and its migration from

particles into the leaf cuticle was also identified and quantified. Species-specific deposition

velocities were estimated to model temporal PM10 leaf/needle accumulation and to investigate

the role of Planet Boundary Layer (PBL) height variation in influencing PM10 flux to plants.

Particles at the leaf/needle surface were visualised to range in size from 0.2 to 70.4 μm, but

cuticular encapsulation was negligible for particles larger than 10.6 μm, which were removed by

a washing procedure. Phenanthrene concentration varied between ≈5 and ≈10 ng g−1 dw

according to plant species and between ≈10 and ≈200 ng g−1 dw depending on needle age; this

compound was visualized to migrate from particles into the adjacent leaf cuticle. Species-

specific deposition velocity range between 0.57 and 1.28 m h−1 and preliminary simulations

showed that the diel variability of PBL structure influenced the temporal PM10 flux and

leaf/needle concentration, e.g. during daytime hours characterized by high PBL height, PM10

accumulated on cornel leaves was about 65% lower than the amount accumulated during night

time. The capability of vegetation to capture particles from the atmosphere, retain, encapsulate

them into the cuticle and release them to soil and/or lower biomass, highlighted the value of

vegetation in removing pollutants from the atmosphere and influencing their environmental fate.

Strohbach, M. W., et al. (2013). "Are small greening areas enhancing bird diversity?

Insights from community-driven greening projects in Boston." Landscape and Urban

Planning 114: 69-79.

Green space is an important component of the urban landscape, providing ecosystem

services for city dwellers and supporting biodiversity. In many cities, green space is concentrated

in large areas, while the rest is dispersed in small patches like pocket parks, gardens or street

trees. Such small-scale green space is often the target of greening initiatives but little is known

about their value for supporting and conserving biodiversity. To assess the value of such

initiatives for biodiversity, we used birds as an indicator. We examined bird communities at

small greening projects (n = 12), nearby randomly chosen urban sites (n = 12), and large parks (n

= 6) in Boston, MA, in relationship to underlying landscape patterns. Our results show that large

parks harbor a distinct and rich bird community. The other sites, regardless of the presence of

greening projects, were very similar to each other. However, most sites with greening projects

had higher species richness than the random urban site in their vicinity. The main factor

associated with this appears to be the patch size of green space and to a lesser extent, tree

cavities. Even small increases of a few hundred square meters were associated with an increase

in bird richness. Having more trees with cavities was also beneficial for species richness. Small

greening projects appear to be most valuable for urban biodiversity if they target preserving,

increasing and connecting existing green space. This may represent a tradeoff with

environmental justice criteria for new green space.

Soreanu, G., et al. (2013). "Botanical biofiltration of indoor gaseous pollutants – A mini-

review." Chemical Engineering Journal 229: 585-594.

In the last decade, indoor air pollution has been unanimously recognised as a public

health hazard worldwide, both in developed and developing countries. Accumulation of indoor

air pollutants appears to significantly contribute to “sick building syndrome” (SBS) and other

reported diseases in affected spaces. Botanical biofiltration has received a great deal of attention

in the past decade, likely due its economical, environmental and social benefits, including its

potential in the near future to be incorporated in both traditional and the new trend of sustainable

zero-emission green buildings. This paper focuses on the potential and challenges of using

botanical biofiltration for reducing the impact of gaseous pollutants in indoor environments. It is

aimed at reviewing the current state of the art and the future research needs.

Sinicina, N., et al. (2013). "Impact of microclimate and indoor plants on air ion

concentration." Vide. Tehnologija. Resursi - Environment, Technology, Resources 1: 66-72.

Saturation of air ions is essentially important for all living beings, especially for human

health. Existing sanitary norms provide that concentration of small ions has to be in range of

400-50000 ions cm-3 and unipolarity coefficient 0.4 ≤ K ≤ 1.0. Many species of indoor plants

emit organic volatile compounds and air ions, therefore they could be used for improving the

quality of indoor air. The results show that ionization level of indoor air is significantly

insufficient and selected species of indoor plants are not able to improve it. They serve rather as

supplementary surfaces for ion absorption. Possible interaction between microclimate, ion

concentration and indoor plants in different times of the day is analyzed.

Silvera Seamans, G. (2013). "Mainstreaming the environmental benefits of street trees."

Urban Forestry & Urban Greening 12(1): 2-11.

Over the course of the last three decades the role of the street tree in planning and policy

arenas has transitioned from one primarily of beautification and ornamentation to one more

inclusive of environmental services provision in numerous U.S. cities. This phenomenon was

examined in the northern California cities of Palo Alto, Sacramento, and San Francisco. Analysis

of policy documents, non-profit newsletters, field work, and interviews revealed that claims

about the environmental values of street trees have been championed by municipal and non-

profit actors and have been legitimized by the production and dissemination of urban forest

science.

Schubert, S. and S. Grossman-Clarke (2013). "The influence of green areas and roof

albedos on air temperatures during Extreme Heat Events in Berlin, Germany."

Meteorologische Zeitschrift 22.

The mesoscale atmospheric model COSMO-CLM (CCLM) with the Double Canyon

Effect Parametrization Scheme (DCEP) is applied to investigate possible adaption measures to

extreme heat events (EHEs) for the city of Berlin, Germany. The emphasis is on the effects of a

modified urban vegetation cover and roof albedo on near-surface air temperatures. Five EHEs

with a duration of 5 days or more are identified for the period 2000 to 2009. A reference

simulation is carried out for each EHE with current vegetation cover, roof albedo and urban

canopy parameters (UCPs), and is evaluated with temperature observations from weather stations

in Berlin and its surroundings. The derivation of the UCPs from an impervious surface map and

a 3-D building data set is detailed. Characteristics of the simulated urban heat island for each

EHE are analysed in terms of these UCPs. In addition, six sensitivity runs are examined with a

modified vegetation cover of each urban grid cell by –25%, 5% and 15%, with a roof albedo

increased to 0.40 and 0.65, and with a combination of the largest vegetation cover and roof

albedo, respectively. At the weather stations' grid cells, the results show a maximum of the

average diurnal change in air temperature during each EHE of 0.82 K and –0.48 K for the –25%

and 15% vegetation covers, –0.50 K for the roof albedos of 0.65, and –0.63 K for the combined

vegetation and albedo case. The largest effects on the air temperature are detected during

midday.

Sawka, M., et al. (2013). "Growing summer energy conservation through residential tree

planting." Landscape and Urban Planning 113(0): 1-9.

Energy conservation strategies are now at the forefront of electrical utility demand-side

management planning. Residential shade trees extenuate the heating of buildings in the

summertime by intercepting insolation and by evapotranspirative cooling of their immediate

surroundings. By modifying location-specific climate data and tree growth characteristics, we

adapt the Sacramento Municipal Utility District's (SMUD) Tree Benefits Estimator for

application in Toronto, Canada. We then use our tool to model the air conditioning energy

conservation savings delivered by 577 trees planted in Toronto backyards between 1997 and

2000. In urban residential neighbourhoods, where houses are closely spaced, the energy

conservation benefits of planting a tree depend on species, on pre-existing canopy, and on

placement of the tree with respect to distance and orientation from buildings. Study trees

contributed 77,140 kWh (167 kWh/tree) of electricity savings as of 2009, 54.4% of which was

due to shading of neighbouring houses. Twenty-five years following planting, we estimate that

each study tree will have delivered, on average, between 435 and 483 kWh in energy

conservation benefit. Our findings indicate that residential tree-planting programmes in densely

settled urban areas should not focus exclusively on location-driven strategic planting to yield

large energy conservation benefits. Instead, we argue that priority should be given to selecting

planting locations that will maximize tree survival as neighbourhood energy conservation

benefits of a tree that achieves mature stature often outweigh the homeowner-specific benefits of

a strategically planted tree.

Salmond JA, W. D., Laing G, Kingham S, Dirks KN, Longley I, et al. (2013). The influence

of vegetation on the horizontal and vertical distribution of pollutants in a street canyon.

Space constraints in cities mean that there are only limited opportunities for increasing

tree density within existing urban fabric and it is unclear whether the net effect of increased

vegetation in street canyons is beneficial or detrimental to urban air quality at local scales. This

paper presents data from a field study undertaken in Auckland, New Zealand designed to

determine the local impact of a deciduous tree canopy on the distribution of the oxides of

nitrogen within a street canyon. The results showed that the presence of leaves on the trees had a

marked impact on the transport of pollutants and led to a net accumulation of pollutants in the

canyon below the tree tops. The incidence and magnitude of temporally localised spikes in

pollutant concentration were reduced within the tree canopy itself. A significant difference in

pollutant concentrations with height was not observed when leaves were absent. Analysis of the

trends in concentration associated with different wind directions showed a smaller difference

between windward and leeward sides when leaves were on the trees. A small relative increase in

concentrations on the leeward side was observed during leaf-on relative to leaf-off conditions as

predicted by previous modelling studies. However the expected reduction in concentrations on

the windward side was not observed. The results suggest that the presence of leaves on the trees

reduces the upwards transport of fresh vehicle emissions, increases the storage of pollutants

within the canopy space and reduces the penetration of clean air downwards from aloft.

Differences observed between NO and NO2 concentrations could not be accounted for by

dispersion processes alone, suggesting that there may also be some changes in the chemistry of

the atmosphere associated with the presence of leaves on the trees.

Rouse, D. C. and I. F. Bunster-Ossa (2013). Green infrastructure: a landscape approach.

This report provides an overview of green infrastructure and the role of landscape in

urban planning and design. Case studies from around the U.S. provide examples of integrating

green infrastructure with traditional urban infrastructure and best management practices. The

appendix includes a model regulatory framework.

Radford, K. G. and P. James (2013). "Changes in the value of ecosystem services along a

rural–urban gradient: A case study of Greater Manchester, UK." Landscape and Urban

Planning 109(1): 117-127.

The degradation and loss of vital ecosystem functions and services have been an

uncontested result of urbanisation. An understanding of how ecosystem services are provided

along rural–urban gradients is crucial in the task of conserving and enhancing vital services in

urban environments, increasing the quality of life of urban dwellers, and working towards a

sustainable future. Focusing on nine ecosystem services – aesthetic, spiritual, recreation, water

flow regulation, carbon sequestration, climate change adaptation, pollination, biodiversity

potential, and noise attenuation – regarded as important to urban areas the authors detail the

changes in the values of these services along a gradient comprising four categories of

urbanisation: urban, suburban, peri-urban and rural, in Greater Manchester, UK. The data on

which the discussion is based are derived from an interdisciplinary assessment tool, developed

from a selection of previously used assessment methods including the Residential Environment

Assessment Tool and the Green Flag Award. Based on a mixture of a field and desktop study,

the new tool assigns non-economic values of 0–10 to the selected services, allowing for

evaluation of quality between, as well as within, each category of ecosystem service. Trends in

the results are discussed, as are drivers for the changes in values along the rural–urban gradient.

It is foreseen that this new body of knowledge will allow both practitioners and academics to

gain further insight into the provision of ecosystem services along a rural–urban gradient to

allow them to tackle the problems associated with them and to optimise open space planning.

Pincetl, S., et al. (2013). "Urban tree planting programs, function or fashion? Los Angeles

and urban tree planting campaigns." GeoJournal 78(3): 475-493.

Tree planting programs are being implemented in many US cities (most notably New

York, Los Angeles, and Chicago) on the basis of the multiple environmental and health benefits

they may provide. However, the magnitude and even the direction of the impacts of trees on

specific urban environments have seldom been directly measured. In addition, there has been

little research on the historical, cultural, political or institutional origins of such programs, or on

their implementation process. Pending questions include the degree to which these programs are

integrated in the existing frameworks of city government and infrastructure management, how

they are paid for, and the kinds of collaborations between nonprofit organizations, the public,

and public agencies at all levels they may require in order to succeed. This paper reports on an

interdisciplinary research project examining the Million Tree Program of the City of Los

Angeles.

Peschardt, K. and U. Stigsdotter (2013). "Associations between park characteristics and

perceived restorativeness of small public urban green spaces." Landscape and Urban

Planning 112: 26-39.

Urban green space in dense city areas is a limited resource. However, previous research

indicates that such areas have a positive influence on mental restoration. As stress is a common

problem in cities, we test to see whether park characteristics are associated with the perceived

restorativeness of nine small public urban green spaces (SPUGS) in the dense city of

Copenhagen. Furthermore, we investigate whether there is a difference in preferences for park

characteristics amongst average users and the most stressed users of SPUGS. We conducted an

on-site questionnaire survey where respondents answered the perceived restorativeness scale

(PRS). All SPUGS were analysed using the eight perceived sensory dimensions (PSDs) which

describe different park characteristics. The analyses were conducted to see whether the PSDs

were present or not and to determine how strong or weak they were. For the first time the PRS

and the PSDs have been combined to see whether significant associations can be found between

park characteristics and the users' perceived restorativeness. First, seven of the eight PSDs could

be used in the study. Second, the PSDs 'social' and 'serene' were significantly associated with

average users' perceived restorativeness. And third, a difference between the users is that the

PSD 'nature' becomes important for the most stressed individuals. The results indicate that the

PSDs can be useful for the future analysis and design processes of SPUGS with the potential for

mental restoration. However, the PSDs need to be developed further to make them useful to

practitioners.

Peckham, S. C., et al. (2013). "Urban forest values in Canada: views of citizens in Calgary

and Halifax." Urban Forestry Urban Greening 12.

A significant component of the urban ecosystem is the urban forest. It is also the

quintessential meeting point of culture and nature, so it is critical to incorporate values-based

approaches to managing them. The values that really count are those of urban citizens. A novel

qualitative method was used to determine what qualities of the urban forest are valued by

citizens of Calgary, Alberta, and Halifax, Nova Scotia, Canada. These values were compared

with those reported in the literature to reveal that citizens value the urban forests mostly for their

non-material benefits. Specifically, urban forests contribute to human emotional, intellectual, and

moral fulfilment.

O’Donoghue, A. and C. M. Shackleton (2013). "Current and potential carbon stocks of

trees in urban parking lots in towns of the Eastern Cape, South Africa." Urban Forestry &

Urban Greening 12(4): 443-449.

Greening of shopping centre parking lots is a potentially important strategy that can

contribute to urban carbon mitigation efforts, improve aesthetics and the shopping experience of

consumers, whilst adding to urban biodiversity. Twenty-eight shopping centre parking lots in six

Eastern Cape urban centres, South Africa, were sampled to determine tree species composition,

density and annual carbon sequestration potential. The best case parking lot found during the

study was used as a benchmark to display the difference between current tree density and above-

ground carbon stocks relative to the potential optimum. The highest tree density was 66 trees

ha−1, whereas the average density across all sampled parking lots was less than half that (27.2 ±

22.6 trees ha−1). The average annual carbon sequestration potential per parking lot was 1390 ±

2503 kg ha−1. Planting density was positively related to annual sequestration rates, whilst

parking lot age and the mean annual rainfall of the town had no influence. Mean tree species

richness per parking lot was 2.3 ± 1.8 species, with a positive relationship to parking lot size, but

not to mean annual rainfall of the site. The majority of trees (62.5%) in parking lots were alien

species, although newer parking lots had significantly greater proportions of indigenous species.

There was no difference in mean annual carbon sequestration rate per tree between indigenous

and alien trees species. Low tree densities and small parking lot areas constrained the potential

for earning carbon credits from trees in parking lots. Nonetheless, planners and designers need to

be more aware of the potential contribution of trees towards urban sustainability.

McPherson, E. G., et al. (2013). "A new approach to quantify and map carbon stored,

sequestered and emissions avoided by urban forests." Landscape and Urban Planning 120:

70-84.

This paper describes the use of field surveys, biometric information for urban tree species

and remote sensing to quantify and map carbon (C) storage, sequestration and avoided emissions

from energy savings. Its primary contribution is methodological; the derivation and application

of urban tree canopy (UTC) based transfer functions (t C ha−1 UTC). Findings for Los Angeles

and Sacramento illustrate the complex role of regional and local determinants. Although average

tree density and size were substantially greater in Los Angeles, the mean C storage density (8.15

t ha−1) was 53 percent of Sacramento's (15.4 t ha−1). In Sacramento, native oaks with very high

wood densities (815 kg m−3) accounted for 30 percent of total basal area. In Los Angeles, the

most dominant taxa had relatively low wood densities (350-550 kg m−3). The inclusion of

relatively more wooded land in the Sacramento study area may partially explain higher C storage

levels. In Los Angeles, where development is relatively dense, 14 percent of all trees surveyed

shaded more than one building compared to only 2 percent in Sacramento. Consequently, the

transfer function for avoided emissions in Los Angeles (2.77 t ha−1 UTC yr−1) exceeded

Sacramento (2.72 t ha−1 UTC yr−1). The approach described here improves C estimates and

increases the resolution at which C can be mapped across a region. It can be used to map

baseline C storage levels for climate action planning, identify conservation areas where UTC

densities are highest and determine where opportunities for expanding UTC are greatest.

Maher, B. A., et al. (2013). "Impact of roadside tree lines on indoor concentrations of

traffic-derived particulate matter." Environmental Science & Technology 47(23): 13737-

13744.

Exposure to airborne particulate pollution is associated with premature mortality and a

range of inflammatory illnesses, linked to toxic components within the particulate matter (PM)

assemblage. The effectiveness of trees in reducing urban PM10 concentrations is intensely

debated. Modeling studies indicate PM10 reductions from as low as 1% to as high as ∼60%.

Empirical data, especially at the local scale, are rare. Here, we use conventional PM10

monitoring along with novel, inexpensive magnetic measurements of television screen swabs to

measure changes in PM10 concentrations inside a row of roadside houses, after temporarily

installing a curbside line of young birch trees. Independently, the two approaches identify >50%

reductions in measured PM levels inside those houses screened by the temporary tree line.

Electron microscopy analyses show that leaf- captured PM is concentrated in agglomerations

around leaf hairs and within the leaf microtopography. Iron-rich, ultrafine, spherical particles,

probably combustion-derived, are abundant, form a particular hazard to health, and likely

contribute much of the measured magnetic remanences. Leaf magnetic measurements show that

PM capture occurs on both the road-proximal and -distal sides of the trees. The efficacy of

roadside trees for mitigation of PM health hazard might be seriously underestimated in some

current atmospheric models.

Kessler, R. (2013). "Green walls could cut street-canyon air pollution." Environ Health

Perspect 121.

Rows of tall buildings can create a unique urban habitat known as a street canyon. These

canyons trap traffic pollutants, limiting their dispersal into the atmospheric boundary layer that

extends as high as 2,000 meters above the ground. A new study suggests that vegetation in street

canyons may reduce air-pollutant concentrations much more than previously reported and

suggests innovative planting configurations to improve city pollution hot spots.

Outdoor air pollution is believed to cause an estimated 1.3 million annual deaths

worldwide,2 as well as an increased risk of respiratory and cardiovascular diseases.3 Plantings

are often promoted as a partial solution, because leaves absorb gaseous pollutants through their

pores and capture particulate matter on their surfaces.4,5,6,7,8,9,10,11 Yet modeling studies of

the vegetation across entire cities have estimated that existing green cover reduces air pollution

concentrations by less than 1.5%.

Keeley, M., et al. (2013). "Perspectives on the Use of Green Infrastructure for Stormwater

Management in Cleveland and Milwaukee." Environmental Management 51(6): 1093-1108.

Green infrastructure is a general term referring to the management of landscapes in ways

that generate human and ecosystem benefits. Many municipalities have begun to utilize green

infrastructure in efforts to meet stormwater management goals. This study examines challenges

to integrating gray and green infrastructure for stormwater management, informed by interviews

with practitioners in Cleveland, OH and Milwaukee WI. Green infrastructure in these cities is

utilized under conditions of extreme fiscal austerity and its use presents opportunities to connect

stormwater management with urban revitalization and economic recovery while planning for the

effects of negative- or zero-population growth. In this context, specific challenges in capturing

the multiple benefits of green infrastructure exist because the projects required to meet federally

mandated stormwater management targets and the needs of urban redevelopment frequently

differ in scale and location.

Jones, R. E., et al. (2013). "The Value of Trees." Environment and Behavior 45(5): 650-676.

The article discusses the value and importance of urban trees and factors that

significantly influence public support for protecting them. These factors were identified by

examining mail survey data obtained from a representative sample of 800 homeowners living in

a rapidly urbanizing area within Southern Appalachia. A series of multiple regression analysis

tested an Integrated Model of Urban Tree Support that combines measures of attitudes, beliefs,

values, and sociodemographic variables to predict homeowner support for local urban tree

protection. The findings lend support to many features of the model and revealed that

homeowners who have stronger protree attitudes, have greater environmental concerns, place

more importance on trees when looking for a new place to live, attribute symbolic value and

meaning to them are more supportive. Women and Democrats are also more supportive.

Recommendations are offered for future research and policy.

Irga, P. J., et al. (2013). "Can hydroculture be used to enhance the performance of indoor

plants for the removal of air pollutants?" Atmospheric Environment 77: 267-271.

The indoor plant, Syngonium podophyllum, grown in both conventional potting mix and

hydroculture, was investigated for its capacity to reduce two components of indoor air pollution;

volatile organic compounds (VOCs) and CO2. It was found that, with a moderate increase in

indoor light intensity, this species removed significant amounts of CO2 from test chambers,

removing up to 61% ± 2.2 of 1000 ppmv over a 40 min period. It was also found that the

hydroculture growth medium facilitated increased CO2 removal over potting mix. The VOC

removing potential of hydroculture plants was also demonstrated. Whilst the rate of VOC

(benzene) removal was slightly lower for hydroculture-grown plants than those grown in potting

mix, both removed 25 ppmv from the test chambers within 7 days. The effect of benzene on the

community level physiological profiles of rhizospheric bacteria was also assessed. There was

less variability in the carbon substrate utilisation profile of the bacterial community from the

rhizosphere of hydroculture plants compared to potting mix, however the species present

encompassed at least those involved with VOC removal. Overall, we propose that plants grown

in hydroculture can simultaneously deplete CO2 and VOCs, and thus may have potential for

improving indoor air quality.

Hubacek, K. and J. Kronenberg (2013). "Synthesizing different perspectives on the value of

urban ecosystem services." Landscape and Urban Planning 109(1): 1-6.

Since 2008 more than half of the world population lives in cities and within the next 40

years the share of urban dwellers is estimated to increase to 70%. Urban populations do not only

use ecosystem services from outside urban boundaries (clearly their ecological footprints are

much larger than their physical areas) but, often unknowingly, they also rely on urban

ecosystems. While researchers primarily focus on distant ecosystems, crucial for the preservation

of life on the planet, most local ecosystems in and around urban areas suffer from an increasing

pressure from further urbanization and growing consumption within cities. Important urban

ecosystem services are often being neglected without the understanding of their importance and

value. Meanwhile, they are crucial for the sustainability of life and the wellbeing of residents in

urban areas.

Attempts have been made to highlight the value of urban ecosystem services, especially

with reference to urban greenery, water and allotment gardens. Different perspectives on the

value of urban ecosystem services have been revealed, including economic (benefits and

savings), socio-ecological (resilience), psychological (well-being), cultural (e.g. inspiration), and

philosophical or ethical. On the one hand, such a multitude of perspectives suggests that at least

some of these perspectives should be meaningful to different groups of stakeholders. On the

other hand, ultimately, this variety might weaken the message delivered to decision-makers who

often only follow narrow economic reasoning. The objective of this seminar and the special issue

of Landscape and Urban Planning that follows is to bring together the various perspectives on

the value of urban ecosystem services and discuss the potential of merging and synthesizing

these perspectives. Ultimately, this should lay foundations for a more sustainable management of

ecosystem services in urban areas.

Haviland-Jones, J., et al. (2013). "The emotional air in your space: Scrubbed, wild or

cultivated?" Emotion, Space and Society 6: 91-99.

The space around or in our buildings is not empty but is full of air. This air naturally

contains some potential toxins but also useful biochemicals that we are not aware of; t however,

our olfactory system has evolved to detect some of them subliminally. Conscious preferences for

or against types of air may be insufficient for decisions about the desirability of natural, green

air. It is a 21st challenge to “green technology” to extend and incorporate behavioral science

approaches to understanding influential subliminal processes. We argue that these decisions

require an experimental approach because the olfactory system is not easily accessible to

conscious analysis. The subliminal effects of “something in the air” are illustrated first in a case

study to show the surprising range of emotional effects from natural human mood odors. Then in

a controlled study we show some similar subliminal effects from natural plant odors. Here

“wild” local air is contrasted with two types of “cultivated” air, either with undetected (a) flower

ingredients or (b) perfume ingredients. The subliminal effect of the floral additive led to more

positive emotional thought and supported social approach behavior. This implies air management

has the potential to provide an invisible support system inside and around buildings just as

carefully designed and maintained parks provide a larger support to communities.

Gómez-Baggethun, E., et al. (2013). Urban ecosystem services. Urbanization, biodiversity

and ecosystem services: challenges and opportunities: a global assessment. T. Elmqvist, M.

Fragkias, J. Goodness et al. Dordretch, Springer.

We explore the potential of urban ecosystem services for improving resilience and quality

of life in cities. First, we classify and categorize important ecosystem services and disservices in

urban areas. Second, we describe a range of valuation approaches (cultural values, health

benefits, economic costs, and resilience) for capturing the importance of urban ecosystem service

multiple values. Finally, we analyze how ecosystem service assessment may inform urban

planning and governance and provide practical examples from cities in Africa, Europe, and

America. From our review, we find that many urban ecosystem services have already been

identified, characterized and valued, and have been found to be of great value and importance for

human well-being and urban resilience. We conclude that the use of the concept of urban

ecosystem services can play a critical role in reconnecting cities to the biosphere, and reducing

the ecological footprint and ecological debt of cities while enhancing resilience, health, and

quality of life of their inhabitants.

Gago, E. J., et al. (2013). "The city and urban heat islands: A review of strategies to

mitigate adverse effects." Renewable and Sustainable Energy Reviews 25: 749-758.

Cities occupy 2% of the earth's surface but their inhabitants consume 75% of the world's

energy resources. Under certain conditions, the heat from solar radiation and different urban

activities can make city temperatures rise in certain areas, simply because of the way in which a

city is structured. This effect is known as the urban heat island (UHI). This article provides a

review of recent research on the urban heat island as well as of the strategies that can be applied

to mitigate its adverse effects. Such strategies can be applied in the project design phase of urban

planning and thus directly affect city temperatures on a local scale. The elements analyzed in this

paper include green spaces, trees, albedo, pavement surfaces, vegetation, as well as building

types and materials. The discussion of this research clearly reflects the impact of urban

morphology on local temperatures and how urban design can be modified to reduce energy

consumption and CO2 emissions into the atmosphere. This study is useful for professionals who

are responsible for decision-making during the design phase of urban planning.

Farrugia, S., et al. (2013). "An evaluation of flood control and urban cooling ecosystem

services delivered by urban green infrastructure." International Journal of Biodiversity

Science, Ecosystem Services & Management 9(2): 136-145.

To inform planning decisions and address climate change impacts in expanding cities, it

is desirable to quantify urban ecosystem services like flood control and urban cooling. By

comparing with a purpose-built habitat map, this study ground-truthed a method to assess flood

control, which was developed by Southampton City Council from surface maps. It was

confirmed that infiltration capacity is a good proxy for flood control, leaf area index could

represent urban cooling, and thereby both could be used to score urban surface types. A two-

tiered system was proposed so that surface maps would be used for city-wide scale, and as they

produce similar results that are more accurate at fine scales, habitat maps are used at site level.

These surrogates were integrated to produce a Green Space Factor for flood control and urban

cooling, wherein a combined score can be generated for particular locations. This could be

extended further to include other ecosystem services. The new integrated multi-scale ecosystem

service quantification tool could be used by developers and policy-makers to identify target areas

in their projects and policies that could benefit from enhanced green infrastructure.

Farmer, M. C., et al. (2013). "Bird diversity indicates ecological value in urban home

prices." Urban Ecosystems 16(1): 131-144.

It is known that public greenspaces contribute positively to urban home prices; yet urban

ecologists also have known that not all greenspaces are equally valuable. Also some ecologically

valuable space appears on private residences, not only public spaces. This work examines

directly whether using a variable derived from bird species richness and relative abundance adds

new information regarding ecological value and if high values of that variable significantly

improve urban housing prices. We collected information on approximately 368 home sales in

Lubbock, TX from 2008 to 2009 from the Multiple Listing Service: Sale Price, Square Footage,

Lot Size and Age in 17 neighborhoods identified by the Lubbock Realtor Association. We

conducted bird counts in the vicinity of each home sale and recorded both the total numbers of

birds and the number of bird species identified in a particular class—less ubiquitous bird species.

Finally, we used GIS to record the percentage of tree cover in the immediate area surrounding

each sale. We constructed a predictive model for a bird relative abundance and species richness

variable (Bird) from AICc statistics. Home price for each sale then was regressed against the

predicted value of ‘Bird’ from the selected model and regressed against home price along with

other attributes from the Multiple Listing Service. The predicted value for Bird finds that the

addition of another desirable, less ubiquitous bird species improves mean home price by

$32,028, likely due to the human created landscapes on private properties immediately

surrounding a home sale. Curiously, the presence of a nearby park neither explained variation in

the ecological indicator nor contributed to home price elevation. This deliberately simple and

inexpensive indicator helped to direct attention to the composition of local landscapes in specific

areas to assess joint ecological and economic gains rather than presume a priori that open

greenspace jointly satisfies these dual objectives.

Ernstson, H. (2013). "The social production of ecosystem services: A framework for

studying environmental justice and ecological complexity in urbanized landscapes."

Landscape and Urban Planning 109(1): 7-17.

A framework is constructed for how to relate ecosystem services to environmental

justice. The benefits humans and society can derive from biophysical processes cannot be viewed

as objectively existing “out there”, but as entangled in social and political processes. This is

unpacked through the analytical moments of generation, distribution and articulation of

ecosystem services. Social practice moderates the generation of benefits from biophysical

processes (through urban development patterns and day-to-day management of urban

ecosystems), but also who in society that benefits from them, i.e. the distribution of ecosystem

services (viewed here as the temporal and spatial scales at which it is possible for humans to

benefit from biophysical processes). Moreover, for biophysical processes to attain value in

decision-making, a social practice of value articulation is needed. The framework then moves

between two levels of analysis. At the city-wide level, an ecological network translates how

urban ‘green’ areas, viewed as nodes, are interconnected by ecological flows (water, species

movement, etc.) where nodes have different protective and management capacities. The network

captures spatial complexity—what happens in one location, can have effects elsewhere. At the

local level, urban struggles over land-use are studied to trace how actors utilize artifacts and

social arenas to articulate how certain biophysical processes are of value. Competing networks of

value articulation strive to influence land-use, and multiple local studies bring understanding of

how power operates locally, informing city-wide analyses. Empirical studies from Stockholm,

Cape Town and other cities inform the framework.

Ellis, J. B. (2013). "Sustainable surface water management and green infrastructure in UK

urban catchment planning." Journal of Environmental Planning and Management 56(1):

24-41.

Based on the analysis of impervious surface cover and water balance studies, it is argued

that conventional, separately-sewered first-generation and alternative second-generation

sustainable drainage systems (SUDS) cannot provide a fully sustainable surface water

management approach for urban catchment planning. An extended approach based on the

introduction of micro-and meso-vegetative SUDS systems into a wider green infrastructure (GI)

framework is advocated to effectively address on-site and catchment urban surface water issues.

The approach is based on the integrated planning implementation of street ?greening?, with

optimisation of existing biofiltration SUDS solutions, together with green roofs, downspout

disconnection and sub-catchment riparian corridors to achieve a minimum 25?30% canopy cover

level. A leaf-out inventory procedure using GIS and satellite imagery can be employed to assess

potential vegetative SUDS locations and types, and their likely impact upon the urban water

cycle and receiving water health. However, there is a need to ensure that GI elements are

incorporated into planning approaches and protocols for urban drainage infrastructure provision.

De Kluizenaar, Y., et al. (2013). "Road traffic noise, air pollution components and

cardiovascular events." Noise and Health 15(67): 388.

Traffic noise and air pollution have been associated with cardiovascular health effects.

Until date, only a limited amount of prospective epidemiological studies is available on long-

term effects of road traffic noise and combustion related air pollution. This study investigates the

relationship between road traffic noise and air pollution and hospital admissions for ischemic

heart disease (IHD: International Classification of Diseases (ICD9) 410-414) or cerebrovascular

disease (cerebrovascular event [CVE]: ICD9 430-438). We linked baseline questionnaire data to

13 years of follow-up on hospital admissions and road traffic noise and air pollution exposure,

for a large random sample (N = 18,213) of inhabitants of the Eindhoven region, Netherlands.

Subjects with cardiovascular event during follow-up on average had higher road traffic noise

day, evening, night level (L den) and air pollution exposure at the home. After adjustment for

confounders (age, sex, body mass index, smoking, education, exercise, marital status, alcohol

use, work situation, financial difficulties), increased exposure did not exert a significant

increased risk of hospital admission for IHD or cerebrovascular disease. Relative risks (RRs) for

a 5 th to 95 th percentile interval increase were 1.03 (0.88-1.20) for L den; 1.04 (0.90-1.21) for

particulate matter (PM 10); 1.05 (0.91-1.20) for elemental carbon (EC); and 1.12 (096-1.32) for

nitrogen dioxide (NO 2 ) in the full model. While the risk estimate seemed highest for NO 2 , for

a 5 th to 95 th percentile interval increase, expressed as RRs per 1 μg/m 3 increases, hazard ratios

seemed highest for EC (RR 1.04 [0.92-1.18]). In the subgroup of study participants with a

history of cardiovascular disease, RR estimates seemed highest for noise exposure (1.19 [0.87-

1.64] for L den); in the subgroup of elderly RR seemed highest for air pollution exposure (RR

1.24 [0.93-1.66] for NO2).

Clowney, D. (2013). "Biophilia as an Environmental Virtue." Journal of Agricultural &

Environmental Ethics 26(5): 999-1014.

Beginning with E. O. Wilson’s notion of biophilia, our “innate tendency to focus on life

and life-like processes,” I construct an environmental virtue with the same name that meets

certain criteria an environmental virtue should meet. I argue that this virtue can have its status as

a virtue by its contribution to human flourishing, while having care for live nature as its target,

and care about live nature as its affective content. I explore its characteristics as both an

individual and a collective virtue, and finally show how cultivation of it might serve to unite

various communities in the cause of preserving biodiversity.

Calfapietra, C., et al. (2013). "Role of Biogenic Volatile Organic Compounds (BVOC)

emitted by urban trees on ozone concentration in cities: A review." Environ Pollut 183.

Biogenic Volatile Organic Compounds (BVOC) play a critical role in

biosphere/atmosphere interactions and are key factors of the physical and chemical properties of

the atmosphere and climate. However, few studies have been carried out at urban level to

investigate the interactions between BVOC emissions and ozone (O3) concentration. The

contribution of urban vegetation to the load of BVOCs in the air and the interactions between

biogenic emissions and urban pollution, including the likely formation of O3, needs to be

investigated, but also the effects of O3 on the biochemical reactions and physiological conditions

leading to BVOC emissions are largely unknown. The effect of BVOC emission on the O3

uptake by the trees is further complicating the interactions BVOCeO3, thus making challenging

the estimation of the calculation of BVOC effect on O3 concentration at urban level.

Berry, R., et al. (2013). "Tree canopy shade impacts on solar irradiance received by

building walls and their surface temperature." Building and Environment 69: 91-100.

Shading coefficients are used to predict the seasonal and diurnal benefit of architectural

shading devices. It is more difficult to model the impact of tree shade on building thermal

performance, and data is rare and varies greatly with species and season. We established a range

of tree shade amounts and shade qualities from which to develop simple, robust models that

predict external wall surface temperatures. We measured percentage shade cover, solar

irradiance and external surface temperature on north and west sun-bearing walls of three

identical buildings in spring and summer 2010/11. One building was shaded by tall Angophora

trees, another by smaller Fraxinus trees and one was unshaded. Tree shade reduced wall surface

temperatures by up to 9C and external air temperatures by up to 1??C. The smaller trees did little

to reduce external wall surface temperatures, and moving the tall trees further away from the

building wall eliminated their cooling benefits. Wall surface temperatures were best predicted by

shade cover and solar irradiance, and was most poorly predicted by shading coefficients, that

varied greatly through the day and the season, as tree height and leaf area index increased. Trees

can reduce external solar irradiance loads when they are close enough and tall enough to shade

the majority of the wall. To simulate the thermal performance benefits that trees provide, it is

necessary to account for seasonal, growth and phenological changes in tree shade amount and

quality.

Berry, R., et al. (2013). "Tree canopy shade impacts on solar irradiance received by

building walls and their surface temperature." Building and Environment 69: 91-100.

Shading coefficients are used to predict the seasonal and diurnal benefit of architectural

shading devices. It is more difficult to model the impact of tree shade on building thermal

performance, and data is rare and varies greatly with species and season. We established a range

of tree shade amounts and shade qualities from which to develop simple, robust models that

predict external wall surface temperatures. We measured percentage shade cover, solar

irradiance and external surface temperature on north and west sun-bearing walls of three

identical buildings in spring and summer 2010/11. One building was shaded by tall Angophora

trees, another by smaller Fraxinus trees and one was unshaded.

Tree shade reduced wall surface temperatures by up to 9 C and external air temperatures

by up to 1 C. The smaller trees did little to reduce external wall surface temperatures, and

moving the tall trees further away from the building wall eliminated their cooling benefits. Wall

surface temperatures were best predicted by shade cover and solar irradiance, and was most

poorly predicted by shading co- efficients, that varied greatly through the day and the season, as

tree height and leaf area index increased.

Trees can reduce external solar irradiance loads when they are close enough and tall

enough to shade the majority of the wall. To simulate the thermal performance benefits that trees

provide, it is necessary to account for seasonal, growth and phenological changes in tree shade

amount and quality.

Amorim, J. H., et al. (2013). "CFD modelling of the aerodynamic effect of trees on urban

air pollution dispersion." Science of The Total Environment 461–462: 541-551.

The current work evaluates the impact of urban trees over the dispersion of carbon

monoxide (CO) emitted by road traffic, due to the induced modification of the wind flow

characteristics. With this purpose, the standard flow equations with a kε closure for turbulence

were extended with the capability to account for the aerodynamic effect of trees over the wind

field. Two CFD models were used for testing this numerical approach. Air quality simulations

were conducted for two periods of 31 h in selected areas of Lisbon and Aveiro, in Portugal, for

distinct relative wind directions: approximately 45° and nearly parallel to the main avenue,

respectively. The statistical evaluation of modelling performance and uncertainty revealed a

significant improvement of results with trees, as shown by the reduction of the NMSE from 0.14

to 0.10 in Lisbon, and from 0.14 to 0.04 in Aveiro, which is independent from the CFD model

applied. The consideration of the plant canopy allowed to fulfil the data quality objectives for

ambient air quality modelling established by the Directive 2008/50/EC, with an important

decrease of the maximum deviation between site measurements and CFD results. In the non-

aligned wind situation an average 12% increase of the CO concentrations in the domain was

observed as a response to the aerodynamic action of trees over the vertical exchange rates of

polluted air with the above roof-level atmosphere; while for the aligned configuration an average

16% decrease was registered due to the enhanced ventilation of the street canyon. These results

show that urban air quality can be optimised based on knowledge-based planning of green

spaces.

Ziemann, P. J. and R. Atkinson (2012). "Kinetics, products, and mechanisms of secondary

organic aerosol formation." Chem Soc Rev 41.

Secondary organic aerosol (SOA) is formed in the atmosphere when volatile organic

compounds (VOCs) emitted from anthropogenic and biogenic sources are oxidized by reactions

with OH radicals, O3, NO3 radicals, or Cl atoms to form less volatile products that subsequently

partition into aerosol particles. Once in particles, these organic compounds can undergo

heterogenous/multiphase reactions to form more highly oxidized or oligomeric products. SOA

comprises a large fraction of atmospheric aerosol mass and can have significant effects on

atmospheric chemistry, visibility, human health, and climate. Previous articles have reviewed the

kinetics, products, and mechanisms of atmospheric VOC reactions and the general chemistry and

physics involved in SOA formation. In this article we present a detailed review of VOC and

heterogeneous/multiphase chemistry as they apply to SOA formation, with a focus on the effects

of VOC molecular structure on the kinetics of initial reactions with the major atmospheric

oxidants, the subsequent reactions of alkyl, alkyl peroxy, and alkoxy radical intermediates, and

the composition of the resulting products. Structural features of reactants and products discussed

include compound carbon number; linear, branched, and cyclic configurations; the presence of

C[double bond, length as m-dash]C bonds and aromatic rings; and functional groups such as

carbonyl, hydroxyl, ester, hydroxperoxy, carboxyl, peroxycarboxyl, nitrate, and peroxynitrate.

The intention of this review is to provide atmospheric chemists with sufficient information to

understand the dominant pathways by which the major classes of atmospheric VOCs react to

form SOA products, and the further reactions of these products in particles. This will allow

reasonable predictions to be made, based on molecular structure, about the kinetics, products,

and mechanisms of VOC and heterogeneous/multiphase reactions, including the effects of

important variables such as VOC, oxidant, and NOx concentrations as well as temperature,

humidity, and particle acidity. Such knowledge should be useful for interpreting the results of

laboratory and field studies and for developing atmospheric chemistry models. A number of

recommendations for future research are also presented.

Wania, A., et al. (2012). "Analysing the influence of different street vegetation on traffic-

induced particle dispersion using microscale simulations." J Environ Manage 94.

Urban vegetation can be viewed as compensation to the environmental drawbacks of

urbanisation. However, its ecosystem function is not well-known and, for urban planning,

vegetation is mainly considered as an element of urban design. This article argues that planning

practice needs to re-examine the impact of vegetation cover in the urban fabric given our

evaluation of vegetation’s effects on air quality, including the dispersion of traffic-induced

particles at street level. Using the three-dimensional microclimate model ENVI-met®, we

evaluate these effects regarding the height-to-width ratio of streets flanked by buildings and the

vertical and horizontal density of street vegetation. Our results reveal vegetation’s effect on

particle dispersion through its influence on street ventilation. In general, vegetation was found to

reduce wind speed, causing inhibition of canyon ventilation and, consequently, an increase in

particle concentrations. Vegetation was also found to reduce wind speed at crown-height and to

disrupt the flow field in close vicinity to the canopy. With increasing height-to-width ratio of

street canyons, wind speed reduction increases and the disturbance of the flow impacts across a

canyon’s entire width. We also found that the effect is more pronounced in configurations with

poor ventilation, such as the low wind speed, perpendicular inflow direction, and in deep

canyons cases.

Strohbach, M. W., et al. (2012). "Erratum to “The carbon footprint of urban green space—

A life cycle approach” [Landsc. Urban Plann. 104 (2012) 220–229]." Landscape and Urban

Planning 105(4): 445.

Cities play an important role in the global carbon cycle. They produce a large proportion

of CO2 emissions, but they also sequester and store carbon in urban forests and green space.

However, sequestration by urban green space is difficult to quantify and also involves emissions.

The carbon footprint analysis is an established method for systematically quantifying carbon

sinks and sources throughout the lifetime of goods and services. We applied this method to an

urban green space project in Leipzig, Germany. To the best of our knowledge it is the first

application in this field. We simulated carbon sequestration by growing trees and contrasted it

with all related carbon sources, from construction and maintenance over the lifetime of 50 years.

In addition, we explored alternative design and maintenance scenarios. Total net sequestration

was predicted to be between 137 and 162 MgCO2 ha−1 . Park-like design and maintenance is

less effective than forest-like design and maintenance. Much uncertainty is linked to tree growth

and tree mortality. Increasing annual tree mortality from 0.5 to 4% reduces sequestration by over

70%. In conclusion, urban green space can act as a carbon sink and the design and maintenance

have a strong influence on the carbon footprint. The carbon footprint analysis is a valuable tool

for estimating the long- term environmental performance of urban green space projects.

Compared to emissions from people, the overall potential for carbon mitigation is limited, even

in cities such as Leipzig with widely available space for new urban green space.

Strohbach, M. W., et al. (2012). "The carbon footprint of urban green space—A life cycle

approach." Landscape and Urban Planning 104(2): 220-229.

Cities play an important role in the global carbon cycle. They produce a large proportion

of CO2 emissions, but they also sequester and store carbon in urban forests and green space.

However, sequestration by urban green space is difficult to quantify and also involves emissions.

The carbon footprint analysis is an established method for systematically quantifying carbon

sinks and sources throughout the lifetime of goods and services. We applied this method to an

urban green space project in Leipzig, Germany. To the best of our knowledge it is the first

application in this field. We simulated carbon sequestration by growing trees and contrasted it

with all related carbon sources, from construction and maintenance over the lifetime of 50 years.

In addition, we explored alternative design and maintenance scenarios. Total net sequestration

was predicted to be between 137 and 162&#xa0;MgCO2&#xa0;ha−1. Park-like design and

maintenance is less effective than forest-like design and maintenance. Much uncertainty is linked

to tree growth and tree mortality. Increasing annual tree mortality from 0.5 to 4% reduces

sequestration by over 70%. In conclusion, urban green space can act as a carbon sink and the

design and maintenance have a strong influence on the carbon footprint. The carbon footprint

analysis is a valuable tool for estimating the long-term environmental performance of urban

green space projects. Compared to emissions from people, the overall potential for carbon

mitigation is limited, even in cities such as Leipzig with widely available space for new urban

green space.

Pugh, T. A. M., et al. (2012). "Effectiveness of green infrastructure for improvement of air

quality in urban street canyons." Environ Sci Technol 46.

Street-level concentrations of nitrogen dioxide (NO2) and particulate matter (PM) exceed

public health standards in many cities, causing increased mortality and morbidity.

Concentrations can be reduced by controlling emissions, increasing dispersion, or increasing

deposition rates, but little attention has been paid to the latter as a pollution control method. Both

NO2 and PM are deposited onto surfaces at rates that vary according to the nature of the surface;

deposition rates to vegetation are much higher than those to hard, built surfaces. Previously, city-

scale studies have suggested that deposition to vegetation can make a very modest improvement

(<5%) to urban air quality. However, few studies take full account of the interplay between

urban form and vegetation, specifically the enhanced residence time of air in street canyons. This

study shows that increasing deposition by the planting of vegetation in street canyons can reduce

street-level concentrations in those canyons by as much as 40% for NO2 and 60% for PM.

Substantial street-level air quality improvements can be gained through action at the scale of a

single street canyon or across city-sized areas of canyons. Moreover, vegetation will continue to

offer benefits in the reduction of pollution even if the traffic source is removed from city centers.

Thus, judicious use of vegetation can create an efficient urban pollutant filter, yielding rapid and

sustained improvements in street-level air quality in dense urban areas.

Pham, T. T. H., et al. (2012). "Spatial distribution of vegetation in Montreal: an uneven

distribution or environmental inequity?" Landscape Urban Plann 107.

Growing evidence is showing that across North American cities, underprivileged

populations and racial and/or visible groups have disproportionally less access to vegetation than

affluent groups, raising concerns of environmental inequity. This study aims to verify whether in

Montreal (Canada) there is environmental inequity resulting from variations in urban vegetation

for low-income people and visible minorities. More specifically, various vegetation indicators

were extracted from very-high-resolution satellite images, including the proportion of city

blocks, streets, alleys and backyards covered by total vegetation and trees/shrubs. Socio-

demographic variables were obtained from 2006 Canada Census and rescaled to the city block

level, by using a population-based weighing method. Statistical analysis indicates that there are

disparities in the distribution of vegetation in Montreal which disfavour low-income people and,

to a lesser extent, visible minorities. Disparities are also more pronounced on public land (streets,

alleys) than on private land (backyards). Income is a major factor but cannot fully explain

inequities among visible minorities. Notwithstanding the weak extent of such disparities, those

vulnerable communities might need a better access to ecological services provided by vegetation,

notably such as heat island mitigation. Compensatory equity needs to be addressed and our

findings call for authorities to reconsider greening budgetary allocation and practices, especially

in the most deprived neighbourhoods of the city.

Islam, M. N., et al. (2012). "Pollution attenuation by roadside greenbelt in and around

urban areas." Urban Forestry & Urban Greening 11(4): 460-464.

Greenbelts are effective tools for mitigation of traffic induced air and noise pollution. In

this study, the potential role of greenbelts along the roadside for the reduction of air pollution

and noise levels has been assessed by using seasonally monitored data in a megacity of

Bangladesh. Correlation analysis was performed between the vegetation status, measured by

canopy density and shelterbelt porosity, and the total suspended particles (TSP) removal

percentage. Further, the reduction of noise level was also analyzed. The results showed that the

greenbelts greatly contributed to reduce TSP pollution and it was as much as 65%. Noise level

reduction was also achieved up to 17 dB when compared to the open area. Moreover, TSP

removal percentage was correlated to the crown density. Area having higher crown density

demonstrated less air pollution and lower level of noise compared to the area having lower

crown density. Greenbelt showed better performance in summer time than winter.

Hagler, G. S. W., et al. (2012). "Field investigation of roadside vegetative and structural

barrier impact on near-road ultrafine particle concentrations under a variety of wind

conditions." Sci Total Environ 419.

Roadside barriers, such as tree stands or noise barriers, are prevalent in many populated

areas and have been shown to affect the dispersion of traffic emissions. If roadside noise barriers

or tree stands are found to consis- tently lower ground-level air pollution concentrations in the

near-road environment, this may be a practical strategy for reducing exposures to air

contaminants along populated traffic corridors. This study measured ultra- fine particle (UFP)

concentrations using an instrumented mobile measurement approach, collecting data on major

roadways and in near-road locations for more than forty sampling sessions at three locations in

central North Carolina, USA. Two of the sampling sites had relatively thin tree stands, one

evergreen and one deciduous, along a portion of the roadway. The third sampling site had a brick

noise wall along a portion of the road. At 10 m from the road, UFPs measured using a mobile

sampling platform were lower by approximately 50% behind the brick noise wall relative to a

nearby location without a barrier for multiple meteorological conditions. The UFP trends at the

vegetative barrier sites were variable and the barrier effect is uncertain. In some cases, higher

con- centrations were observed behind the vegetative barrier, with respect to the clearing, which

may be due to gaps in the thin tree stands allowing the transport of traffic-related air pollution to

near-road areas behind the vege- tation. On-road sampling revealed no consistent difference in

UFP levels in on-road portions of the road with or without a roadside barrier present. These

findings support the notion that solid roadside barriers may mitigate near-road impact. Given the

co-benefits of vegetative barriers in the urban landscape, research regarding the mitigation

potential of vegetative barriers of other configurations (e.g., greater density, wider buffer) is

encouraged.

Dirks, K. N., et al. (2012). "Personal exposure to air pollution for various modes of

transport in Auckland, New Zealand." Open Atmos Sci J 6.

This paper investigates the carbon monoxide (CO) doses received while commuting by

different modes (car, bus, train, motorcycle, bicycle and running), taking into account the

commute time as well as the level of physical activity required. While the participants were

constrained to travel at specific peak traffic times and between designated start and end points,

they were free to choose a route appropriate for their mode of transport.

The results of this study suggest that the lowest exposures (concentrations of pollutants) are

experienced by train commuters, largely a reflection of the routes being removed from any

significant road traffic. Motorcyclists experienced significantly higher average concentrations as

a result of high-concentration and very-short-duration peaks not seen in the traces of car and bus

commuters travelling on the same road. Travel by bus along a dedicated busway was also found

to be effective in reducing commuter air pollution exposure compared to travel by car on a

congested stretch of motorway.

The average concentrations to which cyclists and runners were exposed were found to be

not significantly different for those travelling by car or bus (except when on dedicated

pedestrian/cycleways). However, when the increased physical activity that is required is taken

into account (leading to higher volumes of air breathed) along with the increased commuting

time (especially in the case of runners), the air pollution doses (as estimated by the product of the

concentration, commute time and breathing factor) were found to be significantly higher than for

the motorised modes. The results suggest that separate pedestrian/cycleways go some way

towards providing healthier options for cyclists and pedestrians.

Center, N. E. E. F. (2012). "Green Infrastructure Resource Directory."

Green infrastructure is an approach for managing stormwater that uses vegetation and

soils to capture and treat rainwater where it falls. Unlike single-purpose gray infrastructure,

green infrastructure realizes multiple benefits at once, including flood mitigation, improved

water and air quality, community beautification, provision of recreational opportunities, and

energy and cost savings. This resource directory is intended to help communities design,

implement, fund, and monitor green infrastructure practices and programs. It was compiled by

the Environmental Finance Center Network through the Capacity Building for Sustainable

Communities program funded by U.S. Department of Housing and Urban Development and U.S.

Environmental Protection Agency. Through this program, EFCN is providing capacity building

and technical assistance to recipients of grants from the federal Partnership for Sustainable

Communities.

Cameron, R. W. F., et al. (2012). "The domestic garden – Its contribution to urban green

infrastructure." Urban Forestry & Urban Greening 11(2): 129-137.

Domestic gardens provide a significant component of urban green infrastructure but their

relative contribution to eco-system service provision remains largely un-quantified. ‘Green

infrastructure’ itself is often ill-defined, posing problems for planners to ascertain what types of

green infrastructure provide greatest benefit and under what circumstances. Within this context

the relative merits of gardens are unclear; however, at a time of greater urbanization where

private gardens are increasingly seen as a ‘luxury’, it is important to define their role precisely.

Hence, the nature of this review is to interpret existing information pertaining to

gardens/gardening per se, identify where they may have a unique role to play and to highlight

where further research is warranted. The review suggests that there are significant differences in

both form and management of domestic gardens which radically influence the benefits.

Nevertheless, gardens can play a strong role in improving the environmental impact of the

domestic curtilage, e.g. by insulating houses against temperature extremes they can reduce

domestic energy use. Gardens also improve localized air cooling, help mitigate flooding and

provide a haven for wildlife. Less favourable aspects include contributions of gardens and

gardening to greenhouse gas emissions, misuse of fertilizers and pesticides, and introduction of

alien plant species. Due to the close proximity to the home and hence accessibility for many,

possibly the greatest benefit of the domestic garden is on human health and well-being, but

further work is required to define this clearly within the wider context of green infrastructure.

Wang, Z. and J. S. Zhang (2011). "Characterization and performance evaluation of a full-

scale activated carbon-based dynamic botanical air filtration system for improving indoor

air quality." Building and Environment 46(3): 758-768.

A dynamic botanical air filtration system (DBAF) was developed for evaluating the short

and long-term performance of botanical air cleaning technology under realistic indoor

conditions. It was a fan-assisted with controlled airflow, activated-carbon/hydroculture based

potted plant unit. The DBAF was first tested using a full-scale stainless chamber to evaluate its

short-term performance. It was then integrated in the HVAC system of a new office space (96.8

m2) to study the effects of moisture content in the root bed on the removal efficiency, and the

long-term performance. The results indicated that 5% outdoor air plus botanical filtration lead to

the similar indoor formaldehyde/toluene concentration level as 25% outdoor air without

filtration, which means that the filtration system was equivalent to 20% outdoor air (476 m3/h).

The DBAF was effective for removing both formaldehyde and toluene under 5–32% volumetric

water content of the root bed. It also performed consistently well over the relatively long testing

period of 300 days while running continuously. The reduction in outdoor ventilation rate while

using the botanical filtration system to maintain acceptable air quality would lead to 10–15%

energy saving for the cold climate (Syracuse, NY), based on simulation analysis using

EnergyPlus. For winter condition, the filter was also found to increase the supply air RH by 20%,

which would decrease the dryness of air. For summer condition, the increase of RH in summer

would be within 15% of the RH condition when no botanical air filtration is present.

Tallis, M., et al. (2011). "Freer-Smith: Estimating the removal of atmospheric particulate

pollution by the urban tree canopy of London, under current and future environments."

Landscape Urban Plann 103.

Urban green space and particularly the tree canopy have been highlighted as offering a

mitigation potential against atmospheric particulate pollution. In this paper current and future

particulate (PM10) deposition to the urban tree canopy of the Greater London Authority (GLA)

was estimated. A modelling approach was used based on the Urban Forest Effects Model

(UFORE) and a modified version. Here we give evidence showing that these deposition models

can be adapted to run from annual mean meteorological and PM10 concentration data, thus

providing a methodology to examine future scenarios.

Depending on the modelling approach, the urban canopy of the GLA is currently

estimated to remove between 852 and 2121 tonnes of PM10 annually; representing between

0.7% and 1.4% of PM10 from the urban boundary layer. Estimates of PM10 removal which take

into account a planned increased in tree cover, from the current 20% to 30% of the GLA land

area, suggest deposition of 1109–2379 tonnes (1.1–2.6% removal) by the year 2050. The

evidence provided here suggests that the targeting of tree planting in the most polluted areas of

the GLA and particularly the use of street trees which have the greatest exposure to PM10,

would have the greatest benefit to future air quality. The increased deposition would be greatest

if a larger proportion of coniferous to broadleaved trees were used at such sites.

Smith, C. L., et al. (2011). "Fine-scale spatial temperature patterns across a UK

conurbation." Clim Change 109.

The public health implications of a warming urban environment mean that appropriate

action by planners, designers and health workers will be necessary to minimise risk under future

climate scenarios. Data at an appropriate spatial scale are required by user groups in order to

identify key areas of vulnerability. Thermal mapping of a UK urban conurbation was carried out

during the summers of 2007 and 2008 with the aim of providing high spatial resolution

temperature data. The air temperature results showed an average daytime (night time) urban–

rural thermal contrast of 3◦C (5◦C) on summer days (nights) with ideal urban heat island (UHI)

conditions. The intensity of the daytime surface temperature heat island was found to exceed

10◦C. The measured data were used to derive an empirical model of spatial temperature patterns

based upon characteristics of land use, distance from urban centre and building geometry. This

model can be used to provide sub-kilometre resolution temperature data which are required by

decision makers and can provide a mechanism for downscaling climate model output.

Mitchell, R., et al. (2011). "A comparison of green space measures for epidemiological

research." J Epidemiol Community Health 65.

Background The potential for natural environments to be salutogenic has received

growing interest from epidemiologists, but there has been no critical examination of the extent to

which associations between green space and health might vary according to the indicator of

green space coverage used.

Methods Three different indicators of green space coverage were derived for a set of 268

small areas in four cities within Britain. The indicators had different origins and provided a

spectrum of sensitivity from larger spaces only, through to ambient greenery. Two indicators

reproducible for anywhere in Europe were included. Agreement between the indicators on the

quantity of green space in a small area, and their independent association with measures of

mortality and self-reported morbidity, were compared.

Results Overall, the indicators showed relatively close overall agreement (all r2>0.89,

p<0.001). However, agreement varied by level of area socioeconomic deprivation (p<0.001).

The indicator that detected larger spaces only found less green space in areas of socioeconomic

deprivation than the other two. Despite this difference, all indicators showed similar protective

associations with the risk of mortality and self-reported morbidity suggesting that larger green

spaces may be more important for health effects than smaller spaces.

Conclusions Associations between green space indicator and health were not sensitive to

indicator origin and type. This raises the possibility of trans-European epidemiological studies.

Larger green spaces may be the most important for health effects, but may also be less prevalent

in more deprived areas.

Leung, D. Y. C., et al. (2011). "Effects of urban vegetation on urban air quality."

Landscape Res 36.

Vegetation has been well recognized for its ability in improving air quality and

alleviating global warming. Tree planting has been used to mitigate urban heat island

phenomena, sequester carbon dioxide, and help to trap air pollutants on leaves. Because some

plant species emit biogenic volatile organic compounds (BVOCs), planting of some cultivars

increase ozone and particulate matter ambient concentration and hence deteriorate air quality.

Moreover, pollen grains and fungal spores from plants are health hazards for allergic or other

sensitive members of the population. This paper reviews benefits and limited hazards of urban

vegetation on air quality, highlighting useful computer simulations for predicting some of the

interaction between urban forestry and the ambient atmosphere. To maximize the beneficial

environmental effects of urban forestry, careful design, planning, and cost–benefit analysis

would be required.

Kays, S. J. (2011). "Phytoremediation of indoor air–Current state of the art." The Value

Creation of Plants for Future Urban Agriculture: 3-21.

Phytoremediation of indoor air utilizes plants to remove or neutralize environmental

contaminants such as volatile organic compounds (VOCs) in the air of homes, offices and other

enclosed buildings. Certain plant species, working in tandem with yet unidentified

microorganisms in the root zone, have the ability to remove VOCs and purify the air.

Hundreds of VOCs have been identified as indoor contaminants (ACGIH, 1995; EPA, 1989;

Won et al., 2005). For example, the U.S. Environmental Protection Agency (EPA) reported

detection of more than 900 VOCs in the air of public buildings (EPA, 1989). In a Finnish study,

over 200 VOCs were identified in each of 26 homes (Kostiainen, 1995). An example of the types

of volatiles that might be encountered is presented in Table 1 which lists the VOCs found in two

houses surveyed in Athens, Georgia that had serious air quality problems. The volatiles in the

first house were emanating from toxic drywall and in the second from insulation that had been

blown into the air space within the outside walls. Indoor air in cities has been reported to be as

much as 5 to 1000 times more polluted than exterior air (Brown et al., 1994; Godish, 1995;

Kostianen, 1995; Brown, 1997; Ingrosso, 2002; Yang et al., 2004; Zabiegała, 2006). The

chemicals are absorbed into human and animal bodies through inhalation and in some instances,

through direct penetration of the skin (McDougal et al., 1990).

While the initial work on phytoremediation of indoor air was done in the 1970s, it has not

been until recently that interest in the subject has spread. Currently, the leading research

programs are in South Korea. To date, a significant portion of the research has been directed

toward identifying superior phytoremediation species of indoor plants. While the results have

been very positive, the lack of adequate funding has impeded exploring the basic mechanisms

operative and making the transition from the laboratory to real world homes and offices. As a

consequence, what we currently know is vastly exceeded by what we do not, a situation that is

evident from, for example, the very limited number of VOCs that have been tested.

The public has displayed tremendous interest in the potential of phytoremediation and

there is a growing awareness of the serious health issues arising from breathing polluted indoor

air. Four popular books on the subject are currently available (Son, 2004; Son, 2009; Wolverton,

1996; Wolverton and Takenaka, 2010).

Joye, Y. and A. van den Berg (2011). "Is love for green in our genes? A critical analysis of

evolutionary assumptions in restorative environments research." Urban Forestry & Urban

Greening 10(4): 261-268.

Within the field of restorative environments research, it is commonly assumed that

restorative responses, triggered by exposure to natural elements and settings, are ultimately

adaptive traits originating from our species’ long evolutionary history in natural environments.

The aim of this article is to critically investigate the viability of this evolutionary view on

restoration. In doing so, we specifically focus on Stress Recovery Theory (SRT), as this

theoretical framework has most extensively elaborated on the supposed evolutionary origins of

restoration. A detailed analysis of SRT’s psycho- evolutionary framework shows that neither

current empirical evidence nor conceptual arguments provide any strong support for the

hypothesis of restorative responses to nature as an ancient evolved adaptive trait. Based on this

conclusion we put forward an alternative model for restorative responses to nature based on

processing fluency, which prima facie circumvents some of the pitfalls associated with

evolutionary accounts for restoration. The Discussion section reflects on the implications of our

critical discussion for the theory and practice of urban forestry and urban greening.

Buccolieri, R., et al. (2011). "Analysis of local scale tree-atmosphere interaction on

pollutant concentration in idealized street canyons and application to a real urban

junction." Atmos Environ 45.

This paper first discusses the aerodynamic effects of trees on local scale flow and

pollutant concentration in idealized street canyon configurations by means of laboratory

experiments and Computational Fluid Dynamics (CFD). These analyses are then used as a

reference modelling study for the extension a the neighbourhood scale by investigating a real

urban junction of a medium size city in southern Italy.

A comparison with previous investigations shows that street-level concentrations

crucially depend on the wind direction and street canyon aspect ratio W/H (with W and H the

width and the height of buildings, respectively) rather than on tree crown porosity and stand

density. It is usually assumed in the literature that larger concentrations are associated with

perpendicular approaching wind. In this study, we demonstrate that while for tree-free street

canyons under inclined wind directions the larger the aspect ratio the lower the street-level

concentration, in presence of trees the expected reduction of street-level concentration with

aspect ratio is less pronounced.

Observations made for the idealized street canyons are re-interpreted in real case scenario

focusing on the neighbourhood scale in proximity of a complex urban junction formed by street

canyons of similar aspect ratios as those investigated in the laboratory. The aim is to show the

combined influence of building morphology and vegetation on flow and dispersion and to assess

the effect of vegetation on local concentration levels. To this aim, CFD simulations for two

typical winter/spring days show that trees contribute to alter the local flow and act to trap

pollutants. This preliminary study indicates that failing to account for the presence of vegetation,

as typically practiced in most operational dispersion models, would result in non-negligible

errors in the predictions.

Research Highlights: ► Trees influence pollutant concentration distribution in urban street

canyons. ► Failing to account for the presence of trees may result in critical errors in model

predictions. ► Building morphology and vegetation have to be analysed together. ► Analyses of

data from various sources (CFD modelling, wind tunnel and monitoring stations) are necessary

to produce a comprehensive picture of complex flow and dispersion phenomena within urban

areas.

Beruto, M. (2011). Introduction of new ornamental plants and production technologies:

case studies. VII International Symposium on New Floricultural Crops 1000.

The floriculture is a dynamic sector where a wide range of products are considered. To

stand the global competitiveness it is mandatory to introduce novelties into the market. Moreover

a strong cooperation among the different links of the productive chain is a prerequisite for

shortening the time to valorise the new products. R&D is an important step to introduce product

and process innovation. The intended outcomes of this work are to present some case studies

carried out at Regional Institute for Floriculture (IRF), Sanremo, addressed to support the

productive world in enhancing niche crops for the export. New articles for the market have been

obtained through the development of new propagation schemes (Ranunculus asiaticus), the

achievement of innovative genotypes (Argyranthemum frutescens) and the exploitation of wild

sources (Euphorbia spinosa).

Aydogan, A. and L. D. Montoya (2011). "Formaldehyde removal by common indoor plant

species and various growing media." Atmospheric Environment 45(16): 2675-2682.

Three porous materials (growstone, expanded clay and activated carbon) were evaluated

as hydroponic growing media and for their individual ability to remove the indoor volatile

organic compound form- aldehyde under three conditions: growing medium alone, dry medium

in a pot, and wet medium in a pot. The total percent-reduction of formaldehyde by each growing

media was evaluated over a 10-h period. In all cases, activated carbon achieved the highest

removal under the three conditions studied with average percent reductions measured at about

98%. Four common interior plants: Hedera helix (English ivy), Chrysanthemum morifolium (pot

mum), Dieffenbachia compacta (dump cane) and Epi- premnum aureum (golden pathos) growing

in growstone were then tested for their ability to remove formaldehyde. The removal capacity of

the aerial plant parts (AP), the root zone (RZ) and the entire plant (EP) growing in growstone

were determined by exposing the relevant parts to gaseous formaldehyde (w2000 mg m 3) in a

closed chamber over a 24-h period. The removal efficiency between species and plant parts were

compared by determining the time interval required to decrease about 2/3 of the total

formaldehyde concentration reduction, T2/3. The T2/3 measured were 23, 30, 34 and 56 min for

EP of C. morifolium, E. aureum, D. compacta and H. helix, respectively. The formaldehyde

removal by the root zone was found to be more rapid than the removal by the aerial plant parts.

Shashua-Bar L, P. D., Erell E. (2010b). The influence of trees and grass on outdoor thermal

comfort in a hot-arid environment.

The effects of vegetation on human thermal stress in a hot-arid region were tested in two

semi-enclosed urban spaces with various combinations of mature trees, grass, overhead shading

mesh and paving. The index of thermal stress was calculated hourly from measured

meteorological data in the studied sites to evaluate thermal comfort in the different spaces based

on radiative and convective pedestrian–environment energy exchanges and sweat efficiency, and

expressed on a thermal sensation scale ranging from ‘comfortable’ to ‘very hot’. The efficiency

of water use in providing improved comfort was gauged for each of the vegetative landscaping

treatments by comparing the total evapotranspiration with the reduction in thermal stress, both

expressed in terms of their values in equivalent energy. While conditions in a paved, unshaded

courtyard were found to be uncomfortable throughout the daytime hours (with half of these hours

defined by severe discomfort), each of the landscape treatments made a clear contribution to

improved thermal comfort. With shading, either by trees or mesh, discomfort was reduced in

duration by over half and limited in maximum severity when the shading was placed above

paving. When combined with grass, both shading mechanisms yielded comfortable conditions at

all hours. In both cases, the effect of trees was more pronounced than that of the mesh, but by a

small margin. With unshaded grass, ‘hot’ conditions in the courtyard were restricted to a short

period in mid-afternoon, a considerable improvement over unshaded paving, attributable mainly

to the lower radiant surface temperatures.

Shashua-Bar L, P. O., Bitan A, Boltansky D, Yaakov Y. (2010a). Microclimate modelling of

street tree species effects within the varied urban morphology in the Mediterranean city of

Tel Aviv, Israel.

Microclimate formation and its significance in urban planning was examined through two

components that predominate in affecting the city’s climate: built-up morphology and urban

shade trees. The methodological approach focus is on a generalization procedure for quantifying

the thermal effect of any studied situation through parameterization of the vegetated variables

and the built-up forms. The analysis is integrative, using empirical climatic data followed by an

analytical study for generalization and sensitivity analysis using an integrative model, the Green

CTTC model.

Three urban tree species predominant in the Tel Aviv gardens and streets, with different

canopy characteristics, and three levels of building densities were analysed to determine their

thermal effect on an urban street microclimate. The variables were parameterized according to

six basic cooling attributes for the studied tree species in urban gardens in Tel Aviv, and

according to three geometric built-up parameters for the studied urban street.

The integrative modelling approach of considering all changes simultaneously was

illustrated on an urban boulevard in Tel Aviv. The analysis demonstrates the shortcomings of

piecemeal modelling and the merits of the integrative approach. The study indicates the

importance of urban trees in alleviating the heat island effect in a hot and humid summer. The

tree cooling effect was found to be strongly related to the built form geometry. In all the studied

cases, the thermal effect of the tree was found to depend mainly on its canopy coverage level and

planting density in the urban street and little on other species characteristics. The methodology of

analysis presented in this paper can be applied to develop an operational tool in assessing for an

urban open space the integrative thermal effects of different tree species, and of the varied urban

morphology and the interaction between them.

Thornes, J., et al. (2010). "Communicating the value of atmospheric services." Meteorol

Appl 17.

The atmosphere is one of the most valuable resources on the planet and yet because it is

largely invisible it tends to be taken for granted and is increasingly being exploited and

commodified. This paper presents 12 Atmospheric Services that are vital to human well-being

and the existence of the biosphere. The Total Economic Value of the atmosphere is estimated to

be at least between 100 and 1000 times the Gross World Product (GWP was approximately £43

Trillion in 2008). It is only by appreciating the value of the atmosphere to society that we can

understand how we need to communicate sustainable management of the atmosphere and treat it

as a global commons. It is also important to realize which Atmospheric Services are currently

under threat. Only by appreciating the full range of services provided by the atmosphere can the

real cost of geo-engineering the climate be calculated. Before geo-engineering of the climate can

ever be considered seriously a Law of the Atmosphere will be required.

Sellmer, J. C. (2010). "Bringing Nature Home: How Native Plants Sustain Wildlife in Our

Gardens." HortTechnology 20(1): 257-.

Bringing Nature Home is the first book that this reviewer has found on the market to

provide a discussion on how by using native plants in the home landscape, we can support the

native fauna in the garden, landscape, and surrounding community. The book consists of 14

chapters with the first seven chapters providing arguments against non-native plants. Chapters 8

through 10 begin the discussion of biodiversity and approaches for using natives in the

landscape. Chapters 11 through 13 provide insight into what native plants to use to attract native

insects that feed upon those plants. The final chapter provides answers to common tough

questions surrounding the debate about the use of native and non-native plants in the home

landscape. The appendices consist of three sections with the first listing native plants classified

by type (e.g., shade and specimen trees, shrub and understory trees, conifers, vines, grasses,

herbaceous perennials) with wildlife value for general regions across the country (e.g., Mid-

Atlantic, Southeast, Southwest, and Pacific Northwest). Appendix two is a table of butterflies

and moths and their hosts, and appendix three provides some unpublished data from the author's

research on insect herbivory on woody native and alien species in his backyard and published

work by his graduate student on early successional perennials.

Seaman, P. J., et al. (2010). "It’s not just about the park, it’s about integration too: why

people choose to use or not use urban greenspaces." Int J Behav Nutr Phys Act 7.

Background: Greenspace has the potential to be a vital resource for promoting healthy

living for people in urban areas, offering both opportunities for physical activity and wellbeing.

Much research has explored the objectively measurable factors within areas to the end of

explaining the role of greenspace access in continuing health inequalities. This paper explores

the subjective reasons why people in urban areas choose to use, or not use, local public

greenspace.

Methods: In-depth interviews with 24 people living in two areas of Glasgow, United

Kingdom were conducted, supplemented with participant photography and participatory

methods. Data was thematically categorised to explore subjectively experienced facilitators and

barriers to greenspace use in urban areas.

Results: From the perspective of current and potential urban greenspace users, access is

revealed to be about more than the physical characteristics of neighbourhoods, greenspace

resources or objectively measurable features of walkability and connectivity. Subjectively, the

idea of walkability includes perceptions of social cohesion at a community level and the level of

felt integration and inclusion by individuals in their communities. Individual's feelings of

integration and inclusion potentially mitigate the effects of experiential barriers to urban

greenspace access, such as evidence of anti-social behaviour.

Conclusions: We conclude that improving access to greenspace for all in urban

communities will require more than providing high quality resources such as parks, footpaths,

activities and lighting. Physical availability interacts with community contexts already

established and a holistic understanding of access is required. A key cultural component of areas

and neighbourhoods is the level of social cohesion, a factor that has the potential to reinforce

existing health inequalities through shaping differentiated greenspace access between subgroups

of the local population.

Rae RA, S. G., Braden J. (2010). Public reactions to new street tree planting.

MillionTrees NYC, which has the goal of planting one million trees in New York City by

2017, is intended to make New York City a greener, more sustainable city and is part of the

Mayor’s comprehensive long term strategic plan, PlaNYC. Through planting a tree at every

suitable sidewalk location in the city, the City of New York is transforming blocks and

communities, and providing a variety of environmental, social and aesthetic benefits. This article

examines the large scale municipal planting of new street trees and the reaction by some of the

pubic to this planting.

Trees offer benefits to the city overall, but the public may not understand these benefits

or the street tree planting process. Between 2007 and 2009, the Department of Parks &

Recreation planted 53,235 new street trees, and received 4,108 items of correspondence from the

public. The majority of this correspondence consisted of public comments about the City’s new

street tree planting policies and processes including placement objections, maintenance concerns,

reports of resultant damage from tree planting operations, requests for new street trees and

reports of tree conditions.

This study describes the operational policies that guide New York City's municipal street

tree planting, and results of content and spatial analysis of the correspondence. Qualitative

analysis of the correspondence revealed public perceptions and concerns related to the

MillionTreesNYC program. Spatial analysis explored the relationship between the planting

locations of new street trees and the locations of the citizen correspondence.

Public reactions to this large scale municipal planting are related to the dual public and private

nature of the sidewalk, issues of territoriality, responsibility, aesthetics and place attachment.

Correspondence volume was associated with the scale of the new street tree block planting

program, and the effectiveness of NYC’s 311 Customer Service Center. The discussion suggests

that increased public education on tree benefits and notification of planting processes could

change perceptions of new street tree planting. This study also identifies the potential for

targeted research studies to further investigate public reactions to new street tree planting.

Norgaard, R. B. (2010). "Ecosystem services: From eye-opening metaphor to complexity

blinder." Ecol Econ 69.

What started as a humble metaphor to help us think about our relation to nature has

become integral to how we are addressing the future of humanity and the course of biological

evolution. The metaphor of nature as a stock that provides a flow of services is insufficient for

the difficulties we are in or the task ahead. Indeed, combined with the mistaken presumption that

we can analyze a global problem within a partial equilibrium economic framework and reach a

new economy project-by-project without major institutional change, the simplicity of the stock-

flow framework blinds us to the complexity of the human predicament. The ecosystem services

approach can be a part of a larger solution, but its dominance in our characterization of our

situation and the solution is blinding us to the ecological, economic, and political complexities of

the challenges we actually face.

Lundholm, J., et al. (2010). "Plant Species and Functional Group Combinations Affect

Green Roof Ecosystem Functions." PLoS ONE 5(3).

Background: Green roofs perform ecosystem services such as summer roof temperature

reduction and stormwater capture that directly contribute to lower building energy use and

potential economic savings. These services are in turn related to ecosystem functions performed

by the vegetation layer such as radiation reflection and transpiration, but little work has

examined the role of plant species composition and diversity in improving these functions.

Methodology/Principal Findings: We used a replicated modular extensive (shallow

growing-medium) green roof system planted with monocultures or mixtures containing one,

three or five life-forms, to quantify two ecosystem services: summer roof cooling and water

capture. We also measured the related ecosystem properties/processes of albedo,

evapotranspiration, and the mean and temporal variability of aboveground biomass over four

months. Mixtures containing three or five life-form groups, simultaneously optimized several

green roof ecosystem functions, outperforming monocultures and single life-form groups, but

there was much variation in performance depending on which life-forms were present in the

three life-form mixtures. Some mixtures outperformed the best monocultures for water capture,

evapotranspiration, and an index combining both water capture and temperature reductions.

Combinations of tall forbs, grasses and succulents simultaneously optimized a range of

ecosystem performance measures, thus the main benefit of including all three groups was not to

maximize any single process but to perform a variety of functions well.

Conclusions/Significance: Ecosystem services from green roofs can be improved by

planting certain life-form groups in combination, directly contributing to climate change

mitigation and adaptation strategies. The strong performance by certain mixtures of life-forms,

especially tall forbs, grasses and succulents, warrants further investigation into niche

complementarity or facilitation as mechanisms governing biodiversity-ecosystem functioning

relationships in green roof ecosystems.

Lin, B. S. and Y. J. Lin (2010). "Cooling effect of shade trees with different characteristics

in a subtropical urban park." HortScience 45.

The effect of shade trees on the air and surface-soil temperature reduction under the

canopy was studied in a park in subtropical Taipei City, Taiwan. Ten species of trees and two

species of bamboo, which had tightly clustered tall stems and spreading branches resembling

trees in shape, were chosen for the study. In the summer of 2007, we measured leaf and canopy

characteristics of each species. The microclimate conditions under the tree canopies and an

unshaded open space were measured repeatedly at middays without precipitation. In comparison

with the nearby unshaded open space, air temperatures under the canopies were 0.64 to 2.52 °C

lower, whereas the surface-soil temperatures were 3.28 to 8.07 °C lower. Regression analysis

revealed the relative contributions to air cooling effect by the plant's leaf color lightness, foliage

density, leaf thickness, and leaf texture (surface roughness) in decreasing order. Foliage density

had the greatest contribution to surface-soil cooling followed by leaf thickness, leaf texture, and

leaf color lightness in that order. Regression analysis also revealed that solar radiation, wind

velocity, and vapor pressure at the site had significant effects on temperature reduction

attributable to shade trees or bamboo.

Jeon, J. Y., et al. (2010). "Perceptual assessment of quality of urban soundscapes with

combined noise sources and water sounds." J Acoust Soc Am 127.

In this study, urban soundscapes containing combined noise sources were evaluated

through field surveys and laboratory experiments. The effect of water sounds on masking urban

noises was then examined in order to enhance the soundscape perception. Field surveys in 16

urban spaces were conducted through sound-walking to evaluate the annoyance of combined

noise sources. Synthesis curves were derived for the relationships between noise levels and the

percentage of highly annoyed %HA and the percentage of annoyed %A for the combined noise

sources. Qualitative analysis was also made using semantic scales for evaluating the quality of

the soundscape, and it was shown that the perception of acoustic comfort and loudness was

strongly related to the annoyance. A laboratory auditory experiment was then conducted in order

to quantify the total annoyance caused by road traffic noise and four types of construction noise.

It was shown that the annoyance ratings were related to the types of construction noise in

combination with road traffic noise and the level of the road traffic noise. Finally, water sounds

were determined to be the best sounds to use for enhancing the urban soundscape. The level of

the water sounds should be similar to or not less than 3 dB below the level of the urban noises.

Goddard, M. A., et al. (2010). "Scaling up from gardens: biodiversity conservation in

urban environments." Trends Ecol Evol 25(2): 90-98.

As urbanisation increases globally and the natural environment becomes increasingly

fragmented, the importance of urban green spaces for biodiversity conservation grows. In many

countries, private gardens are a major component of urban green space and can provide

considerable biodiversity benefits. Gardens and adjacent habitats form interconnected networks

and a landscape ecology framework is necessary to understand the relationship between the

spatial configuration of garden patches and their constituent biodiversity. A scale-dependent

tension is apparent in garden management, whereby the individual garden is much smaller than

the unit of management needed to retain viable populations. To overcome this, here we suggest

mechanisms for encouraging 'wildlife-friendly' management of collections of gardens across

scales from the neighbourhood to the city.

Georgi, J. N. and D. Dimitriou (2010). "The contribution of urban green spaces to the

improvement of environment in cities: Case study of Chania, Greece." Building and

Environment 45(6): 1401-1414.

This paper investigates how vegetation, mainly through evapotranspiration, affects the

improvement of microclimatic conditions in urban areas and, more specifically, it examines the

case for the city of Chania in Crete. The objectives of this study are to examine the bioclimatic

role of green areas in urban sites as they affect the thermal comfort of residents, and to study the

cross-correlation of factors that participate in this process.

To achieve these objectives, we have examined the parameters that contribute to the

microclimate of a space and consider how it is influenced by vegetation. In addition, we have

analyzed the effect of vegetation with respect to evapotranspiration, and have recorded the

existing vegetation of Chania city and the relationship with the geomorphologic and urban

characteristics of the city. This has involved calculating the evapotranspiration of various plant

species, and collecting measurements at various places in Chania. These studies are designed to

determine the cause of the changes of thermal comfort in different parts of the city, and to

examine the differentiation of thermal comfort that is observed between different plant species

with respect to the evapotranspiration measure that has been calculated for each of them. The

intention of this work is to aid efforts to improve the environment of Chania through better

planning and the appropriate choice of the species used for planting open spaces. Finally, it is

hoped that the results of this work will be of use in planning the environments of spaces in other

cities that have similar characteristics.

Dvorak, B. and A. Volder (2010). "Green roof vegetation for North American ecoregions:

A literature review." Landscape and Urban Planning 96(4): 197-213.

A green roof is a vegetated roof or deck designed to provide urban greening for buildings,

people, or the environment. Made popular across Europe over the past few decades, green roofs

are now becoming more familiar to North Americans as some cities have built green roof pilot

projects and adopted incentives for using green roofs or even require their use. Green roof

standards and guidelines are also emerging to be used for governance and project specification.

Although much is known about the application of green roofs across Europe, much less is known

about their application across North America's diverse ecological regions. When considering the

many decisions required in applying green roof technology to a specific place, there are few

choices more critical to their success than the selection of appropriate vegetation. We conducted

a review of green roof research to investigate what is known about the application of plants on

green roofs across North America and their ecological implications. Results indicate that

investigation sites across ecoregions begin to reveal differences in plant survival. Although

ecological investigations are limited, their results show improved plant performance and

ecological services with diverse green roofs. We conclude that as green roofs continue to become

regulated and adopted in policy, further development of standards and guidelines is needed. To

date, there is no common ground for reporting of green roof research, and we make

recommendations for facilitating such efforts for improved research, policy development and

their management across North America's diverse ecological regions.

Dennis, J. H., et al. (2010). "Sustainable Production Practices Adopted by Greenhouse and

Nursery Plant Growers." HortScience 45(8): 1232-1237.

Given recent consumer and market interest in more sustainable products and business

practices, researchers conducted a nationwide survey of greenhouse and nursery crop growers to

determine the current state of the industry in terms of sustainability. Growers were asked about

the importance of sustainability, their views of state environmental regulations, sustainable

practices in place and ones they would like to implement in the next 1 to 3 years, and interest in

sustainable certification. None of the grower respondents in this survey were certified

sustainable, but at least one fourth (25.8%) were interested in certification. More than half of the

respondents currently recycle plastic pots, use controlled-release fertilizers, and composted plant

waste. However, only 12% of growers want to use biodegradable plant containers or implement

water conservation measures into their production system within the next 1 to 3 years. Grower

respondents felt the biggest obstacle toward implementation was the sustainable production

practice would not be compatible with their existing system of production.

Dearborn, D. C. and S. Kark (2010). "Motivations for conserving urban biodiversity."

Conserv Biol 24(2): 432-440.

In a time of increasing urbanization, the fundamental value of conserving urban

biodiversity remains controversial. How much of a fixed budget should be spent on conservation

in urban versus nonurban landscapes? The answer should depend on the goals that drive our

conservation actions, yet proponents of urban conservation often fail to specify the motivation

for protecting urban biodiversity. This is an important shortcoming on several fronts, including a

missed opportunity to make a stronger appeal to those who believe conservation biology should

focus exclusively on more natural, wilder landscapes. We argue that urban areas do offer an

important venue for conservation biology, but that we must become better at choosing and

articulating our goals. We explored seven possible motivations for urban biodiversity

conservation: preserving local biodiversity, creating stepping stones to nonurban habitat,

understanding and facilitating responses to environmental change, conducting environmental

education, providing ecosystem services, fulfilling ethical responsibilities, and improving human

well-being. To attain all these goals, challenges must be faced that are common to the urban

environment, such as localized pollution, disruption of ecosystem structure, and limited

availability of land. There are, however, also challenges specific only to particular goals,

meaning that different goals will require different approaches and actions. This highlights the

importance of specifying the motivations behind urban biodiversity conservation. If the goals are

unknown, progress cannot be assessed.

Day, S. D., et al. (2010). "Tree root ecology in the Urban environment and implications for

a sustainable rhizosphere." Arboriculture Urban Forestry 36.

This review examines current understandings of how the belowground characteristics of

urban settings affect tree roots as well as how tree roots contribute to biogeochemical processes

in this belowground environment. Soil characteristics common to the urban environment include

soil compaction and other physical impediments to root exploration, elevated pH, altered

temperature and moisture patterns, and the presence of contaminants. These conditions may alter

the growth dynamics, morphology, and physiology of roots. At the same time, roots have a

profound effect on the soil environment, with trees directing 40%–73% of assimilated carbon

below ground. Urban rhizosphere ecology is a topic of renewed interest for research not only

because of its critical role in the urban ecosystem, but also because of its role in global

environmental issues. In addition to its obvious contribution to aboveground growth, root

exploration of the soil environment can influence environmental sustainability through root

contributions to soil structure and drainage. Root influence is further mediated by the intimate

role of roots in soil biological activity and thus carbon storage and nutrient cycling. Current

advances and implications for emerging research are discussed.

Bassuk, N. and P. Trowbridge (2010). "Creating the Urban Eden: Sustainable Landscape

Establishment in Theory and Practice." HortTechnology 20(3): 485-486.

Creating the Urban Eden, a course taught jointly by faculty in Landscape Architecture

and Horticulture at Cornell University, is a unique two-semester class spanning the academic

year from August to May. Students face the task of creating viable, sustainable landscapes both

in theory and practice. The success and sustainability of any planting design is ultimately

dependent upon knowledgeable site assessment and analysis, appropriate plant selection, and

clear communication of design intentions. This class teaches all aspects of landscape

establishment, including detailed site assessment, woody plant identification, choice of

appropriate plants, planting design, soil remediation, transplanting, and early maintenance in

human-impacted landscapes. In addition to designing for a specific site, students learn about

written specifications for technical planting and graphic details to communicate and implement

design proposals. Every year on the Cornell University campus, the students in this class

implement, in a hands-on manner, all aspects of landscape establishment that they have learned

by creating new landscapes that serve to integrate theory, principles, practice, and provide a

demonstration of fundamentals taught in the class.

Behe, B. K., Campbell, B., Dennis, J., Hall, C., Lopez, R., & Yue, C. (2010). "Gardening

consumer segments vary in ecopractices."

Savvy marketers rely on the principles of customer segmentation and product targeting to

more efficiently allocate scarce resources and effectively reach groups of consumers with similar

likes, preferences, or demands. Our objective was to identify and profile consumer segments

with regard to their gardening purchases to determine whether there were differences in their

ecofriendly attitudes and behaviors such as recycling. Our underlying hypothesis was that

different types of gardeners may exhibit more environmentally friendly behavior, predisposing

them to be more receptive to product innovations specifically designed to be ecofriendly.

Researchers collected plant purchases, recycling attitudes and behaviors, and preferences for

ecofriendly containers from 763 consumers in Indiana, Michigan, Minnesota, and Texas. A

cluster analysis based on plant purchases yielded three consumer segments: low use, woody plant

buyers, and herbaceous plant buyers. There were some differences with regard to recycling

behaviors among consumers in the three groups, including recycling aluminum drinking cans,

newspapers, magazines, use of energy-saving bulbs, and composting yard waste. Generally,

herbaceous plant buyers were most ecofriendly followed by woody plant buyers and low use.

Given these differences, there appears to be some merit in the future to segment consumers by

plant purchases versus others to target specific types of ecofriendly products to them.

Yang, D. S., et al. (2009). "Screening Indoor Plants for Volatile Organic Pollutant Removal

Efficiency." HortScience 44(5): 1377-1381.

Twenty-eight ornamental species commonly used for interior plantscapes were screened

for their ability to remove five volatile indoor pollutants: aromatic hydrocarbons (benzene and

toluene), aliphatic hydrocarbon (octane), halogenated hydrocarbon [trichloroethylene (TCE)],

and terpene ({alpha}-pinene). Individual plants were placed in 10.5-L gas-tight glass jars and

exposed to {approx}10 ppm (31.9, 53.7, 37.7, 46.7, and 55.7 mg{middle dot}m-3) of benzene,

TCE, toluene, octane, and{alpha} -pinene, respectively. Air samples (1.0 mL) within the glass

containers were analyzed by gas chromatography-mass spectroscopy 3 and 6 h after exposure to

the test pollutants to determine removal efficiency by monitoring the decline in concentration

over 6 h within sealed glass containers. To determine removal by the plant, removal by other

means (glass, plant pot, media) was subtracted. The removal efficiency, expressed on a leaf area

basis for each volatile organic compound (VOC), varied with plant species. Of the 28 species

tested, Hemigraphis alternata, Hedera helix, Hoya carnosa, and Asparagus densiflorus had the

highest removal efficiencies for all pollutants; Tradescantia pallida displayed superior removal

efficiency for four of the five VOCs (i.e., benzene, toluene, TCE, and{alpha} -pinene). The five

species ranged in their removal efficiency from 26.08 to 44.04 {micro}g{middle dot}m-

3{middle dot}m-2{middle dot}h-1 of the total VOCs. Fittonia argyroneura effectively removed

benzene, toluene, and TCE. Ficus benjamina effectively removed octane and{alpha} -pinene,

whereas Polyscias fruticosa effectively removed octane. The variation in removal efficiency

among species indicates that for maximum improvement of indoor air quality, multiple species

are needed. The number and type of plants should be tailored to the type of VOCs present and

their rates of emanation at each specific indoor location.

Tait, R. J., et al. (2009). "An electronic tree inventory for arboriculture management."

Knowledge-Based Systems 22(7): 552-556.

The integration of Global Positioning System (GPS) technology into mobile devices

provides them with an awareness of their physical location. This geospatial context can be

employed in a wide range of applications including locating nearby places of interest as well as

guiding emergency services to incidents. In this research, a GPS-enabled Personal Digital

Assistant (PDA) is used to create a computerised tree inventory for the management of

arboriculture. Using the General Packet Radio Service (GPRS), GPS information and arboreal

image data are sent to a web-server. An office-based PC running customised Geographical

Information Software (GIS) then automatically retrieves the GPS tagged image data for display

and analysis purposes. The resulting application allows an expert user to view the condition of

individual trees in greater detail than is possible using remotely sensed imagery.

Stewart, G. H., et al. (2009). "URban Biotopes of Aotearoa New Zealand (URBANZ) II:

Floristics, biodiversity and conservation values of urban residential and public woodlands,

Christchurch." Urban Forestry & Urban Greening 8(3): 149-162.

Urban forests are increasingly valued for multiple benefits such as amenity, cultural

values, native biodiversity, ecosystem services, and carbon sequestration. Urban biodiversity in

particular, is the new focus although global homogenisation is undermining regional

differentiation. In the northern hemisphere (e.g., Canada and USA) and in the southern

hemisphere, particularly in countries like South Africa, Australia, South America and New

Zealand, local biodiversity is further impacted by historical colonisation from Europe. After

several centuries, urban forests are now composed of synthetic and spontaneous mixtures of

native species, and exotic species from around the temperate world (e.g., Europe, North and

South America, South Africa, Asia). As far as we are aware no-one has carried out in-depth

study of these synthetic forests in any Southern Hemisphere city. Here we describe the

composition, structure, and biodiversity conservation imperatives of urban temperate forests at

90 random locations in Christchurch city, New Zealand. We document considerable plant

diversity; the total number of species encountered in the 253 sampled urban forest patches was

486. Despite this incredibly variable data set, our ability to explain variation in species richness

was surprisingly good and clearly indicates that total species richness was higher in larger

patches with greater litter and vegetation cover, and taller canopy height. Species richness was

also higher in patches surrounded by higher population densities and closer to very large native

forest patches. Native species richness was higher in patches with higher soil pH, lower canopy

height, and greater litter cover and in patches closer to very large native forest patches indicating

dispersal out of native areas and into gardens. Eight distinct forest communities were identified

by Two-Way INdicator SPecies ANalysis (TWINSPAN) using the occurrence of 241 species

that occurred in more than two out of all 253 forest patches. Christchurch urban forest canopies

were dominated by exotic tree species in parklands and in street tree plantings (linear parkland).

Native tree and shrub species were not as common in public spaces but their overall density high

in residential gardens. There was some explanatory power in our data, since less deprivation

resulted in greater diversity and density, and more native species, which in turn is associated

with private ownership. We hypothesise that a number of other factors, which were not well

reflected in our measured environmental variables, are responsible for much of the remaining

variation in the plant community structure, e.g., advertising, peoples choice. For a more

sustainable asset base of native trees in New Zealand cities we need more, longer-lived native

species, in large public spaces, including a greater proportion of species that bear fruit and nectar

suitable for native wildlife. We may then achieve cities with ecological integrity that present

multiple historical dimensions, and sequester carbon in legible landscapes.

Sanford, M. P., et al. (2009). "Effects of Urban Development on Ant Communities:

Implications for Ecosystem Services and Management." Conservation Biology 23(1): 131-

141.

Research that connects the effects of urbanization on biodiversity and ecosystem services

is lacking. Ants perform multifarious ecological functions that stabilize ecosystems and

contribute to a number of ecosystem services. We studied responses of ant communities to

urbanization in the Lake Tahoe basin by sampling sites along a gradient of urban land

development. We sampled ant communities, measured vegetation characteristics, quantified

human activities, and evaluated ant-community responses by grouping ants into service-

providing units (SPUs), defined as a group of organisms and their populations that perform

specific ecosystem services, to provide an understanding of urbanization impacts on biodiversity

and their delivery of ecosystem services. Species richness and abundance peaked at intermediate

levels of urban development, as did the richness of 3 types of ant SPUs (aerators, decomposers,

and compilers). With increasing land development aerator and decomposer ants significantly

declined in abundance, whereas compiler ants significantly increased in abundance. Competing

models demonstrated that precipitation was frequently among the strongest influences on ant

community structure; however, urban development and human activities also had a strong,

negative influence on ants, appearing in most models with Delta AIC(c) < 2 for species richness

and abundance patterns of SPUs and generalists. Response diversity was observed within SPUs,

which suggests that the corresponding ecosystem services were maintained until development

reached 30-40%. Our data provide evidence that ecosystem functions, such as water infiltration

and soil productivity, may be diminished at sites subject to greater levels of urbanization and that

conserving ant communities and the ecosystem services they provide could be an important

target in land-use planning and conservation efforts.

Rosenzweig, C., et al. (2009). "Mitigating New York City’s Heat Island: integrating

stakeholder perspectives and scientific evaluation." Bull Am Meteorol Soc 90.

The urban heat island effect1 can be detected throughout the year, but it is of particular

pub- lic policy concern during the summer, because higher surface air temperature is associated

with increases in electricity demand for air conditioning, air pollution, and heat stress-related

mortality and illness (Rosenfeld et al. 1995; Nowak et al. 2000; Sailor et al. 2002; Hogrefe et al.

2004). In New York City, New York (NYC), the heat island impacts interact with aging energy

and water infrastructure and the anticipated regional effects of global climate change. This has

led local decision makers to ask whether heat island mitigation can help to address some

of these related urban challenges, for example, by reducing electricity demand for cooling,

absorbing stormwater runoff, and reducing the health impacts of heat waves.

Our main goal was to compare the possible effectiveness of heat island mitigation

strategies to increase urban vegetation, such as planting trees or incorporating vegetation into

rooftops, with strategies to increase the albedo of impervious surfaces. The specific stakeholder

question guiding our research was the following: can heat island mitigation strate- gies reduce

peak electricity demand in neighbor- hoods with potential electric distribution constraints

Randhir, T. and P. Ekness (2009). "Urbanization effects on watershed habitat potential: a

multivariate assessment of thresholds and interactions." Ecohydrology 2(1): 88-101.

A watershed-based assessment is used to assess the effect of urbanization on vertebrate

habitat potential in Westfield River Watershed in Massachusetts, USA. A spatial analysis is used

to develop urban indicators and habitat potential for each subbasin in the watershed. It is

observed that threshold effect of urbanization on habitat potential of vertebrates is at 10 to 12

percent impervious cover. Amphibian habitat is influenced by available open space and land use

disturbance in the watershed. The reptile habitat is sensitive to impervious coverage and land use

disturbance, and decreased with fragmentation. The habitat for birds is influenced by land use

disturbance, human population densities, size of forest patch, and open space in the watershed.

Mammal habitat is influenced by human population density, land use disturbance, and

fragmentation. A watershed-based assessment is useful to identify critical areas of high urban

influence. Threshold values and nature of interactions between urbanization and habitat are

assessed and used in policy recommendations. Policies and practices that minimize effects of

urbanization in the watershed include impervious taxes, zoning policies, and open space

protection. The need for provision of education and information on the relationship between

urbanization and habitat potential is emphasized for sustainable use of watershed resources.

Patterson, T. M. and D. L. Coelho (2009). "Ecosystem services: Foundations, opportunities,

and challenges for the forest products sector." Forest Ecology and Management 257(8):

1637-1646.

The ecosystem service concept has been proposed as a meaningful framework for natural

resource management. In theory it holds concomitant benefit and consequence for the forest

product sector. However, numerous barriers impede practitioners from developing concrete and

enduring responses to emerging ecosystem service markets, policies, and initiatives. Principle

among these barriers is that the ecosystem service concept has a complex history, numerous

definitions in use, and an astounding diversity in rationale and application. This article provides a

conceptual review of ecosystem services and its economic foundations, distinguishes among

several current definitions of the term and their relatedness to strategies in practical application,

discusses diverse approaches to valuation, and explores potential for future relevance in forest

product and other sectors.

Paoletti, E. (2009). "Ozone and urban forests in Italy." Environmental Pollution 157(5):

1506-1512.

Ozone levels along urban-to-rural gradients in three Italian cities (Milan, Florence, Bari)

showed that average AOT40 values at rural and suburban sites were 2.6 times higher than those

determined at urban sites. However, O-3 also exceeded the European criteria to protect forest

health at urban sites, even when the standards for human health protection were met. For

protecting street trees in Mediterranean cities, the objectives of measurement at urban sites

should extend from the protection of human health to the protection of vegetation as well. A

review of forest effects on O-3 pollution and of O-3 pollution on forest conditions in Italian cities

showed that it was not possible to distinguish the effect of O-3 in the complex mixture of urban

pollutants and stressors. A preliminary list of tree species for urban planning in the

Mediterranean area shows the average tree capacity of O-3 removal and VOC emission.

Musacchio, L. (2009). "The scientific basis for the design of landscape sustainability: A

conceptual framework for translational landscape research and practice of designed

landscapes and the six Es of landscape sustainability." Landscape Ecology 24(8): 993-1013.

Landscape researchers and practitioners, using the lens of sustainability science, are

breaking new ground about how people’s behaviors and actions influence the structure, function,

and change of designed landscapes in an urbanizing world. The phrase—the scientific basis of

the design for landscape sustainability—is used to describe how sustainability science can

contribute to translational landscape research and practice about the systemic relationships

among landscape sustainability, people’s contact with nature, and complex place-based

problems. In the first section of this article, important definitions about the scientific basis of the

design for landscape sustainability are reviewed including the six Es of landscape sustainability—environment, economic, equity, aesthetics, experience, and ethics. A conceptual framework

about the six Es of landscape sustainability for designed landscapes is introduced. The

interrelatedness, opportunities, contradictions, and limitations of the conceptual framework are

discussed in relation to human health/security, ecosystem services, biodiversity, and resource

management. The conceptual framework about the six Es of landscape sustainability for

designed landscapes follows the tradition in which landscape researchers and practitioners

synthesize emerging trends into conceptual frameworks for advancing basic and applied

activities.

Marks, B. K. and R. S. Duncan (2009). "Use of Forest Edges by Free-ranging Cats and

Dogs in an Urban Forest Fragment." Southeastern Naturalist 8(3): 427-436.

Free-ranging Felis catus (Domestic Cat) and Canis familiaris (Domestic Dog) can greatly

impact native prey populations, but little is known about their occurrence in urban forest

fragments. In this study, we used camera traps to photograph (capture) cats, dogs, and native

wildlife in a 409-ha urban forest in Birmingham, AL from Jan-Apr 2007. Habitat treatments

included forest interior and forest edges by industrial lands, neighborhoods with higher house

values, and neighborhoods with lower house values. We employed both conservative (n = 31)

and liberal (n = 64) methods of tallying the number of individual dogs, cats, and native mammals

captured. Dogs and cats combined comprised 19% (conservative) and 26% (liberal) of all

photographic captures. Procyon lotor (Raccoon) were the most abundant of the 7 native species

at 32% (conservative) and 53% (liberal) of all captures. Dogs were more abundant in

neighborhood edges, and cats were more abundant in the forest interior. Cats and dogs combined

were 75% (conservative) and 86% (liberal) of captures from the forest interior. Captures of

native species were far more frequent in neighborhood edges (conservative = 86.9%, and liberal

= 92.3%) than in other treatments. These findings demonstrate that exotic predators can be an

important ecological presence in certain portions of urban forest fragments, and more extensive

studies of their impact are needed.

Maas, J., et al. (2009). "Morbidity is related to a green living environment." Journal of

Epidemiology and Community Health 63(12): 967-973.

Background: As a result of increasing urbanisation, people face the prospect of living in

environments with few green spaces. There is increasing evidence for a positive relation between

green space in people's living environment and self-reported indicators of physical and

mental health. This study investigates whether physician assessed morbidity is also related to

green space in people's living environment.

Methods: Morbidity data were derived from electronic medical records of 195 general

practitioners in 96 Dutch practices, serving a population of 345 143 people. Morbidity was

classified by the general practitioners according to the International Classification of Primary

Care. The percentage of green space within a 1 km and 3 km radius around the postal code

coordinates was derived from an existing database and was calculated for each household.

Multilevel logistic regression analyses were performed, controlling for demographic and socio

economic characteristics.

Results: The annual prevalence rate of 15 of the 24 disease clusters was lower in living

environments with more green space in a 1 km radius. The relation was strongest for anxiety

disorder and depression. The relation was stronger for children and people with a lower

socioeconomic status. Furthermore, the relation was strongest in slightly urban areas and not

apparent in very strongly urban areas.

Conclusion: This study indicates that the previously established relation between green

space and a number of self-reported general indicators of physical and mental health can also be

found for clusters of specific physician assessed morbidity. The study stresses the importance of

green space close to home for children and lower socioeconomic groups.

Lorenz, K. and R. Lal (2009). "Biogeochemical C and N cycles in urban soils."

Environment International 35(1): 1-8.

The percentage of urban population is projected to increase drastically. In 2030, 50.7 to

86.7% of the total population in Africa and Northern America may live in urban areas,

respectively. The effects of the attendant increases in urban land uses on biogeochemical C and

N cycles are, however, largely unknown. Biogeochemical cycles in urban ecosystems are altered

directly and indirectly by human activities. Direct effects include changes in the biological,

chemical and physical soil properties and processes in urban soils. Indirect effects of urban

environments on biogeochemical cycles may be attributed to the introductions of exotic plant

and animal species and atmospheric deposition of pollutants. Urbanization may also affect the

regional and global atmospheric climate by the urban heat island and pollution island effect. On

the other hand, urban soils have the potential to store large amounts of soil organic carbon (SOC)

and, thus, contribute to mitigating increases in atmospheric CO2 concentrations. However, the

amount of SOC stored in urban soils is highly variable in space and time. and depends among

others on soil parent material and land use. The SOC pool in 0.3-m depth may range between 16

and 232 Mg ha(-1), and between 15 and 285 Mg ha(-1) in 1-m depth. Thus, depending on the

soil replaced or disturbed, urban soils may have higher or lower SOC pools, but very little is

known. This review provides an overview of the biogeochemical cycling of C and N in urban

soils, with a focus on the effects of urban land use and management on soil organic matter

(SOM). In view of the increase in atmospheric CO2 and reactive N concentrations as a result of

urbanization, urban land use planning must also include strategies to sequester C in soil, and also

enhance the N sink in urban soils and vegetation. This will strengthen soil ecological functions

such as retention of nutrients, hazardous compounds and water, and also improve urban

ecosystem services by promoting soil fertility.

Lo, R. H. (2009). "Walkability: what is it?" J Urbanism 2.

The literature shows single-use, low-density land development and disconnected street

networks to be positively associated with auto dependence and negatively associated with

walking and transit use. These factors in turn appear to affect health by influencing physical

activity, obesity, and emissions of air pollutants. We evaluated the association between a single

index of walkability that incorporated land use mix, street connectivity, net residential density,

and retail floor area ratios, with health-related outcomes in King County, Washington. We found

a 5% increase in walkability to be associated with a per capita 32.1% increase in time spent in

physically active travel, a 0.23-point reduction in body mass index, 6.5% fewer vehicle miles

traveled, 5.6% fewer grams of oxides of nitrogen (NOx) emitted, and 5.5% fewer grams of

volatile organic compounds (VOC) emitted. These results connect development patterns with

factors that affect several prevalent chronic diseases.

Kenwick, R. A., et al. (2009). "Preferences for riparian buffers." Landscape and Urban

Planning 91(2): 88-96.

Intensive management of riparian zones in the Mid-Western United States has long

involved clearing vegetation, straightening meandering streams, and lining earthen banks with

stone or concrete. Recently. however, scholars have begun to document the ecological costs of

such practices. Replacing barren stream edges with more natural alternatives such as vegetated

buffers can improve the visual appeal, environmental services, and ecological health of these

ecosystems. Despite their potential benefits. these alternatives are rarely employed. Is it because

individual landowners dislike these management strategies or is it that professional planners

disapprove of such options? This paper examines the approval of various riparian buffer types by

landowners and planners in Illinois using a photo-questionnaire. Participants rated their

preferences for tree buffers, grass buffers, and a 'no buffer' condition along waterways in rural

and suburban landscapes. They also rated their preferences for meandering streams in rural areas

and earthen banks in the suburbs. The results show substantial support for tree buffers by both

residents and planners. Participants also demonstrated considerable approval for meandering

streams in rural areas. These findings add to the growing body of literature on preferences for

buffers in different landscape settings and provide ample evidence for planners and policy-

makers to take necessary steps to preserve or restore vegetated riparian buffers and meandering

channels along Mid-western waterways. These natural alternatives to existing strategies are not

only visually attractive and ecologically beneficial. they are also positive steps towards more

sustainable riparian management practices.

Kalansuriya CM, P. A., Sonnadara DU. (2009). Effect of roadside vegetation on the

reduction of traffic noise levels. In Proceedings of the Technical Sessions – Institute of

Physics.

A study was carried out to determine the effect of roadside vegetation on the reduction of

road traffic noise levels under varying traffic conditions. Roadside vegetation which have the

potential to act as noise barriers were selected for this study. The road traffic noise was measured

together with the parameters that control the vegetation. Several noise level descriptors were

recorded together with the A-weighted continuous noise level.

The results show that higher frequency noise (above 4 kHz) is heavily attenuated by the

vegetation barriers with virtually no attenuation for low frequency noise (below 100 Hz). The

width of the vegetation barrier is linearly proportional to the amount of sound absorption.

Without the vegetation barrier, the observed maximum and minimum noise levels were 72 dB(A)

and 64 dB(A) respectively. On average, vegetation barriers were able to reduce the noise by 4

dB(A) which corresponds to an approximately 40% acoustic energy reduction. Thus, with careful

planning and growing of roadside vegetation, the effect of road noise can be reduced.

James, P., et al. (2009). "Towards an integrated understanding of green space in the

European built environment." Urban Forestry & Urban Greening 8(2): 65-75.

In recent years social, economic and environmental considerations have led to a

reevaluation of the factors that contribute to sustainable urban environments. Increasingly, urban

green space is seen as an integral part of cities providing a range of services to both the people

and the wildlife living in urban areas. With this recognition and resulting from the simultaneous

provision of different services, there is a real need to identify a research framework in which to

develop multidisciplinary and interdisciplinary research on urban green space. In order to

address these needs, an iterative process based on the delphi technique was developed, which

comprised email-mediated discussions and a two-day symposium involving experts from various

disciplines. The two outputs of this iterative process were (i) an integrated framework for

multidisciplinary and interdisciplinary research and (ii) a catalogue of key research questions in

urban green space research. The integrated framework presented here includes relevant research

areas (i.e. ecosystem services, drivers of change, pressures on urban green space, human

processes and goals of provision of urban green space) and emergent research themes in urban

green space studies (i.e. physicality, experience, valuation, management and governance).

Collectively these two outputs have the potential to establish an international research agenda for

urban green space, which can contribute to the better understanding of people's relationship with

cities.

Gherardi, M., et al. (2009). "Heavy metals in the soil-plant system: monitoring urban and

extra-urban parks in the Emilia Romagna Region (Italy)." Agrochimica 53(3): 196-208.

For each of three Emilia Romagna Region (Italy) cities (Bologna. Ferrara and Cesena) an

urban park situated in the historical heart of the city and an extra-urban park were selected. The

aim of the study was to assess the concentration of heavy metals and microelements in different

environmental matrixes, namely: soil, leaf tissues of coniferous and deciduous trees, mosses

(spp. Hypnum cupressiforme) and grass, and washed-leaves water. The concentration of heavy

metals (Cd, Co, Cu. Cr, Ni, Pb, Zn) was detected using an ICP-OE Spectrometer. For sampling

point of Massari park in Ferrara city (FE-M1) and of Giardini Margherita park in Bologna city

(BO-M3) heavy metals concentrations exceeded the threshold values established by the current

Italian laws for soils of "public, residential and private areas" (D. Lgs 152/2006). The correlation

between the concentration values of top- and subsoil highlights that some elements, such as Cd,

Cu, Pb and Zn, have an anthropic origin and are mainly linked to the deposition of airborne

pollutants, while other elements (Co, Cr and Ni) have a lithologic origin. The study of mosses,

grass and the washed-leaves water made it possible to identify seasonal variations of pollutants

deposition and, furthermore, to calculate the enrichment coefficient and the accumulation of

heavy metals over time.

Getter, K. L., et al. (2009). "Carbon Sequestration Potential of Extensive Green Roofs."

Environmental Science & Technology 43(19): 7564-7570.

Two studies were conducted with the objective of quantifying the carbon storage

potential of extensive green roofs. The first was performed on eight roofs in Michigan and four

roofs in Maryland, ranging from 1 to 6 years in age. All 12 green roofs were composed primarily

of Sedum species, and substrate depths ranged from 2.5 to 12.7 cm. Aboveground plant material

was harvested in the fall of 2006. On average, these roofs stored 162 g C·m−2 in aboveground

biomass. The second study was conducted on a roof in East Lansing, MI. Twenty plots were

established on 21 April 2007 with a substrate depth of 6.0 cm. In addition to a substrate only

control, the other plots were sown with a single species of Sedum (S. acre, S. album, S.

kamtshaticum, or S. spurium). Species and substrate depth represent typical extensive green

roofs in the United States. Plant material and substrate were harvested seven times across two

growing seasons. Results at the end of the second year showed that aboveground plant material

storage varied by species, ranging from 64 g C·m−2 (S. acre) to 239 g C·m−2 (S. album), with

an average of 168 g C·m−2. Belowground biomass ranged from 37 g C·m−2 (S. acre) to 185 g

C·m−2 (S. kamtschaticum) and averaged 107 g C·m−2. Substrate carbon content averaged 913 g

C·m−2, with no species effect, which represents a sequestration rate of 100 g C·m−2 over the 2

years of this study. The entire extensive green roof system sequestered 375 g C·m−2 in above-

and belowground biomass and substrate organic matter.

Escobedo, F. J. and D. J. Nowak (2009). "Spatial heterogeneity and air pollution removal

by an urban forest." Landscape and Urban Planning 90(3-4): 102-110.

Estimates of air pollution removal by the urban forest have mostly been based on mean

values of forest structure variables for an entire city. However, the urban forest is not uniformly

distributed across a city because of biophysical and social factors. Consequently, air pollution

removal function by urban vegetation should vary because of this spatial heterogeneity. This

paper presents a different approach to evaluate how the spatial heterogeneity of the urban forest

influences air pollution removal at the socioeconomic subregion scale. Air pollution removal for

July 1997 to June 1998 and July 2000 to June 2001 were estimated using measured urban forest

structure data from three socioeconomic subregions in Santiago, Chile. Dry deposition was

estimated using hourly climate, mixing height, and pollutant concentration data. Pollution

removal rates among the three socioeconomic subregions were different because of

heterogeneous urban forest structure and pollution concentrations. Air pollution removal per

square meter of tree cover was greatest in the low socioeconomic subregion. Pollution removal

during 1997-1998 was different from 2000 to 2001 due to pollution concentration differences.

Seasonal air quality improvement also differed among the subregions. Results can be used to

design management alternatives at finer administrative scales such as districts and

neighborhoods that maximize the pollution removal rates by the urban forest in a subregion.

Policies that affect the functionality of urban forest structure must consider spatial heterogeneity

and scale when making region-wide recommendations. Similarly, when modeling the

functionality of the urban forest, models must capture this spatial heterogeneity for inter-city

comparisons.

Dwivedi, P., et al. (2009). "Ecological benefits of urban forestry: The case of Kerwa Forest

Area (KFA), Bhopal, India." Applied Geography 29(2): 194-200.

In developing countries like India, migration of people from rural to urban areas is

responsible for ever expanding urban boundaries. This trend is exerting significant pressure on

unprotected natural forests located near urban centers. This paper highlights the case of Kerwa

Forest Area (KFA), located at about 10 km from the city of Bhopal, capital of Madhya Pradesh

state. The objectives of this study are to quantify the extent of disturbance faced and ecosystem

services provided by the KFA. Suitable spatial technologies and forest sampling techniques have

been used to achieve the objectives of the study. It was found that the KFA is currently facing

severe anthropogenic pressure. Parts of the KFA, located close to the settlements, were found

more disturbed than the parts which were located far from the settlements. In spite of

disturbances, KFA is a habitat for many threatened and endangered plant, animal, and bird

species. KFA also plays a critical role of a carbon sink with a total storage of about 19.5

thousand tons of aboveground carbon. Immediate precautionary measures are required to prevent

further degradation of the KFA for ensuring better environmental quality for the residents of

Bhopal city in the future.

Davies, Z. G., et al. (2009). "A national scale inventory of resource provision for

biodiversity within domestic gardens." Biological Conservation 142(4): 761-771.

The human population is increasingly disconnected from nature due to urbanisation. To

counteract this phenomenon, the UK government has been actively promoting wildlife

gardening. However, the extent to which such activities are conducted and the level of resource

provision for biodiversity (e.g., food and nesting sites) within domestic gardens remains poorly

documented. Here we generate estimates for a selection of key resources provided within

gardens at a national scale, using 12 survey datasets gathered across the UK. We estimate that

22.7 million households (87% of homes) have access to a garden. Average garden SiZe is 190

m(2), extrapolating to a total area of 432,924 ha. Although substantial, this coverage is still an

order of magnitude less than that of statutory protected areas. Approximately 12.6 million (48%)

households provide supplementary food for birds, 7.4 million of which specifically use bird

feeders. Similarly, there are a minimum of 4.7 million nest boxes within gardens. These figures

equate to one bird feeder for every nine potentially feeder-using birds in the UK, and at least one

nest box for every six breeding pairs of cavity nesting birds. Gardens also contain 2.5-3.5 million

ponds and 28.7 million trees, which is just under a quarter of all trees occurring outside

woodlands. Ongoing urbanisation, characterised by increased housing densities, is inevitable

throughout the UK and elsewhere. The important contribution domestic gardens make to the

green space infrastructure in residential areas must be acknowledged, as their reduction will

impact biodiversity conservation, ecosystem services, and the well-being of the human

population.

Burghardt, K. T., et al. (2009). "Impact of Native Plants on Bird and Butterfly Biodiversity

in Suburban Landscapes." Conservation Biology 23(1): 219-224.

Managed landscapes in which non-native ornamental plants are favored over native

vegetation now dominate the United States, particularly east of the Mississippi River. We

measured how landscaping with native plants affects the avian and lepidopteran communities on

6 pairs of suburban properties in southeastern Pennsylvania. One property in each pair was

landscaped entirely with native plants and the other exhibited a more conventional suburban

mixture of plants2014a native canopy with non-native groundcover and shrubs. Vegetation

sampling confirmed that total plant cover and plant diversity did not differ between treatments,

but non-native plant cover was greater on the conventional sites and native plant cover was

greater on the native sites. Several avian (abundance, species richness, biomass, and breeding-

bird abundance) and larval lepidopteran (abundance and species richness) community parameters

were measured from June 2006 to August 2006. Native properties supported significantly more

caterpillars and caterpillar species and significantly greater bird abundance, diversity, species

richness, biomass, and breeding pairs of native species. Of particular importance is that bird

species of regional conservation concern were 8 times more abundant and significantly more

diverse on native properties. In our study area, native landscaping positively influenced the avian

and lepidopteran carrying capacity of suburbia and provided a mechanism for reducing

biodiversity losses in human-dominated landscapes.

Wolf, D. and J. T. Lundholm (2008). "Water uptake in green roof microcosms: Effects of

plant species and water availability." Ecological Engineering 33(2): 179-186.

Green roofs are engineered ecosystems that rely on vegetation to provide services such as

reduction of roof temperatures. Drought resistance is critical for plant survival on shallow-

substrate green roofs, but potential trade-offs exist between water-use efficiency and ecosystem

functions like transpirative cooling. Water loss from simulated green roof systems (microcosms)

each containing 1 of 14 plant species belonging to 4 growth forms (succulents, herbaceous

dicots, grasses and woody creeping shrubs) was quantified for 3 watering treatments (watering to

field capacity every 4, 11 and 24 days). After 2 months only succulents survived the dry

treatment. The dry treatment was the only treatment in which planted microcosms showed

consistently greater water loss (∼30% greater) than the controls (soil-only microcosms).

Microcosms planted with Poa compressa lost the most water in all moisture treatments but in the

wet and intermediate treatments, respectively, native species Rhodiola rosea and Campanula

rotundifolia had equivalent performance to P. compressa. The mat-forming Sedum acre retained

more water than controls and other species in the wet and intermediate treatments suggesting that

its growth form impeded evaporation from the soil surface. Performance differences among

growth forms and species across soil moisture gradients suggest that optimal water loss and roof

surface cooling could be enhanced by planting multiple species.

Whelan, C. J., et al. (2008). Ecosystem Services Provided by Birds.

Ecosystem services are natural processes that benefit humans. Birds contribute the four

types of services recognized by the UN Millennium Ecosystem Assessment2014provisioning,

regulating, cultural, and supporting services. In this review, we concentrate primarily on

supporting services, and to a lesser extent, provisioning and regulating services. As members of

ecosystems, birds play many roles, including as predators, pollinators, scavengers, seed

dispersers, seed predators, and ecosystem engineers. These ecosystem services fall into two

subcategories: those that arise via behavior (like consumption of agricultural pests) and those

that arise via bird products (like nests and guano). Characteristics of most birds make them quite

special from the perspective of ecosystem services. Because most birds fly, they can respond to

irruptive or pulsed resources in ways generally not possible for other vertebrates. Migratory

species link ecosystem processes and fluxes that are separated by great distances and times.

Although the economic value to humans contributed by most, if not all, of the supporting

services has yet to be quantified, we believe they are important to humans. Our goals for this

review are 1) to lay the groundwork on these services to facilitate future efforts to estimate their

economic value, 2) to highlight gaps in our knowledge, and 3) to point to future directions for

additional research.

Van Rossum, F. (2008). "Conservation of long-lived perennial forest herbs in an urban

context: Primula elatior as study case." Conservation Genetics 9(1): 119-128.

Urban forests are generally fragmented in small isolated remnants, embedded in an

inhospitable human-used matrix, and incur strong anthropogenic pressures (recreational

activities, artificialization, pollution and eutrophication). These lead to particularly high

constraints even for common forest herbs, whose genetic response may depend on life-history

traits and population demographic status. This study investigated genetic variation and structure

for 20 allozyme loci in 14 populations of Primula elatior, a self-incompatible long-lived

perennial herb, occurring in forest fragments of Brussels urban zone (Belgium), in relation to

population size and young plants recruitment rate. Urban populations of P. elatior were not

genetically depauperate, but the small populations showed reduced allelic richness. Small

populations showing high recruitment rates-and therefore potential rejuvenation-revealed lower

genetic diversity (H (o) and H (e)) than those with low or no recruitment. No such pattern was

observed for the large populations. There was a significant genetic differentiation among

populations within forest fragments (F (SC) = 0.052, P < 0.001), but not between fragments (F

(CT) = 0.002, P > 0.10). These findings suggest restricted gene flow among populations within

fragments and local processes (genetic drift, inbreeding) affecting small populations,

strengthened when there is recruitment. Urban forest populations of long-lived perennial herbs

can be of conservation value. However, restoration of small populations by increasing population

size through regeneration by seedling recruitment may lead to negative genetic consequences.

Additional management, aiming to restore gene flow among populations, may need to be applied

to compensate the loss of genetic diversity and to reduce inbreeding.

Vallet, J., et al. (2008). "Plant species response to urbanization: comparison of isolated

woodland patches in two cities of North-Western France." Landscape Ecology 23(10):

1205-1217.

The effect of urbanization on species distribution has been extensively documented, but a

main challenge in urban ecology is to better understand the factors causing different distributions

among species in response to urbanization. Hence, this paper aims to compare the effects of

urbanization on woodland plant assemblages in two cities and to describe species responses by

using several indicators. The study was carried out in the cities of Angers and Rennes (North-

Western France) where 11 isolated woodlands were surveyed along an urban-rural gradient in

each city. Abundance data of spontaneous species were collected from 220 quadrats. The effect

of land cover (within a 500 m buffer around each woodland) on species assemblages was

investigated by Canonical Correspondence Analysis. Buildings and pavement areas were the

most significant predictors of species composition, and the effect of location in Angers or

Rennes appeared on the second axis. More than 60% of the most frequent plant species were

indicator of urban or rural location and their preferences were similar in the two cities. These

lists of urban and rural indicator species were compared with Ellenberg's indicator values and

two other indicators specific to forest environment. The species which grow preferentially in

urban woodlands are species which are already known to be associated with recent forests rather

than ancient forests; with hedgerows rather than woodlands. The opposite pattern was observed

concerning rural species. Moreover, urban indicator species have higher optima for soil pH and

soil nitrogen content than rural indicator species. Different characteristics and history of forest

habitat-continuity of the forest land cover, linearity of the habitat, change in adjacent land cover

and land use-could select the same species, and the responses of the latter might involve different

preferences concerning soil alkalinity and nutrient status.

Terho, M. and A. M. Hallaksela (2008). "Decay characteristics of hazardous Tilia, Betula,

and Acer trees felled by municipal urban tree managers in the Helsinki City Area."

Forestry 81(2): 151-159.

In order to improve the management and protection of old urban trees, the decay

characteristics of trees that had been removed as hazardous according to the local management

protocol were investigated. The stage and the cross-sectional extent of decay were examined on a

total of 181 park and street trees in the Helsinki city area: 64 trees of Tilia spp., 58 Betula spp.

and 59 Acer spp. For Tilia, hollowed heartwood with low fungal expression and advanced decay

caused by Ganoderma lipsiense were the two most common characteristics of cross-section

samples from the points where stem breakage was most likely. For Betula, the primary reason for

tree removal was usually lowered amenity value in terms of a declined appearance of the crown.

Advanced decay, mainly caused by Inonotus obliquus, Piptoporus betulinus and Cerrena

unicolor, were the most potential causes for stem breakage on Betula . For Acer, internal cracks,

most often due to weak fork formation, were common causes of potential hazard. Decay caused

by Rigidoporus populinus often increased the risk of stem breakage of these trees. In addition,

advanced decay caused by Phellinus igniarius and Kretzschmaria deusta were the most important

reasons for decreased safety of Acer trees.

Stovin, V. R., et al. (2008). "Street trees and stormwater management." Arboricultural J

30.

Urban trees play an important role in the urban hydrological cycle. Yet little

consideration has been given in the UK either to the increasing pressures that act to reduce urban

tree cover or the opportunities that might be provided by land-use planning policies to increase it.

Research in North America, particularly by American Forests (2007), suggests that urban tree

cover may be directly equated to stormwater volumes and, therefore, to the costs of providing

engineered structures for stormwater management. Tree planting policies have been justified on

the financial benefits associated with their stormwater management function alone,

notwithstanding the broader spectrum of benefits they provide within the urban environment.

This paper presents preliminary research aimed at transferring these findings into a UK

context. Two residential morphology units (RMUs) have been defined within the city of

Sheffield, for which current levels of tree cover have been accurately quantified. Current tree

cover levels are relatively low, but approaches to integrating more trees into these two landscape

types are outlined.

Sarr, D. A. and K. J. Puettmann (2008). "Forest management, restoration, and designer

ecosystems: Integrating strategies for a crowded planet." Ecoscience 15(1): 17-26.

As the global human population increases, the demand to conserve, restore, create, and

sustainably manage ecosystems will increase as well. Forested ecosystems are of particular

interest because of the biodiversity they support and their diverse values to people.

Developments in conservation, restoration forestry, and in the study of designer ecosystems

provide a diverse set of tools with which to pursue sustainable forestry goals. Nonetheless, we

suggest that sustainable forestry can only be achieved by fully considering ecological, economic,

and social needs in landscapes. This will require a clear realization of the trade-offs in site-

specific management approaches and a multifaceted, landscape-scale perspective for evaluation

of sustainability criteria. We propose collaborative creation of Sustainable Forestry Portfolios as

a means to encourage the breadth of thinking required to guide sustainable forest management.

We discuss 3 examples of Sustainable Forestry Portfolios with relevance to different settings in

the future: 1) the Triad Approach, 2) Forest Landscape Restoration, and 3) Urban Forestry. In all

settings, sustainable forestry is not solely a technical problem, but a challenge that must be met

through a multidimensional perspective, interdisciplinary collaboration, and with active

engagement of the people that live and work in the landscape.

Roach, W. J., et al. (2008). "Unintended consequences of urbanization for aquatic

ecosystems: A case study from the Arizona desert." BioScience 58(8): 715-727.

Many changes wrought during the construction of "designer ecosystems" arc intended to

ensure-and often succeed in ensuring-that a city call provide ecosystem goods and services; but

other changes have unintended impacts oil the ecology of the city, impairing its ability to provide

these critical functions. Indian Bend Wash, all urbanizing watershed in the Central Arizona-

Phoenix (CAP) ecosystem, provides all excellent case study of how human alteration of land

cover, streamchannel structure, and hydrology affect ecosystem processes, both intentionally and

unintentionally The construction of canals created new flowpaths that cut across historic stream

channels, and the creation of artificial lakes produced sinks for fine sediments and hotspots for

nitrogen processing. Further hydrologic manipulations, such as groundwater pumping, linked

surface flows to the aquifer and replaced ephemeral washes with perennial waters. These

alterations of hydrologic structure are typical by-products of urban growth in and and semiarid

regions and create distinct spatial and temporal patterns of nitrogen availability.

Petroff, A., et al. (2008). "Aerosol dry deposition on vegetative canopies. Part I: Review of

present knowledge." Atmos Environ 42.

This paper reviews the present knowledge of aerosol dry deposition, with respect to

modelling and experimental aspects. In the first part, special attention is given to the existing

mechanistic models, either with an analytical or a differential structure. Their predictions are

compared against available measurements for grass and forest environments, obtained under

controlled aerosol size and aerodynamic conditions. The observed differences are largely related

to the parameterisation of the aerosol collection within the canopy. In the second part, existing

experimental results are reviewed and a synthesis is provided through different inter-

comparisons concerning: (1) the influence of atmospheric stability on fine particle deposition, (2)

the evolution of coarse aerosol deposition with aerodynamic conditions and (3) the aerosol size

dependence of deposition on grass and forest canopies. A wider compilation of measurements

obtained on different canopies is finally proposed.

Peros, M. C., et al. (2008). "Continental-scale tree population response to rapid climate

change, competition and disturbance." Global Ecology and Biogeography 17(5): 658-669.

Aim Using a new approach to analyse fossil pollen data, we investigate temporal and

spatial patterns in Populus (poplar, cottonwood, aspen) from the Late Glacial to the present at

regional to continental scales. Location North America.

Methods: We extracted data on the timing and magnitude of the maximum value of

Populus pollen from each pollen diagram in the North American Pollen Database (NAPD). The

information was plotted in histograms of 150-year bins to identify times when Populus was

abundant on the landscape. We also mapped the maximum values to identify spatial patterns and

their causes.Results Our analyses show that there have been several periods since the Late

Glacial when Populus was abundant on the landscape: (1) from 12.35 to 12.65 kyr bp, in eastern

North America, largely in response to the opening of the forest following the onset of the

Younger Dryas; (2) from 10.85 to 11.75 kyr bp, following the termination of the Younger Dryas;

and (3) during the last 150 years, as land was cleared for agricultural use, especially in the

midwestern United States.Main conclusion Since the Late Glacial, changes in the abundance of

Populus were caused more by the effects of abrupt climate change on its major competitors,

rather than the direct effects of climate on Populus itself.

Nicholls, N., et al. (2008). "A simple heat alert system for Melbourne, Australia." Int J

Biometeorol 52.

A simple heat alert system, based solely on predicted maximum and minimum daily

temperatures, has been developed for the city of Melbourne in southeast Australia. The system is

based upon a demonstration that, when mean daily temperature exceeds a threshold of 30°C

(mean of today’s maximum temperature and tonight’s minimum temperature), the average daily

mortality of people aged 65 years or more is about 15–17% greater than usual. Similar numbers

of excess deaths also occur when daily minimum temperatures exceed 24°C (increases of 19–

21% over expected death rate), so a heat alert system based solely on this widely available

weather forecast variable is also feasible. No strong signal of excess heat-related deaths appears

when the data are stratified using daily maximum temperatures. This may be because in

Melbourne some days with very high maximum temperatures will be affected by the passage of

cool changes and cold fronts in the afternoon, leading to a rapid drop in temperature (i.e., some

days with high maximum temperatures will not continue to be hot throughout the day and into

the evening). A single day with temperatures exceeding the thresholds noted above is sufficient

to cause this increase in mortality, rather than requiring an extended heat wave. The increased

daily mortality does not appear to represent a short-term advancement of mortality.

Naidoo, R., et al. (2008). "Global mapping of ecosystem services and conservation

priorities." Proceedings of the National Academy of Sciences of the United States of

America 105(28): 9495-9500.

Global efforts to conserve biodiversity have the potential to deliver economic benefits to

people (i.e., "ecosystem services"). However, regions for which conservation benefits both

biodiversity and ecosystem services cannot be identified unless ecosystem services can be

quantified and valued and their areas of production mapped. Here we review the theory, data,

and analyses needed to produce such maps and find that data availability allows us to quantify

imperfect global proxies for only four ecosystem services. Using this incomplete set as an

illustration, we compare ecosystem service maps with the global distributions of conventional

targets for biodiversity conservation. Our preliminary results show that regions selected to

maximize biodiversity provide no more ecosystem services than regions chosen randomly.

Furthermore, spatial concordance among different services, and between ecosystem services and

established conservation priorities, varies widely. Despite this lack of general concordance,

"win-win" areas-regions important for both ecosystem services and biodiversity-can be usefully

identified, both among ecoregions and at finer scales within them. An ambitious interdisciplinary

research effort is needed to move beyond these preliminary and illustrative analyses to fully

assess synergies and trade-offs in conserving biodiversity and ecosystem services.

Muratet, A., et al. (2008). "Evaluation of floristic diversity in urban areas as a basis for

habitat management." Applied Vegetation Science 11(4): 451-460.

Questions: How can floristic diversity be evaluated in conservation plans to identify sites

of highest interest for biodiversity? What are the mechanisms influencing the distribution of

species in human-dominated environments? What are the best criteria to identify sites where

active urban management is most likely to enhance floristic diversity Location: The Hauts-de-

Seine district bordering Paris, France. Methods: We described the floristic diversity in one of the

most urbanized French districts through the inventory of ca. 1000 sites located in 23 habitats. We

built a new index of floristic interest (IFI), integrating information on richness, indigeneity

typicality and rarity of species, to identify sites and habitats of highest interest for conservation.

Finally, we explored the relationship between site IFI and land use patterns (LUP). Results: We

observed a total of 626 vascular plant species, Habitats with highest IFI were typically situated in

semi-natural environments or environments with moderate human impact. We also showed that

neighbouring (urban) structures had a significant influence on the floristic interest of sites: for

example. the presence of collective dwellings around a site had a strong negative impact on IFI.

Conclusions: Our approach can be used to optimize management in urban zones: we illustrate

such possibilities by defining a 'Site Potential Value'. which was then compared with the

observed IFI, to identify areas (e.g. river banks) where better management could improve the

district's biodiversity.

Mielke, H. W., et al. (2008). "Urban soil-lead (Pb) footprint: retrospective comparison of

public and private properties in New Orleans." Environmental Geochemistry and Health

30(3): 231-242.

Lead (Pb) is a toxin that after childhood exposure poses a lifetime of health risks. One

route of exposure is soil-Pb as a result of ~12 million metric tons of Pb residue in paint and

gasoline sold in the US during the 20th Century. Pb accumulated in soil of the community is a

good predictor for blood Pb of children living there. This retrospective study compares the soil-

Pb on Housing Authority of New Orleans (HANO) properties with adjacent private residential

(RES) properties within a 0.8 km (0.5 mile) radius. The sample subset (<i>n</i>=951) is from

two soil-Pb surveys (total <i>n</i>=9,493) conducted between 1989 and 2000. The properties

were in both the inner city (CORE) and outlying (OUTER) communities. The data were

analyzed using multi-response permutation procedures (MRPP). The soil-Pb results differ

significantly (<i>P</i>-value <0.001) on same-aged HANO properties at different locations;

thus, year of construction does not give adequate explanation for the soil-Pb differences. HANO

and RES soils are significantly more Pb contaminated in the CORE than in OUTER communities

(<i>P</i>-value <0.001). The CORE has many more years of traffic congestion than OUTER

communities; therefore, the lead additives to gasoline, and not lead-based paint, best elucidate

the differences of the soil-Pb footprint at HANO and RES properties in the CORE and OUTER

communities. Currently HANO properties are being redeveloped with cleaner soil, but soil on

RES properties in the CORE of New Orleans remains a large source of Pb (median=707 mg/kg

in this study) for human exposure, especially children.

Luber, G. and M. McGeehin (2008). "Climate change and extreme heat events." Am J Prev

Med 35.

The association between climate change and the frequency and intensity of extreme heat

events is now well established. General circulation models of climate change predict that

heatwaves will become more frequent and intense, especially in the higher latitudes, affecting

large metropolitan areas that are not well adapted to them. Exposure to extreme heat is already a

significant public health problem and the primary cause of weather-related mortality in the U.S.

This article reviews major epidemiologic risk factors associated with mortality from extreme

heat exposure and discusses future drivers of heat-related mortality, including a warming

climate, the urban heat island effect, and an aging population. In addition, it considers critical

areas of an effective public health response including heat response plans, the use of remote

sensing and GIS methodologies, and the importance of effective communications strategies.

Loring, P. A., et al. (2008). "The services-oriented architecture: Ecosystem services as a

framework for diagnosing change in social ecological systems." Ecosystems 11(3): 478-489.

Computational thinking (CT) is a way to solve problems and understand complex

systems that draws on concepts fundamental to computer science and is well suited to the

challenges that face researchers of complex, linked social-ecological systems. This paper

explores CT's usefulness to sustainability science through the application of the services-oriented

architecture (SOA). The SOA is a popular organizational framework in information technology

that enables businesses to describe the services they offer, including how, where, to whom, and

under what terms these services are available to consumers. It provides a straightforward,

scalable, and portable way to describe and organize complex business systems, with an emphasis

on system controls and component interactions rather than on the system components

themselves. Here, we present the SOA as a path to a more mature ecosystem services concept, in

support of integrated assessment frameworks such as the Millennium Ecosystem Assessment

(MA). With the SOA we capture important interrelationships among ecosystems, ecosystem

service consumers, and ecosystem service governance authorities, particularly the effects of their

interactions on the viability of ecosystem services. By standardizing the description and

relationships involving ecosystem services, the SOA supports a diagnostic approach for

evaluating stability and change in ecosystem service use across both space and time, when

influenced by drivers of social, political, and/or ecological change, whether directional or

stochastic, planned or otherwise. We present here a prototype of the SOA and illustrate its utility

with an example from rural Alaskan communities.

Litschke, T. and W. Kuttler (2008). "On the reduction of urban particle concentration by

vegetation - a review." Meteorol Z 17.

In order to assess the filtration performance of plants with respect to atmospheric dust,

deposition on vegeta- tion has been investigated by a number of different methods (field studies,

numerical and physical modelling) over the past few years. The intention of this review is to

assess the extent to which a reduction in particle concentration (especially PM10) can be

accomplished by existing vegetation or targeted planting on the basis of international

publications. The range of this assessment however is limited to the quantitative filtration

potential of urban vegetation. Deposition velocity was taken as a measure of filtration

performance as a parti- cle deposited on a plant is in effect taken from the atmosphere. As

regarding published deposition velocities, there are differences of an order of magnitude between

measured values and the results of model calculations. The average published value (∼1 cm s−1)

corresponds to a reduction in pollutant concentration (PM10) of about 1 % in urban areas. In

addition, analyses carried out for a busy arterial road show that very large vege- tation areas (in

excess of 10,000 m2) would be needed to compensate for local emissions of particles (PM10) by

vehicles at a deposition velocity of 1 cm s−1. However, current in-situ measurements indicate

deposition velocities considerably higher than 1 cm s−1 and, for PM1, velocities above 10 cm

s−1. If these results were confirmed by further measurements, local planting campaigns covering

small areas could also be beneficial for a reduction of particle concentrations.

Kaye, J. P., et al. (2008). "Hierarchical Bayesian scaling of soil properties across urban,

agricultural, and desert ecosystems." Ecological Applications 18(1): 132-145.

Ecologists increasingly use plot-scale data to inform research and policy related to

regional and global environmental change. For soil chemistry research, scaling from the plot to

the region is especially difficult due to high spatial variability at all scales. We used a

hierarchical Bayesian model of plot-scale soil nutrient pools to predict storage of soil organic

carbon (oC), inorganic carbon (iC), total nitrogen (N), and available phosphorus (avP) in a 7962-

km(2) area including the Phoenix, Arizona, USA, metropolitan area and its desert and

agricultural surroundings. The Bayesian approach was compared to a traditional approach that

multiplied mean values for urban mesic residential, urban xeric residential, nonresidential urban,

agricultural, and desert areas by the aerial coverage of each land-use type. Both approaches

suggest that oC, N, and avP are correlated with each other and are higher (in g/m(2)) in mesic

residential and agricultural areas than in deserts or xeric residential areas. In addition to

traditional biophysical variables, cultural variables related to impervious surface cover, tree

cover, and turfgrass cover were significant in regression models predicting the regional

distribution of soil properties. We estimate that 1140 Gg of oC have accumulated in human-

dominated soils of this region, but a significant portion of this new C has a very short mean

residence time in mesic yards and agricultural soils. For N, we estimate that 130 Gg have

accumulated in soils, which explains a significant portion of "missing N" observed in the

regional N budget. Predictions for iC differed between the approaches because the Bayesian

approach predicted iC as a function of elevation while the traditional approach employed only

land use. We suggest that Bayesian scaling enables models that are flexible enough to

accommodate the diverse factors controlling soil chemistry in desert, urban, and agricultural

ecosystems and, thus, may represent an important tool for ecological scaling that spans land-use

types. Urban planners and city managers attempting to reduce C emissions and N pollution

should consider ways that landscape choices and impervious surface cover affect city-wide soil

C, N, and P storage.

Jim, C. Y. and W. Y. Chen (2008). "Assessing the ecosystem service of air pollutant

removal by urban trees in Guangzhou (China)." Journal of Environmental Management

88(4): 665-676.

In Chinese cities, air pollution has become a serious and aggravating environmental

problem undermining the sustainability of urban ecosystems and the quality of urban life.

Besides technical solutions to abate air pollution, urban vegetation is increasingly recognized as

an alternative ameliorative method by removing some pollutants mainly through dry deposition

process. This paper assesses the capability and monetary value of this ecosystem service in

Guangzhou city in South China. The results indicated an annual removal of SO2, NO2 and total

suspended particulates at about 312.03Mg, and the benefits were valued at RMB90.19 thousand

(US$1.00 = RMB8.26). More removal was realized by recreational land use due to a higher tree

cover. Higher concentration of pollutants in the dry winter months induced more removal. The

lower cost of pollution abatement in China generated a relatively subdued monetary value of this

environmental benefit in comparison with developed countries. Younger districts with more

extensive urban trees stripped more pollutants from the air, and this capacity was anticipated to

increase further as their trees gradually reach final dimensions and establish a greater tree cover.

Tree cover and pollutant concentration constitute the main factors in pollutant removal by urban

trees. The efficiency of atmospheric cleansing by trees in congested Chinese cities could be

improved by planting more trees other than shrubs or grass, diversifying species composition and

biomass structure, and providing sound green space management. The implications for greenery

design were discussed with a view to maximizing this ecosystem service in Chinese cities and

other developing metropolises.

Jim, C. Y. and W. Y. Chen (2008). "Pattern and divergence of tree communities in Taipei's

main urban green spaces." Landscape and Urban Planning 84(3-4): 312-323.

Urban vegetation increasingly contributes to nature conservation and ecosystem services,

but lacking understanding of site variations has restricted such uses. This study analyzed the

spatial pattern and differentiation of tree communities in three major green landscape types

(urban parks, riverside parks and street verges) in Taipei city. In each landscape type, 10

representative tree communities were studied. Statistical tests for ecological communities were

employed: Jaccard and Q species similarity indices, two-way indicator species analysis

(TWINSPAN), and new species fidelity, landscape fidelity and composite Q indices. Significant

recent increase in Taipei's green spaces was traced. The study area contained 164 tree species,

but few were shared by the three landscape types and none by 30 communities. Native evergreen

broadleaf species with large final dimensions were dominant. Urban parks registered the highest

species richness, landscape fidelity, rare species and urban endemics. Such exclusive species

constitution deviated notably from riverside parks and street verges, with relatively simple and

converging intra-site species ingredients. Pronounced species differentiation between urban

parks reflected diversified site topography, natural woodland inheritance, woodland creation, and

past landscape fashion. TWINSPAN classified the communities into nine groups each with

signature characteristics. Inherent site variations offered main determinants of tree heterogeneity,

superimposed by human modification to satisfy pre-determined site functions. A hybrid urban

park with high species diversity and nature contents is advocated by amalgamating conventional

but polarized designs of country and urban parks. The findings could inform management of

urban forest, urban nature conservation, and ecological services of urban green spaces.

Jarup, L., et al. (2008). "Hypertension and exposure to noise near airports: the HYENA

study." Environ Health Perspect 116.

Background: An increasing number of people are exposed to aircraft and road traffic

noise. Hypertension is an important risk factor for cardiovascular disease, and even a small

contribution in risk from environmental factors may have a major impact on public health.

Objectives: The HYENA (Hypertension and Exposure to Noise near Airports) study

aimed to assess the relations between noise from aircraft or road traffic near airports and the risk

of hypertension.

Methods: We measured blood pressure and collected data on health, socioeconomic, and

lifestyle factors, including diet and physical activity, via questionnaire at home visits for 4,861

persons 45–70 years of age, who had lived at least 5 years near any of six major European

airports. We assessed noise exposure using detailed models with a resolution of 1 dB (5 dB for

United Kingdom road traffic noise), and a spatial resolution of 250 × 250 m for aircraft and 10 ×

10 m for road traffic noise.

Results: We found significant exposure–response relationships between night-time

aircraft as well as average daily road traffic noise exposure and risk of hypertension after

adjustment for major confounders. For night-time aircraft noise, a 10-dB increase in exposure

was associated with an odds ratio (OR) of 1.14 [95% confidence interval (CI), 1.01–1.29]. The

exposure–response relationships were similar for road traffic noise and stronger for men with an

OR of 1.54 (95% CI, 0.99–2.40) in the highest exposure category (> 65 dB; ptrend = 0.008).

Conclusions: Our results indicate excess risks of hypertension related to long-term noise

exposure, primarily for night-time aircraft noise and daily average road traffic noise.

Jackson, L. E., et al. (2008). "Roots nitrogen transformations, and ecosystem services."

Annual Review of Plant Biology 59: 341-363.

This review considers some of the mechanistic processes that involve roots in the soil

nitrogen (N) cycle, and their implications for the ecological functions that retain N within

ecosystems: 1) root signaling pathways for N transport systems, and feedback inhibition,

especially for NO3- uptake; 2) dependence on the mycorrhizal and Rhizobium/legume

symbioses and their tradeoffs for N acquisition; 3) soil factors that influence the supply of NH4+

and NO3- to roots and soil microbes; and 4) rhizosphere processes that increase N cycling and

retention, such as priming effects and interactions with the soil food web. By integrating

information on these plant-microbe-soil N processes across scales and disciplinary boundaries,

we propose ideas for better manipulating ecological functions and processes by which the

environment provides for human needs, i.e., ecosystem services. Emphasis is placed on

agricultural systems, effects of N deposition in natural ecosystems, and ecosystem responses to

elevated CO2 concentrations. This shows the need for multiscale approaches to increase human

dependence on a biologically based N supply.

Grimm, N. B., et al. (2008). "The changing landscape: ecosystem responses to urbanization

and pollution across climatic and societal gradients." Frontiers in Ecology and the

Environment 6(5): 264-272.

Urbanization, an important driver of climate change and pollution, alters both biotic and

abiotic ecosystem properties within, surrounding, and even at great distances from urban areas.

As a result, research challenges and environmental problems must be tackled at local, regional,

and global scales. Ecosystem responses to land change are complex and interacting, occurring on

all spatial and temporal scales as a consequence of connectivity of resources, energy, and

information among social, physical, and biological systems. We propose six hypotheses about

local to continental effects of urbanization and pollution, and an operational research approach to

test them. This approach focuses on analysis of "megapolitan" areas that have emerged across

North America, but also includes diverse wildland-to-urban gradients and spatially continuous

coverage of land change. Concerted and coordinated monitoring of land change and

accompanying ecosystem responses, coupled with simulation models, will permit robust

forecasts of how land change and human settlement patterns will alter ecosystem services and

resource utilization across the North American continent. This, in turn, can be applied globally.

Fornara, D. A. and D. Tilman (2008). "Plant functional composition influences rates of soil

carbon and nitrogen accumulation." Journal of Ecology 96(2): 314-322.

Summary 1. The mechanisms controlling soil carbon (C) and nitrogen (N) accumulation

are crucial for explaining why soils are major terrestrial C sinks. Such mechanisms have been

mainly addressed by imposing short-term, step-changes in CO2, temperature and N fertilization

rates on either monocultures or low-diversity plant assemblages. No studies have addressed the

long-term effects of plant functional diversity (i.e. plant functional composition) on rates of soil

C accumulation in N-limited grasslands where fixation is the main source of N for plants. 2. Here

we measure net soil C and N accumulation to 1 m soil-depth during a 12-year-long grassland

biodiversity experiment established on agriculturally degraded soils at Cedar Creek, Minnesota,

USA. 3. We show that high-diversity mixtures of perennial grassland plant species stored 500%

and 600% more soil C and N than, on average, did monoculture plots of the same species.

Moreover, the presence of C4 grasses and legumes increased soil C accumulation by 193% and

522%, respectively. Higher soil C and N accrual resulted both from increased C and N inputs via

(i) higher root biomass, and (ii) from greater root biomass accumulation to 60 cm soil depth

resulting from the presence of highly complementary functional groups (i.e. C4 grasses and

legumes). 4. Our results suggest that the joint presence of C4 grass and legume species is a key

cause of greater soil C and N accumulation in both higher and lower diversity plant assemblages.

This is because legumes have unique access to N, and C4 grasses take up and use N efficiently,

increasing below-ground biomass and thus soil C and N inputs. 5. Synthesis. We demonstrate

that plant functional complementarity is a key reason why higher plant diversity leads to greater

soil C and N accumulation on agriculturally degraded soils. We suggest the combination of key

C4 grass-legume species may greatly increase ecosystem services such as soil C accumulation

and biomass (biofuel) production in both high- and low-diversity N-limited grassland systems.

Elmendorf, W. (2008). "The importance of trees and nature in community: A review of the

relative literature." Arboriculture and Urban Forestry 34(3): 152.

A growing body of literature and experience revolves around the beneficial and

connected relationships among nature, social settings, and social processes like interaction. This

literature argues that the natural environment is a critical component of personal and community

pride and well-being and a stimulus for collaborative action. Furthermore, it argues that

empowering people to become involved in the process of landscape and park creation and

maintenance increases social interaction, builds community capacity, and supports both

development of community and community. Tree plantings and other civic environmental

projects can be used to promote both healthy environments and healthy social structure even in

the most deteriorated neighbor- hoods. As such, participatory environmental projects are strong

tools of community development, and the work of arborists and urban foresters can play an

important part in the process of community.

Deng, H. B., et al. (2008). "Current situation and development of Chinese urban forestry."

International Journal of Sustainable Development and World Ecology 15(4): 371-377.

This paper introduces Chinese urban forestry research in terms of the concept, forest

types, ecosystem services, spatial structure, planning and construction, assessment and

management. Modern Chinese urban forest had a close relationship with traditional landscape

architecture. Urban forest services had been quantified in some case cities, and determined by

urban forest spatial patterns and internal structures. Based on landscape ecology and urban

planning, urban forest spatial patterns have been analysed and planned rationally in some cities.

However, studies on urban forestry generally lack long-term, continuous and systemic

observations, as well as in-depth research on ecological processes and mechanisms. The

development trends in urban forestry in China might include extensive application of '3S'

technology, research on the relationship between urban forest landscape spatial patterns and their

ecological effects, economic assessment, ecological and economic benefits and studies on the

negative effects of pollutants.

Carter, T. and L. Fowler (2008). "Establishing Green Roof Infrastructure Through

Environmental Policy Instruments." Environmental Management 42(1): 151-164.

Traditional construction practices provide little opportunity for environmental

remediation to occur in urban areas. As concerns for environmental improvement in urban areas

become more prevalent, innovative practices which create ecosystem services and ecologically

functional land cover in cities will be in higher demand. Green roofs are a prime example of one

of these practices. The past decade has seen the North American green roof industry rapidly

expand through international green roof conferences, demonstration sites, case studies, and

scientific research. This study evaluates existing international and North American green roof

policies at the federal, municipal, and community levels. Green roof policies fall into a number

of general categories, including direct and indirect regulation, direct and indirect financial

incentives, and funding of demonstration or research projects. Advantages and disadvantages of

each category are discussed. Salient features and a list of prompting standards common to

successfully implemented green roof strategies are then distilled from these existing policies. By

combining these features with data collected from an experimental green roof site in Athens,

Georgia, the planning and regulatory framework for widespread green roof infrastructure can be

developed. The authors propose policy instruments be multi-faceted and spatially focused, and

also propose the following recommendations: (1) Identification of green roof overlay zones with

specifications for green roofs built in these zones. This spatial analysis is important for

prioritizing areas of the jurisdiction where green roofs will most efficiently function; (2) Offer

financial incentives in the form of density credits and stormwater utility fee credits to help

overcome the barriers to entry of the new technology; (3) Construct demonstration projects and

institutionalize a commitment greening roofs on publicly-owned buildings as an effective way of

establishing an educated roofing industry and experienced installers for future green roof

construction.

Campanella, B., et al. (2008). "Urban tree management in walloon municipalities: overview

of available means." Biotechnologie Agronomie Societe Et Environnement 12(3): 239-244.

A survey has been sent in 2006 to the 262 municipalities from Wallonia concerning their

green areas management and particularly focused on local arboricultural heritage. The

questionnaire was structured by 3 themes: (1) the managed heritage. (2) economical and

technical means available for municipalities, (3) available management tools. Fifty-three answers

have been gathered which represent 20.2%. This enquiry gives a first overview of the situation. It

shows that 70% of answering municipalities have no specific green service. Tree management is

a priority for only 11% of the municipal services that are involved in urban greening. Half of the

municipalities are delegating at least a part of green area management to private societies. That

concerns tree pruning, safety diagnosis, tree care and revitalisation. Only 15% of municipalities

have a complete inventory of their trees. Ninety percent declare they have no planning toot and

95% have no legal text describing good management practices. All important information and

formation work is then necessary to reinforce local tree managers to avoid that well known

mistakes Continue to be done (death of veteran trees after herbicide misuse, tree topping, root

destruction during public works. etc.).

Byrne, L. B., et al. (2008). "Ecosystem Properties of Urban Land Covers at the

Aboveground-Belowground Interface." Ecosystems 11(7): 1065-1077.

Understanding of ecological differences among urban land covers can guide the

sustainable management of urbanized landscapes for conservation of ecosystem services. The

objective of our study was to compare ecosystem properties at the aboveground-belowground

interface of three land-cover types commonly found in residential landscapes: lawns, bark mulch,

and gravel mulch. Using unmowed vegetation as a reference land cover, we measured surface

soil variables (to 5 cm depth), CO2 fluxes, and ground temperatures in experimental field plots

within 3 years after their creation. Each land cover had a distinctive set of ecosystem properties.

Mulched plots had significantly warmer soil and surface temperatures, wetter soils and faster

surface litter decomposition than vegetated plots. Variables associated with soil C and

earthworm numbers were consistently lowest in gravel-covered soils, whereas bark mulch plots

had highest earthworm abundances, lowest soil bulk density, and temporally variable soil organic

matter dynamics. Compared to unmowed plots, lawns had higher soil carbon, CO2 fluxes, and

temperatures but lower earthworm abundances especially during 2005 drought conditions. We

conclude that ecosystem properties of the land covers were influenced by the composition,

density, and arrangement of materials comprising their aboveground habitat structures. We

discuss our results within an ecosystem services framework and suggest that interpretations of

our findings depend on in situ urban environmental contexts and landscape management

objectives. Future studies of urban land covers, their ecosystem properties and associated

ecosystem services are needed to help provide a scientific basis for sustainable urban landscape

management.

Burley, S., et al. (2008). "Post-hurricane vegetation recovery in an urban forest."

Landscape and Urban Planning 85(2): 111-122.

Urban forests are increasingly vulnerable to catastrophic disturbance, and their isolation

and human use may challenge the ability of vegetation to recover spontaneously. We examined

vegetation responses to recent hurricane disturbance in a temperate mixedwood urban forest:

Point Pleasant Park in Halifax, Nova Scotia, which suffered over 70% canopy loss during

Hurricane Juan in fall 2003. In 2005 we surveyed 30 paired plots with disturbed and intact tree

canopies to assess early regeneration patterns and seed banks. Native early successional tree

species dominated seed bank and seedling layers. Soil properties were similar between intact and

disturbed urban plots and local reference forests, thus long-term woody debris removal,

hurricane disturbance and subsequent clean-up activities have not caused substantial soil

degradation. Non-native species were not abundant throughout the park but were concentrated at

the park boundary adjacent to residential neighbourhoods. The results of this study suggest that

urban forests can show natural successional trajectories after catastrophic disturbance, and

management is probably not necessary for forest recovery in Point Pleasant Park. Conversely,

intervention to speed up regeneration of shade-tolerant canopy species may be desired by local

citizens, so managers will have to balance conflicting values in developing a restoration plan for

the park.

Bonan, G. B. (2008). "Forests and climate change: Forcings, feedbacks, and the climate

benefits of forests." Science 320(5882): 1444-1449.

The world's forests influence climate through physical, chemical, and biological

processes that affect planetary energetics, the hydrologic cycle, and atmospheric composition.

These complex and nonlinear forest-atmosphere interactions can dampen or amplify

anthropogenic climate change. Tropical, temperate, and boreal reforestation and afforestation

attenuate global warming through carbon sequestration. Biogeophysical feedbacks can enhance

or diminish this negative climate forcing. Tropical forests mitigate warming through evaporative

cooling, but the low albedo of boreal forests is a positive climate forcing. The evaporative effect

of temperate forests is unclear. The net climate forcing from these and other processes is not

known. Forests are under tremendous pressure from global change. Interdisciplinary science that

integrates knowledge of the many interacting climate services of forests with the impacts of

global change is necessary to identify and understand as yet unexplored feedbacks in the Earth

system and the potential of forests to mitigate climate change.

Beier, C. M., et al. (2008). "Ecosystem services and emergent vulnerability in managed

ecosystems: A geospatial decision-support tool." Ecosystems 11(6): 923-938.

Managed ecosystems experience vulnerabilities when ecological resilience declines and

key flows of ecosystem services become depleted or lost. Drivers of vulnerability often include

local management actions in conjunction with other external, larger-scale factors. To translate

these concepts to management applications, we developed a conceptual model of feedbacks

linking the provision of ecosystem services, their use by society, and anthropogenic change.

From this model we derived a method to integrate existing geodata at relevant scales and in

locally meaningful ways to provide decision-support for adaptive management efforts. To

demonstrate our approach, we conducted a case study assessment of southeast Alaska, where

managers are concerned with sustaining fish and wildlife resources in areas where intensive

logging disturbance has occurred. Individual datasets were measured as indicators of one of three

criteria: ecological capacity to support fish/wildlife populations (provision); human acquisition

of fish/wildlife resources (use); and intensity of logging and related land-use change

(disturbance). Relationships among these processes were analyzed using two methods-a

watershed approach and a high-resolution raster-to identify where provision, use and disturbance

were spatially coupled across the landscape. Our results identified very small focal areas of

social-ecological coupling that, based on post-logging dynamics and other converging drivers of

change, may indicate vulnerability resulting from depletion of ecosystem services. We envision

our approach can be used to narrow down where adaptive management might be most beneficial,

allowing practitioners with limited funds to prioritize efforts needed to address uncertainty and

mitigate vulnerability in managed ecosystems.

Zhang, G., et al. (2007). "Urban soil environment issues and research progresses." Acta

Pedologica Sinica 44(5): 925-933.

Urban soils act functionally as an ecological screen in protecting urban environment.

Their degradation, however, is in essence a process of providing ecological services, such as sink

of all kinds of pollutants, at the cost of their own quality. Therefore, as a result, they often come

across a variety of environmental problems. Besides physical degradation, such as compaction,

enrichment of various elements associated with human activities, heavy metals, and organic

pollution are the major problems with urban soil environment. The main features of urban soil

contamination are characterized firstly by strong accumulation of so-called 'urban elements' such

as Cu, Zn, Pb and Hg, but less of other heavy metals; and secondly by spatial isolation, which

means the contamination is not spatially continuous. During the process of urban development,

heavy metal contamination of urban soils happens not only nowadays, but also did in the past,

especially when primitive mining and metal processing prevailed. Furthermore, urban soils are

often polluted by organic pollutants, especially polycyclic aromatic hydrocarbons (PAHs), with

roadsides and industrial sites being the major vulnerable areas. PAHs therein have normally 2-6

rings and predominantly 2-4 rings, strongly suggesting their pyrogenic background, including

motor vehicles, industrial activities and coal burning.

Xiao, Q., et al. (2007). "Hydrologic processes at the urban residential scale." Hydrological

Processes 21(16): 2174-2188.

In the face of increasing urbanization, there is growing interest in application of

microscale hydrologic solutions to minimize storm runoff and conserve water at the source. In

this study, a physically based numerical model was developed to understand hydrologic

processes better at the urban residential scale and the interaction of these processes among

different best management practices (BMPs). This model simulates hydrologic processes using

an hourly interval for over a full year or for specific storm events. The model was applied to

treatment and control single-family residential parcels in Los Angeles, California. Data collected

from the control and treatment sites over 2 years were used to calibrate and validate the model.

Annual storm runoff to the street was eliminated by 97% with installation of rain gutters, a

driveway interceptor, and lawn retention basin. Evaluated individually, the driveway interceptor

was the most effective BMP for storm runoff reduction (65%), followed by the rain gutter

installation (28%), and lawn converted to retention basin (12%). An 11 m(3) cistern did not

substantially reduce runoff, but provided 9% of annual landscape irrigation demand. Simulated

landscape irrigation water use was reduced 53% by increasing irrigation system efficiency, and

adjusting application rates monthly based on plant water demand. The model showed that

infiltration and surface runoff processes were particularly sensitive to the soil's physical

properties and its effective depth. Replacing the existing loam soil with clay soil increased

annual runoff discharge to the street by 63% when climate and landscape features remained

unchanged.

van Roon, M. (2007). "Water localisation and reclamation: Steps towards low impact

urban design and development." Journal of Environmental Management 83(4): 437-447.

Numerous drivers are providing stimulus for increased water cycle localisation within

urban neighbourhoods. This paper uses predominantly Australasian case studies to highlight

trends, successes and challenges in the transition to neighbourhood centred water-based services

using 'Low Impact' and 'Water Sensitive' design and development techniques. Major steps

towards urban sustainability are demonstrated, for example, up to 70% reduction in the demand

for potable water (Aurora, Melbourne), removal of contaminated stormwater and sewage effluent

discharge to natural waterways vulnerable to nutrient or toxin accumulation, and up to 55% of

the area of the greenfield site planted in indigenous species (Regis Park, New Zealand). Reduced

demand for potable water would enable continued undiluted use of 'pure' water sources from

limited bush catchments (Waitakere Ranges, New Zealand), and less dependence on rivers

stressed by low flows. Reductions and dispersion of sewage effluent discharges protects

receiving waters, such as Port Phillip Bay, Melbourne, from eutrophication. Reduced stormwater

discharge favours retention of the natural hydrological regime of rivers and minimises

bioaccumulation of toxins in aquatic ecosystems.

Troy, A. R., et al. (2007). "Predicting opportunities for greening and patterns of vegetation

on private urban lands." Environmental Management 40(3): 394-412.

This paper examines predictors of vegetative cover on private lands in Baltimore,

Maryland. Using high-resolution spatial data, we generated two measures: "possible

stewardship," which is the proportion of private land that does not have built structures on it and

hence has the possibility of supporting vegetation, and "realized stewardship," which is the

proportion of possible stewardship land upon which vegetation is growing. These measures were

calculated at the parcel level and averaged by US Census block group. Realized stewardship was

further defined by proportion of tree canopy and grass. Expenditures on yard supplies and

services, available by block group, were used to help understand where vegetation condition

appears to be the result of current activity, past legacies, or abandonment. PRIZM (TM) market

segmentation data were tested as categorical predictors of possible and realized stewardship and

yard expenditures. PRIZM (TM) segmentations are hierarchically clustered into 5, 15, and 62

categories, which correspond to population density, social stratification (income and education),

and lifestyle clusters, respectively. We found that PRIZM 15 best predicted variation in possible

stewardship and PRIZM 62 best predicted variation in realized stewardship. These results were

further analyzed by regressing each dependent variable against a set of continuous variables

reflective of each of the three PRIZM groupings. Housing age, vacancy, and population density

were found to be critical determinants of both stewardship metrics. A number of lifestyle factors,

such as average family size, marriage rates, and percentage of single-family detached homes,

were strongly related to realized stewardship. The percentage of African Americans by block

group was positively related to realized stewardship but negatively related to yard expenditures.

Tratalos, J., et al. (2007). "Urban form, biodiversity potential and ecosystem services."

Landscape and Urban Planning 83(4): 308-317.

Using data from selected areas in five UK cities, we studied the relationships between

urban form and the following measures of ecosystem performance: availability and patch

characteristics of tree cover, gardens and green space; storm-water run-off; maximum

temperature; carbon sequestration. Although most measures of ecosystem performance declined

with increasing urban density, there was considerable variability in the relationships. This

suggests that at any given density, there is substantial scope for maximising ecological

performance. The social status of residents was related to measures of tree cover. Housing type

was significantly associated with some types of ecosystem service provision, indicating that the

type of development may be important independent of its density. These findings have

implications for understanding the distribution of ecosystem services and biodiversity across

urban landscapes, and the management of development aimed at meeting UK government

housing density targets.

Takebayashi, H. and M. Moriyama (2007). "Surface heat budget on green roof and high

reflection roof for mitigation of urban heat island." Building and Environment 42(8): 2971-

2979.

In this study, the surface temperature, net radiation, water content ratio, etc., of green

roofs and high reflection roofs are observed. The heat and water budget are compared to each

other. In the daytime, the temperature of the cement concrete surface, the surface with highly

reflective gray paint, bare soil surface, green surface and the surface with highly reflective white

paint are observed to be in descending order. On a surface with highly reflective white paint, the

sensible heat flux is small because of the low net radiation due to high solar reflectance. On the

green surface, the sensible heat flux is small because of the large latent heat flux by evaporation,

although the net radiation is large. On the cement concrete surface and the surface with a highly

reflective gray paint, the sensible heat fluxes have almost the same values because their solar

reflectance is approximately equal. These tendencies of the sensible heat flux accord with the

pitch relation of the surface temperature. Methods to estimate the quantity of evaporation,

evaporative efficiency, heat conductivity, and thermal capacity are explained, and the

observation data is applied to these methods.

Pataki, D. E., et al. (2007). "Inferring biogenic and anthropogenic carbon dioxide sources

across an urban to rural gradient." Oecologia 152(2): 307-322.

We continuously monitored CO2 concentrations at three locations along an urban-to-rural

gradient in the Salt Lake Valley, Utah from 2004 to 2006. The results showed a range of CO2

concentrations from daily averages exceeding 500 p.p.m. at the city center to much lower

concentrations in a non-urbanized, rural region of the valley. The highest values were measured

in the wintertime and under stable atmospheric conditions. At all three sites, we utilized weekly

measurements of the C and O isotope composition of CO2 for a 1-year period to evaluate the

CO2 sources underlying spatial and temporal variability in CO2 concentrations. The results of an

inverse analysis of CO2 sources and the O isotope composition of ecosystem respiration (delta

O-18(R)) showed large contributions (> 50%) of natural gas combustion to atmospheric CO2 in

the wintertime, particularly at the city center, and large contributions (> 60%) of biogenic

respiration to atmospheric CO2 during the growing season, particularly at the rural site. delta O-

18(R) was most enriched at the rural site and more isotopically depleted at the urban sites due to

the effects of irrigation on ecosystem water pools at the urban sites. The results also suggested

differences in the role of leaf versus soil respiration between the two urban sites, with seasonal

variation in the contribution of leaf respiration at a residential site and relatively constant

contributions of leaf respiration at the city center. These results illustrate that spatial and

temporal patterns of urban CO2 concentrations and isotopic composition can be used to infer

patterns of energy use by urban residents as well as plant and soil processes in urban areas.

Oleksyn, J., et al. (2007). "Ecophysiology of horse chestnut (Aesculus hippocastanum L.) in

degraded and restored urban sites." Polish Journal of Ecology 55(2): 245-260.

We explored changes in growth, phenology, net CO2 assimilation rate, water use

efficiency, secondary defense compounds, substrate and foliage nutrient concentration of a

degraded urban horse chestnut (Aesculus hippocastanum L.) site restored for three years using

mulching (tree branches including foliage) and fertilization (primarily nitrogen addition). Prior to

restoration, this site was characterized by high pH (ca. 8), low foliage and substrate N, and high

Na and Cl concentration. Our data indicated that in untreated plots NaCl used for road deicing is

the decisive factors that may be responsible for the decrease of foliar N concentration (via a

reduction in NO3- uptake), for the decrease in photosynthesis (through high concentrations of Na

and Cl in the leaves) and for increased senescence of the leaves. After three years of treatment,

total nitrogen concentration in substrate increased by 3- to 4-fold and calcium concentration

decreased by more than 50% in relation to pretreatment levels. Treatment significantly increased

seed production (from less than 12 to more than 100 seeds per tree), individual leaf mass (from

1.8 to 3.3 g/leaf), CO2 assimilation rate (by 21 to 30%), improved leaf C:N ratio, and increased

foliage life span by as much as six weeks. The beginning of leaf fall in untreated control trees

started in mid-July and those of mulched and fertilized trees in late October. Applied treatment

also eliminated visible symptoms of leaf damage due to high sodium and chlorine levels,

indicating the possible role of other factors in the development of necroses. After three years of

treatment, pH of most degraded plots declined from 8.2 to 7.8. That decline was accompanied by

an increase in foliar Zn, Cu, and Pb concentration in the mulched and fertilized plants. In

addition, treatment lowered foliage phenolics making these plants potentially more vulnerable to

insect herbivory. Our study indicates that stable carbon isotope discrimination is of little value as

an indicator of cumulative salinity and urban environment stress in A. hippocastanum due to

pronounced differences in leaf phenology and ontogeny. The results of our study show that street

tree recovery can take as little as two to three years after application of fertilization and

mulching.

Liu, Y.-J., et al. (2007). "Which ornamental plant species effectively remove benzene from

indoor air?" Atmospheric Environment 41(3): 650-654.

Phytoremediation—using plants to remove toxins—is an attractive and cost effective way

to improve indoor air quality. This study screened ornamental plants for their ability to remove

volatile organic compounds from air by fumigating 73 plant species with 150 ppb benzene, an

important indoor air pollutant that poses a risk to human health. The 10 species found to be most

effective at removing benzene from air were fumigated for two more days (8 h per day) to

quantify their benzene removal capacity. Crassula portulacea, Hydrangea macrophylla,

Cymbidium Golden Elf., Ficus microcarpa var. fuyuensis, Dendranthema morifolium, Citrus

medica var. sarcodactylis, Dieffenbachia amoena cv. Tropic Snow; Spathiphyllum Supreme;

Nephrolepis exaltata cv. Bostoniensis; Dracaena deremensis cv. Variegata emerged as the

species with the greatest capacity to remove benzene from indoor air.

Lehvävirta, S. (2007). "Non-anthropogenic dynamic factors and regeneration of

(hemi)boreal urban woodlands - synthesising urban and rural ecological knowledge."

Urban Forestry & Urban Greening 6(3): 119-134.

The natural dynamics of urban woodlands are seldom discussed despite the general

acknowledgement that understanding of natural processes is a prerequisite for successful

management of ecosystems. This paper reviews the non-anthropogenic dynamic factors, and

anthropogenic changes in them, in urban woodlands. Several gaps in the knowledge are

identified: (1) amount of tree regeneration and factors affecting it, (2) seedbed availability for

poor competitors, (3) wind as a dynamic factor, (4) insect outbreak severity, (5) effect of urban

climate on tree regeneration, (6) pollination and dispersal and (7) effect of herbivory on tree

regeneration. It is concluded that natural dynamics drive regeneration in urban woodlands, but

the disturbance regime and successional pathways may be altered. Natural colonisation of

derelict land and natural dynamics in existing woodlands are beneficial because of decreased

management costs, and the biodiversity, educational, recreational and psychological values they

provide.

Lal, R. (2007). "Soil science and the carbon civilization." Soil Science Society of America

Journal 71(5): 1425-1437.

Soil science must play a crucial role in meeting present and emerging societal needs of

the 21st century and beyond for a population expected to stabilize around 10 billion and having

increased aspirations for a healthy diet and a rise in the standards of living. In addition to

advancing food security by eliminating hunger and malnutrition, soil resources must be managed

regarding numerous other global needs through interdisciplinary collaborations. Some of which

are to mitigate global warming; to improve quantity and quality of freshwater resources; to

enhance biodiversity; to minimize desertification; serve as a repository of Waste; air archive of

human and planetary history; meet growing energy demands; develop strategies of sustainable

management of urban ecosystems; alleviate poverty of agricultural communities as an engine of

economic development; and fulfill aspirations of rapidly urbanizing and industrializing societies.

In addition to food and ecosystem services, bio-industries (e.g., plastics, solvents, paints,

adhesives, pharmaceuticals and chemicals) through plant-based compounds (carbohydrates,

proteins, and oils) and energy plantations (bioethanol and biodiesel) can revolutionize

agriculture. These diverse and complex demands on soil resources necessitate a shift in strategic

thinking and conceptualizing sustainable management of soil resources in agroecosystems to

provide A ecosystem services while also meeting the needs for food, feed, fiber, and fuel by

developing multifunctional production systems. There is a strong need to broaden the scope of

soil science to effectively address ever changing societal needs. To do this, soil scientists must

rally with allied sciences including hydrology, climatology, geology, ecology, biology, physical

sciences (chemistry, physics), and engineering. Use of nanotechnology, biotechnology, and

information technology can play an important role in addressing emerging global issues. Pursuit

of sustainability, being a moral/ethical and political challenge, must be addressed in cooperation

with economists and political scientists. Soil scientists must work in cooperation with industrial

ecologists and urban planners toward sustainable development and management of soils in urban

and industrial ecosystems. More than half of the world's population (3.3 billion) live in towns

and cities, and the number of urban dwellers is expected to increase to 5 billion by 2030. Thus,

the study of urban soils for industrial use, human habitation, recreation, infrastructure forestry,

and urban agriculture is a high priority. Soil scientists Must nurture symbiotic/synergistic

relations with numerous stake holders including land managers, energy companies and carbon

traders, urban planners, waste disposal organizations, and conservators of natural resources.

Trading of C credits in a trillion-dollar market by 2020 must be made accessible to land

managers, especially the resource-poor farmers in developing countries. Soil science curricula, at

undergraduate and graduate levels, Must be revisited to provide the needed background in all

basic and applied sciences with focus on globalization. We must raise the profile of soil science

profession and position Students in the competitive world of ever flattening Earth.

Konijnendijk, C. C., et al. (2007). "Decision-support for land-use planning through

valuation of urban forest benefits." Allgemeine Forst Und Jagdzeitung 178(4): 74-84.

Many environmental and social services provided by urban and peri-urban forests are

difficult to assess and quantify, for example, in monetary terms. This weakens the position of

urban forestry in urban development and land use planning discussions. Therefore, there is a

need to develop assessment approaches that can strengthen the policy-science interface by acting

as decision-support tools within wider urban and regional policy-making contexts. Examples are

presented where different methods for assessing social and environmental values of existing and

new urban woodland were applied. These include an economic valuation study applying hedonic

pricing assessing the effect of peri-urban afforestation on house prices in Denmark. Social

valuation through social value mapping was studied in Helsinki, Finland. Finally, in Malaysia,

various tools were combined to assess the multiple costs and benefits association with preserving

one of the last remaining original forest areas near Kuala Lumpur. The different assessment tools

have their respective strengths and weaknesses from a decision-support perspective, and for use

under different circumstances. Combining different urban forest valuation tools is the preferred

option in land-use planning.

Irwin, E. G. and N. E. Bockstael (2007). "The evolution of urban sprawl: Evidence of

spatial heterogeneity and increasing land fragmentation." Proceedings of the National

Academy of Sciences of the United States of America 104(52): 20672-20677.

We investigate the dynamics and spatial distribution of land use fragmentation in a

rapidly urbanizing region of the United States to test key propositions regarding the evolution of

sprawl. Using selected pattern metrics and data from 1973 and 2000 for the state of Maryland,

we find significant increases in developed and undeveloped land fragmentation but substantial

spatial heterogeneity as well. Estimated fragmentation gradients that describe mean

fragmentation as a function of distance from urban centers confirm the hypotheses that

fragmentation rises and falls with distance and that the point of maximum fragmentation shifted

outward over time. However, rather than outward increases in sprawl balanced by development

infill, we find substantial and significant increases in mean fragmentation values along the entire

urban-rural gradient. These findings are in contrast to the results of Burchfield et al. [Burchfield

M, Overman HG, Puga D, Turner MA (2006) Q J Econ 121:587-633], who conclude that the

extent of sprawl remained roughly unchanged in the Unites States between 1976 and 1992. As

demonstrated here, both the data and pattern measure used in their study are systematically

biased against recording low-density residential development, the very land use that we find is

most strongly associated with fragmentation. Other results demonstrate the association between

exurban growth and increasing fragmentation and the systematic variation of fragmentation with

nonurban factors. In particular, proximity to the Chesapeake Bay is negatively associated with

fragmentation, suggesting that an attraction effect associated with this natural amenity has

concentrated development.

Hodges, A. W. and J. J. Haydu (2007). "Growth and challenges in Florida's environmental

horticulture industry." HortTechnology 17(3): 371-378.

Total Florida environmental horticulture industry sales in 2005 were $15.24 billion (B),

whereas total industry output amounted to $10.39 B with $3.01 B for wholesale nurseries, $5.25

B for landscape services, and $2.13 B for horticultural retailers, which reflects the average gross

margin on retail sales. Direct employment in the industry was 190,000 full-time jobs plus nearly

104,000 temporary, part-time, or seasonal jobs. Total employment impacts were 319,000 full-

time and part-time/seasonal jobs, including 24,000 jobs created in other sectors of the economy.

Total value-added or income impacts of $8.65 B included $5.19 B in labor income for employee

wages, salaries, and business owner (proprietor) income. Fiscal impacts included $549 million

(M) in indirect business taxes paid to local and state governments. Results for 2005 compared

with previous studies performed for 1997 and 2000 indicate that growth in the industry has been

dramatic over this time period. Industry sales increased from $8.35 B in 1997 to $15.24 B in

2005, representing a 7.8% average annual compound growth rate, whereas employment impacts

grew at a 9.2% annual rate, and value-added impacts grew by 4.7%. The study also evaluated the

impacts to the industry from eight hurricanes that struck Florida during 2004 and 2005. Nearly

80% of surveyed firms were adversely impacted by at least one hurricane. Total damages and

losses resulting from hurricanes were estimated at $2.12 B, including product (crop) losses of

$1.05 B, structural damages of $465 M, and cleanup costs of $605 M. Product losses of at least

$100,000 were sustained by 22% of firms, whereas structural damages and cleanup costs of this

level were suffered by 12% and 8% of firms, respectively. Nearly half (48%) of the firms had

their business interrupted for 3 weeks or more. Despite these large losses, the industry continues

to thrive.

Godefroid, S., et al. (2007). "The role of soil and microclimatic variables in the distribution

patterns of urban wasteland flora in Brussels, Belgium." Landscape and Urban Planning

80(1-2): 45-55.

Despite increased recognition of the importance of urban vegetation research, few

attempts have been made to assess the relative influence of ecological variables on the species

composition of urban wastelands. The main aim of this paper is to assess the relative importance

of soil and microclimatic variables in structuring plant species richness and diversity in this

habitat. Field investigations were carried out in 22 wasteland sites situated within the city of

Brussels. The vegetation has been recorded in 38 4 m(2)-plots according to the Braun-Blanquet-

method. A total of 19 environmental variables were taken into consideration, among others the

presence of different kinds of anthropogenic substrates and microclimatic variables. Results

indicate that plant species composition in urban wastelands is mainly driven by soil nutrient

content, soil moisture, soil pH and light intensity (as inferred by the mean Ellenberg's indicator

values). Various types of anthropogenic substrates such as concrete, pebbles, sand and rubble

had different effects on the species composition, the proportion of neophytes, hemeroby and

urbanity level. Air temperature and humidity did show a significant influence on the presence of

some species. The contribution of these environmental variables to the species composition and

diversity of urban wastelands is discussed. (c) 2006 Elsevier B.V. All rights reserved.

Godefroid, S. and N. Koedam (2007). "Urban plant species patterns are highly driven by

density and function of built-up areas." Landscape Ecology 22(8): 1227-1239.

This paper aims to assess the relative importance of the type of built-up area in

structuring plant species composition and richness in urbanised environments. The study was

carried out in the city of Brussels where all vascular plant species were recorded in 189 grid cells

of 1 km(2) each. The effect of urban land use type on species composition was investigated using

first Canonical Correspondence Analysis. Densely built-up area was the most powerful predictor

for species composition, followed by industrial built-up areas, half open or open built-up areas

with plantations, and open built-up areas with much natural vegetation in the surroundings.

Indicator species were found for each type of built-up area and a response curve to the amount of

built land was produced using Generalised Additive Modelling. Various types of built-up areas

had different effects on environmental conditions as inferred by Ellenberg's indicator values, as

well as on the species richness, species rarity, number of exotic species and proportion of

extinction-prone species. It is concluded that future ecological studies should not treat urban

areas as homogeneous areas by combining all anthropogenic factors into one aggregated

variable. Instead, the urban matrix should be categorised in subsystems as it is multidimensional

and highly variable across space.

Gill, S. E., et al. (2007). "Adapting cities for climate change: the role of the green

infrastructure." Built Environ 33.

The urban environment has distinctive biophysical features in relation to surrounding

rural areas. These include an altered energy exchange creating an urban heat island, and changes

to hydrology such as increased surface runoff of rainwater. Such changes are, in part, a result of

the altered surface cover of the urban area. For example less vegetated surfaces lead to a

decrease in evaporative cooling, whilst an increase in surface sealing results in increased surface

runoff. Climate change will amplify these distinctive features. This paper explores the important

role that the green infrastructure, i.e. the greenspace network, of a city can play in adapting for

climate change. It uses the conurbation of Greater Manchester as a case study site. The paper

presents output from energy exchange and hydrological models showing surface temperature and

surface runoff in relation to the green infrastructure under current and future climate scenarios.

The implications for an adaptation strategy to climate change in the urban environment are

discussed.

Endlicher, W., et al. (2007). "Urban ecology—Definitions and concepts." Shrinking Cities:

Effects on Urban Ecology and Challenges on Urban Development: 1-13.

Earth’s population more than doubled during the second half of the twentieth century:

from approximately 2.5 billion in 1950 to over 6 billion in 2000, and at the time of writing in

2007 has reached a gure of over 6.6 billion. Alongside this exponential growth of population is

another important demographic trend: Ac- cording to the United Nations, the anticipated

population growth between 2000 and 2030, approximately 2 billion people, will be concentrated

in urban areas (UN 2004). The 21st century will be the century of urbanisation. By the year 2030

more than 60 per cent (4.9 billion) of the estimated world population (8.1 billion) will live in

urban settlements, compared to 29 per cent in 1950. The 50 per cent mark is expected to be

reached in the year 2007. In 2025, more than a dozen urban agglomerations will have over 20

million inhabitants, and some will have over 30 million. 23 of the 25 biggest urban

agglomerations on the planet will be in Africa, Asia, and Latin America, rather than in Europe or

North America (kRaaS 2003). These megacities are considered ‘hotspots’ of global change

(kRaaS 2007). Urbanised areas cover between approximately one and six per cent of Earth’s

surface, yet they have extraordinarily large ecological ‘footprints’ and complex, powerful, and

often indirect effects on ecosystems (ReeS & WackeRnagel 1994).

Egoh, B., et al. (2007). "Integrating ecosystem services into conservation assessments: A

review." Ecological Economics 63(4): 714-721.

A call has been made for conservation planners to include ecosystem services into their

assessments of conservation priority areas. The need to develop an integrated approach to

meeting different conservation objectives and a shift in focus towards human wellbeing are some

of the motivations behind this call. There is currently no widely accepted approach to planning

for ecosystem services. This study contributes towards the development of this approach through

a review of conservation assessments and the extent to which they include ecosystem services.

Of the 476 conservation assessments identified by a set of search terms on the Web of Science,

100 were randomly selected for this review. Of these only seven had included ecosystem

services, while another 13 had referred to ecosystem services as a rationale for conservation

without including them in the assessment. The majority of assessments were based on

biodiversity pattern data while 19 used data on ecological processes. A total of 11 of these 19

assessments used processes, which could be linked to services. Ecosystem services have

witnessed an increase in attention received in conservation assessments since the year 2000,

however trends were not apparent beyond this date. In order to assess which types of ecosystem

services and how they have been accounted for in conservation assessments, we extended our

review to include an additional nine conservation assessments which included ecosystem

services. The majority included cultural ecosystem services, followed by regulatory,

provisioning and supporting services respectively. We conclude with an analysis of the

constraints and opportunities for the integration of ecosystem services into conservation

assessments and highlight the urgent need for an appropriate framework for planning for

ecosystem services.

Crossman, N. D., et al. (2007). "Systematic landscape restoration in the rural-urban fringe:

meeting conservation planning and policy goals." Biodiversity and Conservation 16: 3781-

3802.

Many landscapes that straddle the rural/urban divide suffer from low levels of species

diversity following extensive clearing and fragmentation of native vegetation communities and

conversion of land to agriculture. Further pressures are placed on remnant vegetation by

encroaching urban expansion. These landscapes now exhibit a mosaic of small, patchy

vegetation remnants that are under considerable pressure from housing and light-industrial

development. Furthermore, agriculture in these landscapes tends to be of high economic value

from uses such as intensive horticulture. Concerted and well-planned efforts are needed to

balance the many conflicts of interest and competing demands for land with the need to restore

landscapes for the protection of biodiversity. There has been a recent move in Australia toward

regional biodiversity planning and goal setting, however specific detail on how to plan for

achieving targets in complex landscapes is lacking. This paper applies a systematic landscape

restoration model to a mixed-use, peri-urban landscape on the northern fringes of Adelaide,

South Australia. The region contains fragments of remnant vegetation amongst a mosaic of high-

value horticulture, light industry and urban development. Models produce maximally efficient

solutions that meet comprehensive, adequate and representative conservation targets. Further

constraints are added to the model to take into account the value of agricultural output, the

biodiversity value of remnants, and property size and tenure. The effects on solution efficiencies

as the number of constraints increase are investigated. This paper demonstrates the flexibility

found in applying a systematic landscape restoration methodology. The process we present can

be transferred to any rural-urban fringe region.

Ali-Toudert, F. and H. Mayer (2007). "Effects of asymmetry, galleries, overhanging

facades and vegetation on thermal comfort in urban street canyons." Solar Energy 81.

The present paper deals with the dependence of outdoor thermal comfort on the design of

an urban street. The effects of the street vertical profile, including asymmetrical canyon shapes,

the use of galleries and further shading devices on the façades, arranged in various orientations

are assessed. The study is conducted by means of numerical modelling by using the three-

dimensional microclimate model ENVI-met 3.0 which prognosticates the microclimatic changes

within urban environments. Thermal comfort is evaluated for the daytime hours across the

canyon in high spatial resolution and by means of the physiologically equivalent temperature

PET.

The results revealed that all design aspects investigated have a moderate impact on the air

temperature and a strong effect on the heat gained by a human body and hence on the resulting

thermal sensation. The larger the openness to the sky of the canyon, the higher the heat stress.

For canyons with a smaller sky view, the orientation is also decisive: E–W canyons are the most

stressful and deviating from this orientation ameliorates the thermal conditions. Basically,

galleries and further shading through overhanging façades or vegetation enable a sensitive

decrease of the period of time and of the area of thermal discomfort. Yet, this efficiency varies

with the orientation and the vertical proportions of the canyon. Therefore, if appropriately

combined, all investigated design elements can effectively mitigate heat stress in the summer and

promote thermal comfort.

Yasuda, M. and F. Koike (2006). "Do golf courses provide a refuge for flora and fauna in

Japanese urban landscapes?" Landscape and Urban Planning 75(1-2): 58-68.

Golf courses have historically been seen as places of heavy pesticide and fertilizer use,

however, there are few scientific studies on the ecology of golf courses. The aim of this study

was to assess the value of golf courses for conserving forest biota in urban landscapes. The biota

occurring in 12 Japanese golf courses and their surrounding areas was investigated.

Investigations were done at golf course sites located on the green, fairway, rough, green belts

between holes, and the out of bounds forest. Roadside, paddy fields, park and forest sites were

investigated outside the golf courses. Presence/absence data for plants, arthropods and

vertebrates in each sample habitat were analysed by TWINSPAN. As a result, communities in

golf courses were classified by the part of course (e.g. green, fairway), and not by the location of

the course nor chemical use. However, differences between golf courses in urban and rural

landscapes were detected in the biota of the whole course. The out of bounds forest of golf

courses was similar to forests that exist outside the courses, and this area held more flora and

fauna than turf vegetation and artificial biotopes outside the course such as roadside and paddy.

This suggests that golf courses in urbanised areas can be a refuge for flora and fauna, since forest

cover occurs in only limited proportions in urban landscapes. Furthermore, the application of

regulations for golf course construction seemed to be useful in maintaining forest species on golf

courses. This may contribute to the conservation of native forest biota within Japanese urban

landscapes.

Xian, G. and M. Crane (2006). "An analysis of urban thermal characteristics and

associated land cover in Tampa Bay and Las Vegas using Landsat satellite data." Remote

Sensing of Environment 104(2): 147-156.

Remote sensing data from both Landsat 5 and Landsat 7 systems were utilized to assess

urban area thermal characteristics in Tampa Bay watershed of west-central Florida, and the Las

Vegas valley of southern Nevada. To quantitatively determine urban land use extents and

development densities, sub-pixel impervious surface areas were mapped for both areas. The

urban-rural boundaries and urban development densities were defined by selecting certain

imperviousness threshold values and Landsat thermal bands were used to investigate urban

surface thermal patterns. Analysis results suggest that urban surface thermal characteristics and

patterns can be identified through qualitatively based urban land use and development density

data. Results show the urban area of the Tampa Bay watershed has a daytime heating effect

(heat-source), whereas the urban surface in Las Vegas has a daytime cooling effect (heat-sink).

These thermal effects strongly correlated with urban development densities where higher percent

imperviousness is usually associated with higher surface temperature. Using vegetation canopy

coverage information, the spatial and temporal distributions of urban impervious surface and

associated thermal characteristics are demonstrated to be very useful sources in quantifying

urban land use, development intensity, and urban thermal patterns.

Tyrvainen, L., et al. (2006). "Visualization and landscape laboratories in planning, design

and management of urban woodlands." Forest Policy and Economics 8(8): 811-823.

Although participatory approaches are increasingly used in planning and management of

urban woodlands, efficient tools are also needed to make the processes work. In urban forest

planning impacts of proposed management regimes on aesthetic and recreational values are

among the factors that interest the local residents the most. This article explores two potential

methods for improving collaborative urban forest planning and design in Europe, based primarily

on experience gained in the Nordic countries. The methods relate to the use of (i) computer-

based visualization methods and (ii) demonstration forests and landscape laboratories. We

suggest that use of both methods may lead to a major enhancement in forest planning and design.

Pataki, D. E., et al. (2006). "Urban ecosystems and the North American carbon cycle."

Global Change Biology 12(11): 2092-2102.

Approximately 75-80% of the population of North America currently lives in urban areas

as defined by national census bureaus, and urbanization is continuing to increase. Future

trajectories of fossil fuel emissions are associated with a high degree of uncertainty; however, if

the activities of urban residents and the rate of urban land conversion can be captured in urban

systems models, plausible emissions scenarios from major cities may be generated. Integrated

land use and transportation models that simulate energy use and traffic-related emissions are

already in place in many North American cities. To these can be added a growing dataset of

carbon gains and losses in vegetation and soils following urbanization, and a number of methods

of validating urban carbon balance modeling, including top down atmospheric monitoring and

urban 'metabolic' studies of whole ecosystem mass and energy flow. Here, we review the state of

our understanding of urban areas as whole ecosystems with regard to carbon balance, including

both drivers of fossil fuel emissions and carbon cycling in urban plants and soils.

Interdisciplinary, whole-ecosystem studies of the socioeconomic and biophysical factors that

influence urban carbon cycles in a range of cities may greatly contribute to improving scenarios

of future carbon balance at both continental and global scales.

Nowak, D. J., et al. (2006). "Air pollution removal by urban trees and shrubs in the United

States." Urban Forestry Urban Greening 4.

A modeling study using hourly meteorological and pollution concentration data from

across the coterminous United States demonstrates that urban trees remove large amounts of air

pollution that consequently improve urban air quality. Pollution removal (O3, PM10, NO2, SO2,

CO) varied among cities with total annual air pollution removal by US urban trees estimated at

711,000 metric tons ($3.8 billion value). Pollution removal is only one of various ways that

urban trees affect air quality. Integrated studies of tree effects on air pollution reveal that

management of urban tree canopy cover could be a viable strategy to improve air quality and

help meet clean air standards.

Li, W. F., et al. (2006). "Plant species composition in relation to green cover configuration

and function of urban parks in Beijing, China." Ecological Research 21(2): 221-237.

Parks, as one specific type of urban open space, play important roles in the conservation

of urban biodiversity and provision of recreational services for local residents. As there is a lack

of specific insight into park plant species composition in relation to park features, 24 sample

parks within the inner city of Beijing, the capital of China, were studied by stratified random plot

sampling of their tree, shrub, and herbaceous communities, respectively, in order to investigate

how human activities have influenced park green cover configuration and floristic

characteristics. The quantitative correlation of species richness and the park green cover indices

(patch size, shape, etc.) were studied. The importance value index for plant species (trees, shrubs,

and herbaceous species) of each park was calculated. The two-way indicator species analysis

approach (TWINSPAN) was applied to classify the 24 parks into different groups based on their

species assemblages. Two-hundred and eighty-eight species were recorded within the 24 study

parks, belonging to 184 genera and 72 families dominated by Gramineae, Compositae, and

Leguminosae. Among all the recorded species, 41% are exotic. The species occurrence,

abundance and diversity vary significantly among different parks. Besides the positive

correlation (R=0.505, P < 0.05) between herbaceous species abundance and the park green cover

size, no other significant relations were found between the species abundance and other indices

of park green cover configuration. Remarkably, the TWINSPAN classification resulted in a good

discrimination between park functional types and the variation in their species assemblage. For

the parks of similar age (development history) or landscape design, their species assemblages

show more similarity. The methodology adopted and results can be employed to improve

baseline information on urban plant ecology and support the setting of priorities for future park

management and vegetation protection.

Lavelle, P., et al. (2006). "Soil invertebrates and ecosystem services." European Journal of

Soil Biology 42(Supplement 1): S3-S15.

Invertebrates play significant, but largely ignored, roles in the delivery of ecosystem

services by soils at plot and landscape scales. They participate actively in the interactions that

develop in soil among physical, chemical and biological processes. We show that soils have all

the attributes of self-organized systems as proposed by Perry (Trends Ecol. Evol. 10 (1995) 241)

and detail the scales at which invertebrates operate and the different kinds of ecosystem

engineering that they develop. This comprehensive analysis of invertebrate activities shows that

they may be the best possible indicators of soil quality. They should also be con- sidered as a

resource that needs to be properly managed to enhance ecosystem services provided by agro-

ecosystems.

Klumpp, A., et al. (2006). "Ozone pollution and ozone biomonitoring in European cities.

Part I: Ozone concentrations and cumulative exposure indices at urban and suburban

sites." Atmospheric Environment 40(40): 7963-7974.

In the frame of a European research project on air quality in urban agglomerations, data

on ozone concentrations from 23 automated urban and suburban monitoring stations in 11 cities

from seven countries were analysed and evaluated. Daily and summer mean and maximum

concentrations were computed based on hourly mean values, and cumulative ozone exposure

indices (Accumulated exposure Over a Threshold of 40 ppb (AOT40), AOT20) were calculated.

The diurnal profiles showed a characteristic pattern in most city centres, with minimum values in

the early morning hours, a strong rise during the morning, peak concentrations in the afternoon,

and a decline during the night. The widest amplitudes between minimum and maximum values

were found in central and southern European cities such as Dusseldorf, Verona, Klagenfurt,

Lyon or Barcelona. In the northern European cities of Edinburgh and Copenhagen, by contrast.

maximum values were lower and diurnal variation was much smaller. Based on ozone

concentrations as well as on cumulative exposure indices, a clear north-south gradient in ozone

pollution, with increasing levels from northern and northwestern sites to central and southern

European sites, was observed. Only the Spanish cities did not fit this pattern; there, ozone levels

were again lower than in central European cities, probably due to the direct influence of strong

car traffic emissions. In general, ozone concentrations and cumulative exposure were

significantly higher at suburban sites than at urban and traffic-exposed sites. When applying the

newly established European Union (EU) Directive on ozone pollution in ambient air, it was

demonstrated that the target value for the protection of human health was regularly surpassed at

urban as well as suburban sites, particularly in cities in Austria, France, northern Italy and

southern Germany. European target values and long-term objectives for the protection of

vegetation expressed as AOT40 were also exceeded at many monitoring sites.

Jenerette, G. D., et al. (2006). "Linking ecological footprints with ecosystem valuation in

the provisioning of urban freshwater." Ecological Economics 59(1): 38-47.

Two prominent and alternate approaches, ecosystem service valuation and ecological

footprints, link the production of ecosystem services with their consumption by societies. An

overlapping goal of both approaches is to promote the sustainable use of ecosystem services such

that their production rates are not compromised. Yet, little integration of these perspectives and

their emphasis on distinct units, dollars and area, has been attempted. We combined these two

approaches to better understand variation in the societal demand and production of freshwater, a

critical ecosystem service, for 121 cities in the United States. The analysis linked previously

compiled data on urban water use and the spatial distribution of run-off water throughout the

conterminous United States. Incorporating the spatial distribution of water consumption and

production, we computed heterogeneous urban water use footprints for all 121 cities. From the

relationship between annual municipal utility expense and footprint area, the median monetary

value for water footprint area was $88,808 km(-2) yr(-1) from all the cities we considered. The

ratio between the footprint-estimated cost and the utility-observed cost was negatively related to

the local availability of water, and was independent of population size. By linking ecosystem

service valuation and ecological footprint analyses into a coherent framework, we developed an

integrated metric for understanding the provisioning of ecosystem services, which could help

inform sustainable pricing guidelines for renewable freshwater.

Jenerette, G. D. and L. Larsen (2006). "A global perspective on changing sustainable urban

water supplies." Global and Planetary Change 50(3-4): 202-211.

Ensuring the sustainable supply of water for the world's largest cities has been and is a

current challenge. Future trends in urban water consumption patterns will be determined by

changes in population concentration, per-capita water use, climate, and the proportion of water

retained for the production of instream ecosystem services. The objective of our research was to

identify patterns of renewable water availability and urban consumption throughout the globe

between the years 2000 and 2015. To better understand the interactions between urban

consumption and regional availability of renewable water we used a modified ecological

footprint (EF) approach. Urban water footprint areas were differentially sensitive to changes in

consumption and changes in water availability; our results suggest climate induced reductions in

water availability may be more of a concern than population growth or increased per-capita for

securing continued supplies of water to large cities. Our results provide a comprehensive

description of global urban water demand and highlight the variation between consumption and

availability relationships for the 524 largest cities.

Hodgson, P., et al. (2006). "Comparison of foraging behaviour of small, urban-sensitive

insectivores in continuous woodland and woodland remnants in a suburban landscape."

Wildlife Research 33(7): 591-603.

Small patches of remnant vegetation are often considered to have low conservation value.

In urban landscapes their value may potentially be higher than in other landscapes because they

can be the only representatives of original native vegetation. Despite this potential, many small

insectivorous birds that rely on native vegetation demonstrate sensitivities within urban

landscapes through reduced numbers or total absence. One reason for this sensitivity may be that

remnants are of suboptimal quality, which may be reflected in behavioural changes. Using five

insectivorous species that were present ( in low numbers) in remnants surrounded by highdensity

housing, foraging behaviour was examined in relation to vegetation. The proportion of time birds

spent on different foraging substrates and plant species was compared with that of conspecifics

in continuous vegetation. Canopy and shrub foragers showed minimal behavioural changes.

Ground foragers in remnants tended to forage at lower heights than those in continuous

vegetation; however, these changes did not appear to reflect a negative effect. These changes

were partially explained by structural differences between vegetation in remnants and continuous

sites. The number of times a bird attacked prey items was significantly higher in continuous

habitat for only two species. Overall, the foraging behaviour of small insectivorous birds in

remnants surrounded by high- density housing was not adversely affected by urbanisation and it

appears that remnants have potential value as habitat and foraging sources in an urban landscape.

Despite this, small insectivores are still sensitive to urbanisation, suggesting that other factors,

probably in the matrix, are important.

Georgi, N. and K. Zafiriadis (2006). "The impact of park trees on microclimate in urban

areas." Urban Ecosystems 9(3): 195-209.

Trees in cities have an important positive effect on people’s lives. One such positive

effect is the amelioration of microclimate. The aim of this research is to assess the correlation

between parameters that affect the microclimate of parks during the summer. We measured air

temperature, relative humidity and solar radiation in the sun and shade of the trees in urban parks

in Thessaloniki, Greece. The results indicate that: the air (A) temperature reduction percentage

(dTair%), air relative humidity increase (dTRh%), discontent index reduction percentage (DI%)

(cooling effect) and solar radiation (L) percentage that passes through the trees’ foliage to their

shade creates an exponential function of dA% = a.e-bL. These functions are also applicable to

the limiting variation values of the parameters. If we use L = 0 (meaning Lightsh = 0, which is

the case for an extremely dense tree), then the values that we expect from this particular

parameter are the maximum possible. These maximum values are a characteristic feature of the

parameter variation for this particular research area. These maximum values for the trees in the

parks of Thessaloniki are: maxdTair% ≈ 24%, maxdRh% ≈ 41% and maxdDI% ≈16%.

Fanelli, G., et al. (2006). "Ecological indicators applied to urban and suburban floras."

Ecological Indicators 6(2): 444-457.

Among the many approaches to ecological indicators, ecological indicators derived from

the floristic composition of a site (i.e. Raunkiaer's forms spectrum or the percentage of different

geographical distribution types-chorotypes) are well established in botanical and ecological

literature. Nonetheless their relationship with other indicators, such as Ellenberg's ecological

indicators, or the Grime model [Grime, J.P., 2002. Plant Strategies, Vegetation Processes and

Ecosystem Properties. Wiley, Chichester] and the Hemeroby index [Kowarik, L, 1990. Some

responses of flora and vegetation to urbanization in Central Europe. In: Sukopp, H., Hejny, S.,

Kowarik, I. (Eds.), Urban Ecology. Plants and plant communities in urban environments. SPB

Academic Publishing, The Hague] is still poorly explored. We concentrated on an urban

ecosystem because such areas, due to their high degree of artificialization, are particularly well

suited for studying the interaction of anthropical disturbance with other processes of the

ecosystems. This paper attempts to select a small indicator frameset of many already proposed

indicators which best express the variability of the sites studied. A floristic-ecological

investigation has been carried out in 10 urban sites, of which 6 were archeological, located in the

centre of Rome and 4 suburban, semi-natural, in the NE of the town. Ecological indicators have

been calculated on this data set. The Pearson correlation test was then applied to verify whether

the indicators were independent, while stepwise regression analysis was done to evaluate the

statistical weight of each ecoindicator. Disturbance and temperature are the main factors shaping

the composition of the sites studied. They are largely interacting and are well expressed with the

help of a small subset of the initial set of 19 indicators, namely, by indicators related to life forms

and to the geographical distribution of species: Therophytes/Hemicryptophytes,

Mediterranean/large distribution, Eurasiatic/ large distribution, Mediterranean/Eurasiatic species.

The information provided by Ellenberg's indicators values and Grime's life strategies are largely

summarized by these chorological indicators.

Crow, T., et al. (2006). "The Riverside and Berwyn experience: Contrasts in landscape

structure, perceptions of the urban landscape, and their effects on people." Landscape and

Urban Planning 75(3-4): 282-299.

Humans not only structure the landscape through their activities, but their perceptions of

nature are affected by the spatial and temporal arrangements (structure) in the landscape. Our

understanding of these interactions, however, is limited. We explored the relationship between

landscape structure and peoples' perceptions of nature in the Chicago, IL, USA, suburbs of

Riverside and Berwyn because they offer contrasting paradigms of an urban landscape. Designed

in the 1800s by Frederick Law Olmsted, Riverside has several unique design elements

(curvilinear streets, ample setbacks, parkways of variable width with mowed grass and

naturalistic groupings of trees) that define the structure and composition of this landscape. The

urban forest was the keystone of Olmsted's desire to create a harmonious community

characterized by "refined sylvan beauty". In contrast, the adjacent community of Berwyn has

right-angled streets with small lots and narrow setbacks for houses. Differences in landscape

structure between the two communities produced differences in the diversity, size, and

composition of woody vegetation. As measured by patch-size distribution, Riverside had greater

diversity in landscape structure than Berwyn, and in turn, Riverside had greater diversity in the

composition and size of the woody vegetation compared to Berwyn. Riverside tended toward a

"natural" appearance with vegetation, while yards in Berwyn tended to be trimmed and edged.

Significant differences between the mean ratings of Riverside and Berwyn respondents were

found for six of seven community attribute categories. Riverside participants reported receiving

greater benefit from the visual and nature-related features of the urban forest than did Berwyn

respondents. Berwyn residents ranked social atmosphere for the community and locomotion

(wayfinding) highest among the seven community attribute categories. Despite differences

between the two communities, residents valued the green residential environment provided by

vegetation. However, the more diverse urban landscape as measured by built structures, woody

vegetation, and lot size and shape proved to be more satisfying to the residents of these two

communities. The design concepts developed and implemented by Olmsted more than century

ago in Riverside are still relevant to city planners striving to develop living environments that are

satisfying to urban and suburban residents.

Borgstrom, S. T., et al. (2006). "Scale mismatches in management of urban landscapes."

Ecology and Society 11(2).

Urban landscapes constitute the future environment for most of the world's human

population. An increased understanding of the urbanization process and of the effects of

urbanization at multiple scales is, therefore, key to ensuring human well-being. In many

conventional natural resource management regimes, incomplete knowledge of ecosystem

dynamics and institutional constraints often leads to institutional management frameworks that

do not match the scale of ecological patterns and processes. In this paper, we argue that scale

mismatches are particularly pronounced in urban landscapes. Urban green spaces provide

numerous important ecosystem services to urban citizens, and the management of these urban

green spaces, including recognition of scales, is crucial to the well-being of the citizens. From a

qualitative study of the current management practices in five urban green spaces within the

Greater Stockholm Metropolitan Area, Sweden, we found that 1) several spatial, temporal, and

functional scales are recognized, but the cross-scale interactions are often neglected, and 2)

spatial and temporal meso-scales are seldom given priority. One potential effect of the neglect of

ecological cross-scale interactions in these highly fragmented landscapes is a gradual reduction

in the capacity of the ecosystems to provide ecosystem services. Two important strategies for

overcoming urban scale mismatches are suggested: 1) development of an integrative view of the

whole urban social -ecological landscape, and 2) creation of adaptive governance systems to

support practical management.

Boeckx, P., et al. (2006). "Spatial patterns of delta C-13 and delta N-15 in the urban topsoil

of Gent, Belgium." Organic Geochemistry 37(10): 1383-1393.

Urban ecosystems are characterized by a diverse land use pattern, strongly influenced by

anthropogenic activities. The aim of this study was to assess whether the spatial distribution of

delta N-15 and delta C-13 signatures in soil and plants could be reflected in patterns of functional

urban land use. The study area (81.5 km(2)) was the city of Gent in Belgium. In the study area

200 sample locations were identified and the delta N-15 and delta C-13 signature of soil (0-5 cm)

and grass samples was measured. The spatial structure of the isotopic distribution has been

investigated using simple kriging with land use as complete categorical secondary information.

The delta N-15(soil) and delta N-15(grass) data varied between -1.5 parts per thousand to 11.7

parts per thousand and -4.0 parts per thousand to 16.2 parts per thousand, respectively. The delta

C-13(soil) and delta C-13(grass) data varied between -30.7 parts per thousand to -12.0 parts per

thousand and -33.8 parts per thousand to -19.9 parts per thousand, respectively. Despite the

overlapping standard deviations, the average delta N-15(soil), delta N-15(grass), delta C-13(soil),

delta C-13(grass) data showed a clear land use dependent pattern. The delta N-15(soil), values

showed the highest continuity with land use. The agricultural areas showed the highest delta N-

15(soil) data, which could be attributed to a more open N cycle and the loss of N-15 depleted N

species or the use of N-15 enriched organic fertilizers. The wet grasslands of the nature reserves

also showed higher delta N-15(soil) data, probably caused by enhanced denitrification losses.

Urban greens showed the lowest delta N-15(soil) data, which could be explained by the absence

of fertilizer input and the presence of N-2-fixing species (clover). The historic city centre and the

residential areas showed average delta N-15(soil) data. The delta N-15(grass) correspond very

well to the delta N-15(soil) data, but the delta N-15(grass) data were on average 1.1 parts per

thousand depleted and showed a more random distribution. The delta C-13(soil) data indicated

the introduction of maize (C4 plant) in agriculture, causing an increase of the delta C-13(soil)

values of the agricultural zone of the study area. The wet grasslands of the nature reserves

showed the lowest C3-signals in delta C-13(soil). The harbor area and the historic city centre and

some isolated industrial sites showed the highest delta C-13(soil) data. These high values can be

explained through the introduction of carbonate-rich materials from, e.g. constructions material,

metallurgic activities, use of carbonate rich soils for the construction works and bulk C

deposition (e.g. coal dust). It could be concluded that the stable isotopic composition of the

topsoil and grass showed a moderate to strong relationship with land use of the studied urban

ecosystem.

Andersson, E. (2006). "Urban landscapes and sustainable cities." Ecology and Society

11(1): 34.

Ecological research targeting sustainable urban landscapes needs to include findings and

methods from many lines of ecological research, such as the link between biodiversity and

ecosystem function, the role of humans in ecosystems, landscape connectivity, and resilience.

This paper reviews and highlights the importance of these issues for sustainable use of ecosystem

services, which is argued to be one aspect of sustainable cities. The paper stresses the need to

include social and economic factors when analyzing urban landscapes. Spatially explicit data can

be used to assess the roles different green areas have in providing people with ecosystem

services, and whether people actually have access to the services. Such data can also be used to

assess connectivity and heterogeneity, both argued to be central for continuous, long-term

provision of these services, and to determine the role urban form has for sustainability.

Schroter, D., et al. (2005). "Ecosystem service supply and vulnerability to global change in

Europe." Science 310(5752): 1333-1337.

Global change will alter the supply of ecosystem services that are vital for human well-

being. To investigate ecosystem service supply during the 21st century, we used a range of

ecosystem models and scenarios of climate and land-use change to conduct a Europe-wide

assessment. Large changes in climate and land use typically resulted in large changes in

ecosystem service supply. Some of these trends may be positive (for example, increases in forest

area and productivity) or offer opportunities (for example, "surplus land" for agricultural

extensification and bioenergy production). However, many changes increase vulnerability as a

result of a decreasing supply of ecosystem services (for example, declining soil fertility,

declining water availability, increasing risk of forest fires), especially in the Mediterranean and

mountain regions.

Scharenbroch, B. C., et al. (2005). "Distinguishing urban soils with physical, chemical, and

biological properties." Pedobiologia 49(4): 283-296.

Modifications associated with urban infrastructure directly impact soil. properties. In

particular, soil bulk density, microbial biomass and activity, and organic matter are impacted by

anthropogenic activities. We proposed that urban soil properties are not only distinguishable

from other systems, but also variable within types of landscapes in urban environments. We

found soils from older urban landscapes (mean landscape age of 64 years) to be distinct from

newer urban landscapes (mean landscape age of 9 years). Soil bulk densities were significantly

greater in newer (1.73 g cm(-3)) compared to older urban soils (1.41 g cm(-3)) Older urban soils

had significantly greater extractable phosphorous, weak Bray P (24%), strong Bray P (51%), and

K (45%) than newer urban soils. Soil. biological measures of nitrogen availability were

significantly greater in old compared to new urban soils, microbial biomass N (71%), potential C

mineralization (20%), and potential N mineralization (83%). We found exponentially decreasing

metabolic quotient values, qCO(2), suggesting the impact of site disturbance decreases rapidly

with time, and older urban landscapes are closer to steady-state conditions relative to younger

urban Landscapes. Total soil organic matter was significantly greater (35%) in old urban soils.

Fine POM was a larger contributor to total SOM in old compared to new urban soils. Particulate

organic matter C/N ratios from older urban soils were less (coarse POM 14% less and fine POM

13% less) than newer urban soils. Of the soil forming factors, time played the most significant

rote in soil physical, chemical, and biological differences. We believe that as time since initial

disturbance increases, the impacts of urbanization are reduced by processes improving physical,

biological, and chemical soil properties.

McPherson, E. G. and J. Muchnick (2005). "Effects of Street Tree Shade on Asphalt

Concrete Pavement Performance." Journal of Arboriculture 31(6): 303-310.

Forty-eight street segments were paired into 24 highand low-shade pairs in Modesto,

California, U.S. Field data were collected to calculate a Pavement Condition Index (PCI) and

Tree Shade Index (TSI) for each segment. Statistical analyses found that greater PCI was

associated with greater TSI, indicating that tree shade was partially responsible for reduced

pavement fatigue cracking, rutting, shoving, and other distress. Using observed relations between

PCI and TSI, an unshaded street segment required 6 slurry seals over 30 years, while an identical

one planted with 12 crape myrtles (Lagerstroemia indica, 4.4 m [14 ft] crown diameter) required

5 slurry seals, and one with 6 Chinese hackberry (Celtis sinensis, 13.7 m [45 ft] crown diameter)

required 2.5 slurry seals. Shade from the large hackberries was projected to save $7.13/m2

($0.66/ft2) over the 30-year period compared to the unshaded street.

Li, F., et al. (2005). "Comprehensive concept planning of urban greening based on

ecological principles: a case study in Beijing, China." Landscape and Urban Planning

72(4): 325-336.

Greenspace is an important part of complex urban ecosystems and provides significant

ecosystem services. It benefits urban communities environmentally, esthetically, recreationally

and economically. Beijing Province is in north of China, and has a total area of 16,807.8 km(2)

and a population of about 13.8 million. This paper aims to develop a comprehensive conceptual

framework for urban greening of Beijing Province based on landscape ecological principles. It

attempts to answer how to establish an urban greening plan at the regional, city and

neighborhood levels to achieve long-term sustainability. At the regional level, a big natural and

semi-natural forest area in the northwest and an ecological buffer belt in the southeast are

planned to protect the environmental quality of Beijing and provide habitats for wildlife. At the

city level, a green network system of green wedges, parks and green corridors has been

proposed. This green network helps to limit future urban expansion, improve urban

environmental quality and serve as habitats and migration routes for wildlife. At the

neighborhood level, green extensions and connections of riverside greenway, road greenway,

parks and vertical greening permeate into the built-up areas. They provide open space close to

residential areas and offer places for recreation. This three-level green system constitutes an

integrated ecological network for urban sustainable development of Beijing. For future

development of Beijing, urban parks, forestry, agriculture, water and infrastructure should be

planned and designed in an integrated way. After this greenspace plan is legislated and

completely realized, Beijing will develop an interconnected and integrated network of urban

greenspaces. It has the prospect of achieving the aim of "Green Olympic City 2008" and the

long-term goal of developing Beijing towards an "Eco-City".

Lepedus, H., et al. (2005). "Photosystem II efficiency, chloroplast pigments and fine

structure in previous-season needles of Norway spruce (Picea abies L. Karst.) affected by

urban pollution." Periodicum Biologorum 107(3): 329-333.

Industry and road traffic are considered to be main sources of air pollutants in urban

areas. Changes in chloroplast structure, biochemistry and function appeared as very fast and

reliable indicators of stress conditions. The arm of our study was to compare the needles of

Norway spruce trees growing on differently polluted sites in the city of Osijek (Croatia)

regarding photosynthetic pigment content, chloroplast ultra-structure and the efficiency of

photosystem II.

Materials for the study were previous-season needles collected from the middle crown of

ten, about 25 year-old cultivated Norway spruce (Picae abies L. Karst.) trees grown in the City of

Os jell, Croatia. According to the data on pollution levels obtained from the Croatian National

Institute of Public Health, two sampling plots were defined: less (reference) and more polluted.

Photosynthetic pigments were extracted with absolute acetone and quantified

spectrophotometrically. For electron microscopy, the plant material was fixed in glutaraldehyde,

dehydrated and embedded in Spurr's resin. Ultrathin sections were contrasted with lead citrate

and uranyl acetate. The measurements of chlorophyll fluorescence were performed with the

pulse-amplitude-modulated photosynthesis yield analyser (Mini-PAM, Waltz), using pulse-

saturating method. The plant material was dark-adapted for 30 minutes. Minimal (Fo) and

maximal (Fin) fluorescence yields were measured in the dark-adapted samples. The same

parameters (F and Pin, respectively) were measured at two different irradiance levels: low light

(125 mu mol(PHOTONS) m(-2)z s(-1)) and high light (1400 mu mol(PHOTONS) m(-2) s(-1)).

The concentration of photosynthetic pigments was lower in more affected needles than in

the reference ones. However; only changes in chlorophyll b revealed statistical signficance,

increasing the chlorophyll a to chlorophyll b ratio. Chloroplast ultrastructure and shape were

changed in more affected needles: these chloroplasts were roundish with much bigger starch

grains and snore pronounced thylakoid swelling than the chloroplast from the reference needles.

Maximal photochemical efficiency of photosystem II (Fv/Fm) measured in the dark-adapted

samples teas almost the same for both samples, while lower values of the effective quantum yield

of photosystem II (Delta F/F'm) were determined in more affected needles. It can be concluded

that after a prolonged period of exposure to a higher pollution level (two years), spruce needles

revealed biochemical, ultrastructural and functional changes when compared with the needles

exposed to a lower pollution level.

Latalowa, M., et al. (2005). "Diurnal patterns of airborne pollen concentration of the

selected tree and herb taxa in Gdansk (northern Poland)." Grana 44.

The diurnal variation of airborne pollen concentrations of Alnus, Betula, Pinus, Poaceae,

Urtica and Artemisia was examined at the sampling station in Gdańsk, northern Poland. Diurnal

patterns of Alnus and Pinus pollen show distinctly lower values and low frequency of diurnal

maxima between midnight and late morning and a clear rise of pollen counts at around noon. The

rather high values remain during the afternoon and evening. The Betula pollen counts are almost

evenly distributed along day and night and diurnal maxima appear in similar frequency at any

time of day. Pollen concentrations of Poaceae increase at about 9.00 hours and remain high till

late evening. Diurnal patterns of Urtica and Artemisia show very clear variation with high peaks

at around 9.00 hours (Artemisia) and 13.00 hours (Urtica). The comparison of the data from

Gdańsk with the data from other aerobiological stations shows very similar general features in

the diurnal patterns irrespective the region or the local situation.

Kanakidou, M., et al. (2005). "Organic aerosol and global climate modelling: a review."

Atmos Chem Phys 5.

The present paper reviews existing knowledge with regard to Organic Aerosol (OA) of

importance for global climate modelling and defines critical gaps needed to reduce the involved

uncertainties. All pieces required for the representation of OA in a global climate model are

sketched out with special attention to Secondary Organic Aerosol (SOA): The emission estimates

of primary carbona- ceous particles and SOA precursor gases are summarized. The up-to-date

understanding of the chemical formation and transformation of condensable organic material is

outlined. Knowledge on the hygroscopicity of OA and measurements of optical properties of the

organic aerosol constituents are summarized. The mechanisms of interactions of OA with clouds

and dry and wet removal processes parameterisations in global models are outlined. This

information is synthe- sized to provide a continuous analysis of the flow from the emitted

material to the atmosphere up to the point of the cli- mate impact of the produced organic

aerosol. The sources of uncertainties at each step of this process are highlighted as areas that

require further studies.

Hill, S. J., et al. (2005). "Relationships between anthropogenic disturbance, soil properties

and plant invasion in endangered Cumberland Plain Woodland, Australia." Austral

Ecology 30(7): 775-788.

Invasive exotic plants are a significant threat to areas of conservation value, with

endangered ecological communities being especially vulnerable. We assessed the role of

different anthropogenic disturbances in determining the success of exotic plants in the

endangered Cumberland Plain Woodland community of western Sydney and examined the

impact of these disturbances on soil characteristics that are likely to impact on vegetation,

including total P, pH, water retention capacity, organic matter content and electrical

conductivity. The disturbance types were: (i) land use incorporating clearing, agriculture and

grazing by stock; (ii) creeks draining a developed catchment; and (iii) roads. Remnants that had

been cleared and grazed had higher exotic and lower native species richness and cover than all

other disturbance types. Areas that had been grazed but not cleared did not have more exotic

species richness or cover than uncleared/ungrazed areas, thus retaining high conservation value.

Areas within 2 m of a creek edge had higher exotic species richness and cover than areas further

from the creek edge. Areas downslope of sealed roads had significantly higher exotic species

richness and cover than areas below unsealed roads. No single soil attribute or combination of

soil attributes was consistently able to account for variation in exotic species cover under the

different disturbance types. Thus it appears that other factors such as site history and propagule

pressure may be more important in determining exotic species success than soil characteristics

alone, in this vegetation community.

Grimm, N. B., et al. (2005). "N retention and transformation in urban streams." Journal of

the North American Benthological Society 24(3): 626-642.

Nutrient spiraling in theory and application provides a framework for comparing nutrient

retention efficiency of urban streams to relatively unaltered streams. Previous research indicated

that streams of the southwestern USA deserts are highly retentive of N because of N limitation,

high productivity, and high channel complexity (in particular, extensive transient storage

associated with the hyporheic zone). Most southwestern urban streams have extensively

modified channels and experience N loading from urban runoff and inputs of NO3--

contaminated groundwater. Therefore, we predicted southwestern urban streams are neither N-

limited nor retentive. For some urban streams, however, restoration efforts reestablish flow in

long-dry channels, create nonstructural flood-management solutions, and design riparian areas as

a public recreation amenity. These human modifications may, in part, restore N retention

functions if channel complexity and heterogeneity are as important to N retention efficiency as

believed. We conducted experimental tracer studies using NO3-, as part of the Lotic Intersite

Nitrogen eXperiment (LINX) project, and several separate nutrient-addition experiments (using

slight increases in NO3- concentration), to evaluate N retention in southwestern urban streams.

We present preliminary results of those experiments, comparing results to similar experiments in

unaltered streams to test our predictions. Our results allow an evaluation of the use of nutrient

spiraling metrics as a tool for assessing the status of stream ecosystem services in urban

restoration projects.

Gaston, K. J., et al. (2005). "Urban domestic gardens (II): experimental tests of methods

for increasing biodiversity." Biodiversity and Conservation 14(2): 395-413.

The extent and continued expansion of urbanisation has focused attention on the

significance for native biodiversity of those green spaces remaining within such areas and the

most appropriate methods of managing them. In the UK, a high proportion of urban space is

comprised of the private or domestic gardens associated with residential dwellings, and many

recommendations have been made for simple changes to improve their value for biodiversity

('wildlife gardening'). Here, we report the results of replicated experimental tests of five such

common recommendations, involving the introduction to gardens of (i) artificial nest sites for

solitary bees and wasps; (ii) artificial nest sites for bumblebees; (iii) small ponds; (iv) dead wood

for fungi and other saproxylic organisms; and ( v) patches of nettles Urtica dioica L. for butterfly

larvae. The broad conclusion is that whilst some methods for increasing the biodiversity of

garden environments may be very effective, others have a low probability of success on the

timescales and spatial scales likely to be acceptable to many garden owners. If one of the

functions of small scale biodiversity enhancement is to develop and encourage awareness of

biodiversity and its conservation, then encouragement to conduct particular activities must be

balanced with a realistic appraisal of their likely success.

Ehrenfeld, J. G. (2005). "Vegetation of forested wetlands in urban and suburban

landscapes in New Jersey." Journal of the Torrey Botanical Society 132(2): 262-279.

Forested wetlands in the northeastern US are increasingly surrounded by urban and

suburban land-use, as development spreads outwards from city centers. I have studied a sample

of 21 mature deciduous forested wetlands in a densely populated and long-settled region,

northeastern New Jersey, in order to 1) describe characteristics of the plant communities of

wetlands in such human-dominated landscapes, and 2) test the utility of hydrogeomorphic

classification (HGM) in explaining the variation in composition and structure observed among

the sites. The wetlands support a rich flora of over 300 species, with a mean richness of 66-92

species per site for the different HGM classes; common species were similar to those reported in

previous studies of undisturbed red maple swamps. Structural characteristics (tree diameter and

stem densities) were, like species richness and species composition, similar to those reported in

previous reviews of red maple swamps, suggesting that despite the urban setting, community

composition and structure of these wetlands are similar to those of undisturbed wetlands. Exotic

species represented on average 5-11 % of the flora of the sites, a value similar to other forested

wetlands, suggesting that the urban setting does not result in a higher degree of exotic invasion

than expected for forested wetlands in non-urban landscapes. HGM classification was poorly

related to all aspects of vegetation structure, suggesting that at least in urban landscapes, it is not

useful for predicting characteristics of the vegetation. The ability of these communities to resist

major changes due to the urban setting may reflect the facultative-wetland status of most of the

species; their ability to tolerate a wide range of wetland conditions allows them to persist despite

alterations of hydrological regimes. Forested wetlands in developed landscapes can evidently

maintain community composition and structure similar to those in undeveloped landscapes.

Donovan, R. G., et al. (2005). "Development and application of an urban tree air quality

score for photochemical pollution episodes using the Birmingham, United Kingdom, area

as a case study." Environ Sci Technol 39.

An atmospheric chemistry model (CiTTyCAT) is used to quantify the effects of trees on

urban air quality in scenarios of high photochemical pollution. The combined effects of both

pollutant deposition to and emission of biogenic volatile organic compounds (BVOC) from the

urban forest are considered, and the West Midlands, metropolitan area in the UK is used as a

case study. While all trees can be beneficial to air quality in terms of the deposition of O3, NO2,

CO, and HNO3, some trees have the potential to contribute to the formation of O3 due to the

reaction of BVOC and NOx. A number of model scenarios are used to develop an urban tree air

quality score (UTAQS) that ranks trees in order of their potential to improve air quality. Of the

30 species considered, pine, larch, and silver birch have the greatest potential to improve urban

air quality, while oaks, willows, and poplars can worsen downwind air quality if planted in very

large numbers. The UTAQS classification is designed with practitioners in mind, to help them

achieve sustainable urban air quality. The UTAQS classification is applicable to all urban areas

of the UK and other mid-latitude, temperate climate zones that have tree species common to

those found in UK urban areas. The modeling approach used here is directly applicable to all

areas of the world given the appropriate input data. It provides a tool that can help to achieve

future sustainable urban air quality.

Dlugosch, K. M. (2005). "Understory community changes associated with English ivy

invasions in Seattle's urban parks." Northwest Science 79(1): 53-60.

English ivy has become a common invader in Seattle's urban parks and in forests

throughout the Pacific Northwest. Despite a great deal of concern over the potential impacts of

this species, no studies have investigated ivy's effects on native vegetation in this region. In this

study, paired comparisons between ivy-invaded and adjacent non-invaded plots in three Seattle

parks were used to quantify changes associated with ivy invasion in the forest understory.

Species diversity, percent cover, and tree regeneration were surveyed. Differences in species

diversity, calculated as both richness and evenness, were not significantly different between

invaded and non-invaded plots. Ivy-invaded plots did have significantly higher total cover, and

significantly lower non-ivy cover, than non-invaded plots. The reduction of percent cover in

invaded plots was primarily due to the loss of native shrubs. A plot where ivy had been removed

over five years was also surveyed, and percent cover in this plot showed intermediate values

relative to invaded and non-invaded plots, for both total cover and cover of native shrubs. The

number of trees regenerating in the understory was higher in invaded plots, though this

difference was not significant. These results suggest that English ivy invasions have substantial

impacts on understory cover, and may influence the species composition and diversity of forest

communities over the long-term by increasing vegetative cover and suppressing dominant native

shrubs.

Carreiro, M. M. and C. E. Tripler (2005). "Forest remnants along urban-rural gradients:

Examining their potential for global change research." Ecosystems 8(5): 568-582.

Over the next century, ecosystems throughout the world will be responding to rapid

changes in climate and rising levels of carbon dioxide, inorganic N and ozone. Because people

depend on biological systems for water, food and other ecosystem services, predicting the range

of responses to global change for various ecosystem types in different geographic locations is a

high priority. Modeling exercises and manipulative experimentation have been the principle

approaches used to place upper and lower bounds on community and ecosystem responses.

However, each of these approaches has recognized limitations. Manipulative experiments cannot

vary all the relevant factors and are often performed at small spatio-temporal scales. Modeling is

limited by data availability and by our knowledge of how current observations translate into

future conditions. These weaknesses would improve if we could observe ecosystems that have

already responded to global change factors and thus presage shifts in ecosystem structure and

function. Here we consider whether urban forest remnants might offer this ability. As urban

forests have been exposed to elevated temperature, carbon dioxide, nitrogen deposition and

ozone for many decades, they may be ahead of the global change "response curve" for forests in

their region. Therefore, not only might forests along urbanization gradients provide us with

natural experiments for studying current responses to global change factors, but their legacy of

response to past urbanization may also constitute space-for-time substitution experiments for

predicting likely regional forest responses to continued environmental change. For this approach

to be successful, appropriate criteria must be developed for selecting forest remnants and plots

that would optimize our ability to detect incipient forest responses to spatial variation in global

change factors along urbanization gradients, while minimizing artifacts associated with remnant

size and factors other than those that simulate global change. Studying forests that meet such

criteria along urban-to-rural gradients could become an informative part of a mixed strategy of

approaches for improving forecasts of forest ecosystem change at the regional scale.

Alberti, M. (2005). "The effects of urban patterns on ecosystem function." International

Regional Science Review 28(2): 168-192.

Urban ecological systems are characterized by complex interactions among social,

economic, institutional, and environmental variables. These interactions generate complex

human-dominated landscapes, which significantly influence the functioning of local and global

earth ecosystems and the services they provide to humans and other life on earth. Urban

development fragments, isolates, and degrades natural habitats; simplifies and homogenizes

species composition; disrupts hydrological systems; and modifies energy flow, and nutrient

cycling. Urban areas also appropriate a large share of earth's carrying capacity front other regions

in terms of resource input and waste sinks. Change in ecological conditions that result from

human actions in urban areas ultimately affect human health and well-being. In this article, the

author reviews the empirical evidence on the effects that patterns of urban development have on

ecosystem function. Urban development affects the spatial heterogeneity of the landscape (i.e.,

pattern of variation in land cover) and spread of disturbance (i.e., invasive species). The author

proposes that alternative urban patterns generate differential ecological effects. The review;

reveals that the interactions between urban development patterns and ecosystem dynamics are

still poorly understood. The author draws on an empirical study of the Puget Sound metropolitan

region currently developed at the University of Washington to propose directions for future

empirical research that can inform strategies to minimize urban impacts on ecosystems.

Wessel, W. W., et al. (2004). "A qualitative ecosystem assessment for different shrublands

in western Europe under impact of climate change." Ecosystems 7(6): 662-671.

Climate change may affect the dynamics of ecosystems and the goods and services they

provide. To investigate the consequences of warming and drought for the goods and services

provided by different shrublands in various western European countries, an assessment was

carried out using results of field manipulation experiments of the CLIMOOR and VULCAN

projects. Goods and services of these shrublands mainly encompass biodiversity, various forms

of recreation, conservation of culturally and historically important landscapes, groundwater as a

drinking water source, and carbon sequestration. Warming of dry lowland heathlands in The

Netherlands and Denmark increases nutrient availability, which may lead to grass encroachment

reducing biodiversity and decreasing recreational values. Drought may reduce the chances of

grass encroachment but increase the chances of disturbances to heather vegetation. Similarly,

warming increases and drought decreases the chances of nitrate pollution to the groundwater,

which is often used as a drinking water source. Warming of the upland heathland in the UK

increases its productivity, which might enable higher grazing densities leading to improved

agricultural production. However, complex interactions between heather and invading species

may be affected. Furthermore, nitrate production is increased, which may lead to groundwater

pollution. Under drought conditions, productivity decreases and agricultural production capacity

drops. in the Mediterranean shrubland in Spain, both warming and drought led to a shift in the

species composition of seedlings and recruitment, which might lead to a change in the plant

community and a reduction in biodiversity. In the drought treatment, a decreasing soil carbon

content may lead to a loss of biodiversity, recreational possibilities, and an increased threat of

wildfires and erosion.

Sullivan, W. C., et al. (2004). "The fruit of urban nature - Vital neighborhood spaces."

Environment and Behavior 36(5): 678-700.

What makes a neighborhood space vital? This article explores the possibility that the

presence of trees and grass may be one of the key components of vital neighborhood spaces. We

report on 758 observations of individuals in 59 outdoor common spaces in a residential

development. Twenty-seven of the neighborhood common spaces were relatively green, whereas

32 were relatively barren. Results indicate that the presence of trees and grass is related to the

use of outdoor spaces, the amount of social activity that takes place within them, and the

proportion of social to nonsocial activities they support. The findings improve and broaden our

understanding of the physical characteristics that influence social contact among neighbors and

provide evidence that nature plays an important role in creating vital neighborhood spaces.

Pysek, P., et al. (2004). "Trends in species diversity and composition of urban vegetation

over three decades." Journal of Vegetation Science 15(6): 781-788.

Question: What was the change in diversity of urban synantropic vegetation in a medium-

sized Central European city during the period of increasing urbanization (1960s-1990s)?

Location: The city of Plzen, an industrial centre of the western part of the Czech Republic.

Methods: Sampling of various types of synanthropic vegetation, conducted in the 1960s, was

repeated by using the same methods in the 1990s. This yielded 959 releves, of which 623 were

made in the 1960s and 336 in the 1990s. The releves were assigned to the following

phytosociological classes: Chenopo-dietea, Artemisietea vulgaris, Galio-Urticetea, Agropyretea

repentis and Plantaginetea majoris. Total number of vascular plant species, evenness index J,

number of alien species (classified into archaeophytes and neophytes), and mean Ellenberg

indicator values for light, temperature, continentality, moisture, soil reaction, and nutrients were

obtained for each releve. Results: From 1960s to 1990s, there was a significant decrease of

species richness and diversity in synanthropic vegetation. The proportion of archaeophytes

decreased in most vegetation types, indicating the contribution of this group of species, often

confined to specific rural-like habitats, to the observed impoverishment of ruderal vegetation.

The proportion of neophytes did not change between the two periods. Comparison between

1960s and 1990s indicated a decrease in light, temperature, moisture, soil reaction and nutrient

indicator values in some vegetation types. In both periods, Artemisieta, Galio-Urticetea and

Chenopodietea formed a distinct group harbouring more species than Agropyretea and

Plantaginetea. Neophytes, i.e. recently introduced species, were most represented in the early

successional annual vegetation of Chenopodietea, rather than in perennial vegetation of the other

classes. Conclusions: Synanthropic vegetation of Plzen exhibited a general trend of decrease in

species diversity.

Powe, N. A. and K. G. Willis (2004). "Mortality and morbidity benefits of air pollution

(SO2 and PM10) absorption attributable to woodland in Britain." J Environ Manage 70.

Forests in Britain produce social and environmental benefits, in addition to marketable

timber outputs. One such non-market benefit is the reduction in air pollution, linked to health

impacts (mortality and morbidity). This study assesses the benefits of SO2 and PM10 absorption

by trees in terms of extending life expectancy of the population and reducing hospital

admissions. Working at a resolution of 1km with woodland over 2 hectares, it is estimated that,

for Britain as a whole, woodland saves between 5 and 7 deaths, that would otherwise have been

brought forward, and between 4 and 6 hospital admissions each year. The economic value of the

health effect of woodland is estimated to be at least £900,000 per year. Smaller areas of

woodland, often located closer to population, sometimes strategically planted close to pollution

sources, will generate additional air pollution absorption benefits to those estimated here.

Researching such benefits would require more detailed data than is available at present for a

national study. However, the health benefits of woodland are relatively small in comparison to

other non-market forestry benefits.

Platt, R. H. (2004). Regreening the metropolis: Pathways to more ecological cities. Urban

Biosphere and Society: Partnership of Cities. 1023: 49-61.

Eighty percent of the American population now lives in metropolitan regions whose

geographic extent continues to expand even as many core cities and inner-tier suburbs lose

middle-class populations, jobs, and tax base. Urban sprawl and the socioeconomic polarizing of

metropolitan America have been fostered by public policies including (1) federal subsidies for

new infrastructure on the urban fringe; (2) tax policies that favor home ownership over rental

properties; (3) local zoning codes; and (4) federal and state neglect of older urban

neighborhoods. In the face of diminished access to "nature" outside of metropolitan areas, locally

based efforts to protect and restore greenspaces within urban areas seek to make older

communities more habitable and more "ecological." Some pathways to more ecological cities

include the following: (1) the notion of rus in urbe ("the country in the city"); (2) the "usable

outdoors"; (3) garden cities and eco-villages; (4) green buildings and green roofs; (5) urban

biodiversity; (6) ecological services; and (7) space, nature, and place.

Nali, C., et al. (2004). "Plants as indicators of urban air pollution (ozone and trace

elements) in Pisa, Italy." Journal of Environmental Monitoring 6(7): 636-645.

A biennial integrated survey, based on the use of vascular plants for the bioindication of

the effects of tropospheric ozone, was performed in the area of Pisa (Tuscany, Central Italy). It

also investigated the distribution of selected trace elements in plants and the data were compared

with those obtained from the use of passive samplers, automatic analysers of ozone and lichen

biodiversity. Photochemically produced ozone proved to be present during the warm season,

with maximum hourly means surpassing 100 ppb: the use of supersensitive tobacco Bel-W3

confirmed the value of detailed, cost-effective, monitoring surveys. Trials with clover clones

demonstrate that sensitive plants undergo severe biomass reduction in the current ozone regime.

The mean NC-S ( clover clone sensitive to ozone): NC-R ( resistant) biomass ratio ranged from

0.7 ( in 1999) to 0.5 ( in 2000). The economic impact of these reductions deserves attention. The

data obtained using passive ozone samplers exceeded those obtained using an automatic

analyser. The mapping of epiphytic lichen biodiversity was not related to the geographical ozone

distribution as can be seen from the tobacco's response. Lettuce plants grown under standardized

conditions were used positively as bioaccumulators of trace elements: Pb was abundantly

recovered, but a large portion of this element was removed by washing.

Martin, C. A. and L. B. Stabler (2004). "Urban horticultural ecology: Interactions between

plants, people and the physical environment." Expanding Roles for Horticulture in

Improving Human Well-Being and Life Quality (639): 97-101.

Growing interest in the ecology of cities is providing a unique opportunity for

horticultural scientists to study plant processes in an environmental setting that is foreign to most

ecologists. Past studies in urban plant ecology have been limited to inventories and distribution

of the plants present or have focused on areas of remnant native vegetation and impacts of

urbanization on those remnant patches. Classic ecological pedagogy depicts exotic species as

invaders, and human manipulations of the geo-surface as disturbance events. The real essence of

urban vegetation as a system that has been carefully designed and is intensively managed to

serve human interests has been overlooked. While the concepts of human/plant interactions are

common and inherent to horticultural research, they may present a difficult obstacle to be

overcome for those trained in conventional ecological circles. In conjunction with the Central

Arizona Phoenix Long Term Ecological Research initiative, we have approached plant

ecological studies in an and urban system as an interacting triad of plants, people, and the

physical environment. People arrange and manage plants in cities for aesthetic as well as

practical purposes. Plant viability is predicated on horticultural practices, and the anthropogenic

environment in which landscape plants grow can be physiologically stressful. At the same time,

the arrangement of plants affects the biophysical environment of the city and the quality of life of

the people living there. We propose that a better understanding of urban plant ecology is attained

using a landscape horticultural perspective, one that is familiar with the interactions between

plants, people, and the physical environment. Understanding the ecology of urban plants might

lead to design and management strategies that maximize benefits associated with plants in cities

and improve human well being and quality of life.

Koh, L. P. and N. S. Sodhi (2004). "Importance of reserves, fragments, and parks for

butterfly conservation in a tropical urban landscape." Ecological Applications 14(6): 1695-

1708.

We assessed the effectiveness of forest reserves (i.e., protected old secondary and

primary forests), fragments (i.e., scattered ruderal vegetation), and urban parks (i.e., artificially

revegetated habitats) in conserving butterfly diversity in a highly urbanized tropical landscape

(i.e., Singapore), by testing the hypothesis that forest reserves have the highest butterfly species

richness among these habitats. We investigated which environmental factors (e.g., canopy cover)

affect the distribution of butterflies across the habitats; and also tested the hypothesis that

butterfly communities of different habitats have distinct ecological traits. Further, we examined

the important determinants (e.g., area) of butterfly richness in urban parks, by testing the

hypothesis that the number of potential larval host plant species occurring in the park is the best

predictor of butterfly species richness. Rarefaction analyses showed that forest reserves had the

highest number of species, number of unique species, density of species, and community

evenness among the habitats, implying that, in urban landscapes, the least human-disturbed

habitats should be given the highest conservation priority. Forest reserves and urban parks

adjoining forests collectively accounted for 91% of all butterfly species recorded in this study,

suggesting that their preservation will likely achieve maximum complementarity for effective

butterfly conservation. Ordination analyses revealed that different butterfly species responded

differently to environmental factors (e.g., canopy cover), highlighting the importance of

maintaining environmental heterogeneity for the conservation of different butterfly species.

Classification tree analysis indicated that butterfly communities of different habitats (e.g.,

forests, urban parks) have distinct ecological traits (e.g., host plant specificity), whereby urban

avoiders were 89% likely to be forest dependent and 63% likely to be monophagous, while urban

adapters were 87% likely to be cosmopolitan and 67% likely to be oligo- or polyphagous.

Regression analyses showed that the number of potential larval host plant species and isolation

from forests were important determinants of butterfly species richness in urban parks, indicating

that urban parks should be revegetated with a diversity of potential larval host plants and should

be situated as near as possible to a forest, in order to maximize their conservation value.

Haberl, H., et al. (2004). "Land use and sustainability indicators. An introduction." Land

Use Policy 21(3): 193-198.

Bioproductive land is one of the most significant natural resources. People use the land

for receiving ecological services. This leads to humans using and favouring certain species,

while competing with all other species. Land use can create diverse cultural landscapes of

outstanding aesthetic, economic and ecological value, but it may equally result in land

degradation, soil loss and impoverished ecosystems. Hence land use is shaped by processes of

society-nature interaction. These processes can detract from sustainability--in other words,

society-nature interaction may deplete the natural capital upon which the provision of ecosystem

services for humans depends. Sustainability indicators aim at monitoring key aspects of society-

nature interaction in order to generate information needed to document the current state and the

history leading up to it. Moreover, they are useful to communicate complex sustainability

problems within the scientific community, to policy-makers and the broad public. This paper

introduces a special issue that seeks to contribute to the development of sustainability indicators

that track society-nature interaction. We focus on a variety of concepts that measure socio-

economic metabolism. All the discussed approaches relate socio-economic energy and material

flows to the bioproductive area needed to support them, above all, the ecological footprint and

the human appropriation of net primary production. In addition, this special issue also analyses

the consequences of land use intensity on the diversity, naturalness and patterns of landscapes.

Gardner, J. G., et al. (2004). "Pricing Powdery-mildew-resistant Dogwoods: Simulated

Impacts on the Nursery-industry Supply Chain." HortTechnology 14(1): 114-119.

The University of Tennessee developed a flowering dogwood tree (Cornus florida) that is

resistant to powdery mildew (Microspaera pulchra). A simulated cooperative game was created

to estimate a university fee and predict the behavior of nursery growers and nursery product

retailers. The simulation suggests a university fee of $3.51, leading to an average retail price

premium for the resistant tree of $10.41. At this price level the simulation predicts that 62

percent of all retail dogwood trees sold would be powdery mildew resistant. Based on 1998 sales

of 1.475 million dogwood trees nationwide, 914,500 were predicted to be the powdery mildew

resistant varieties, resulting in $3.2 million in revenue for the university. Given this level of sales

and markup pricing, the cost of the trees will rise in subsequent stages of the distribution

channel, and revenues will increase as well. The simulation suggests nursery revenue will

increase by nearly $4 million and costs by $3.2 million, resulting in a net nursery gain of $0.8

million. Similar computations for the retail level are $9.5 million in revenue and a net increase of

$5.5 million.

Folke, C., et al. (2004). "Regime shifts, resilience, and biodiversity in ecosystem

management." Annual Review of Ecology Evolution and Systematics 35: 557-581.

We review the evidence of regime shifts in terrestrial and aquatic environments in

relation to resilience of complex adaptive ecosystems and the functional roles of biological

diversity in this context. The evidence reveals that the likelihood of regime shifts may increase

when humans reduce resilience by such actions as removing response diversity, removing whole

functional groups of species, or removing whole trophic levels; impacting on ecosystems via

emissions of waste and pollutants and climate change; and altering the magnitude, frequency,

and duration of disturbance regimes. The combined and often synergistic effects of those

pressures can make ecosystems more vulnerable to changes that previously could be absorbed.

As a consequence, ecosystems may suddenly shift from desired to less desired states in their

capacity to generate ecosystem services. Active adaptive management and governance of

resilience will be required to sustain desired ecosystem states and transform degraded

ecosystems into fundamentally new and more desirable configurations.

Chiesura, A. (2004). "The role of urban parks for the sustainable city." Landscape and

Urban Planning 68(1): 129-138.

International efforts to preserve the natural environment are mainly concerned with large,

bio-diverse and relatively untouched ecosystems or with individual animal or vegetal species,

either endangered or threatened with extinction. Much less attention is being paid to that type of

nature close to where people live and work, to small-scale green areas in cities and to their

benefits to people. Increasing empirical evidence, however, indicates that the presence of natural

areas contributes to the quality of life in many ways. Besides many environmental and ecological

services, urban nature provides important social and psychological benefits to human societies,

which enrich human life with meanings and emotions. The main concern of this paper is to

address the importance of urban nature for citizens' well being and for the sustainability of the

city they inhabit. Some results of a survey conducted among visitors of an urban park in

Amsterdam (The Netherlands) are presented and discussed. The issues investigated concern

people's motives for urban nature, the emotional dimension involved in the experience of nature

and its importance for people's general well being. Results confirm that the experience of nature

in urban environment is source of positive feelings and beneficial services, which fulfill

important immaterial and non-consumptive human needs. Implications for the sustainability of

the city will be analyzed and discussed. (C) 2003 Elsevier B.V. All rights reserved.

Chee, Y. E. (2004). "An ecological perspective on the valuation of ecosystem services."

Biological Conservation 120(4): 549-565.

Ecosystem services are the conditions and processes through which natural ecosystems

and the species that make them up, sustain and fulfil human life. Ecosystem service valuation is

being developed as a vehicle to integrate ecological understanding and economic considerations

to redress the traditional neglect of ecosystem services in policy decisions. This paper presents a

critical review on the neoclassical economic framework, tools used for economic valuation of

ecosystem services and the economic welfare approach to collective decision-making, from an

ecological perspective. The applicability of the framework and techniques for valuing ecosystem

services are evaluated in light of the challenges posed by the complex, non-linear nature of many

ecosystem services. Decisions concerning ecosystem management are often complex, socially

contentious and fraught with uncertainty. Although judicious application of economic valuation

techniques to ecosystem services can provide valuable information for conceptualizing decision

choices and evaluating management options, there are serious limitations in the economic

welfare approach to decision-making. These shortcomings and their implications for ecosystem

management are elucidated and alternative approaches that emphasize participation, explicit

treatment of uncertainty and transparent decision-making processes are discussed.

Breuste, J. H. (2004). "Decision making, planning and design for the conservation of

indigenous vegetation within urban development." Landscape and Urban Planning 68(4):

439-452.

Utilization of indigenous vegetation as parts of the urban landscape is still a problematic

matter in decision making and planning. On one hand, there are many activities in cities and

towns aimed at providing more green areas. On the other hand, there is an increasing destruction

of indigenous vegetation, not only for building purposes, but also partly by extreme maintenance

of urban open spaces and an increasing number of recreation activities. Despite there is a

considerable amount of scientific knowledge on indigenous plants in urban and sub-urban areas,

the use of this knowledge is still low. The socio-economic knowledge about such vegetation

(acceptance, utilization, economic value, etc.) is mostly non-existent in many regions. The

indigenous vegetation has to become an important aspect of urban biodiversity as well as part of

the living space of the urban dwellers. This links two important subjects: the specific nature of

the original biomes in which the urban region is situated, and the cultural aspect of acceptance of

various kinds of nature. The nature preservation strategies, especially of Central European cities,

show a lack of willingness to preserve indigenous vegetation sites. But there are instruments of

planning and methods which allow better preservation of these areas. Furthermore, it must be

determined whether it is possible to reduce the human impact on open spaces by reintroducing

indigenous vegetation, and under what circumstances this works. The cost reduction of

maintenance of urban green areas is seen as one major factor linking to this target. Human

acceptance is still an uncertain factor which has to be investigated and will, in the long term, be

improved by education and evaluated under different cultural and social aspects. The

management of the classical conflict between pure species or habitat preservation in open urban

spaces of untouched nature and the high pressure of recreation on the same sites, is explained by

example. An important question follows: will it be possible to establish "new" indigenous nature

in the urban and sub-urban spaces?

Anna, C. (2004). "The role of urban parks for the sustainable city." Landscape and Urban

Planning 68(1): 129-138.

International efforts to preserve the natural environment are mainly concerned with large,

bio-diverse and relatively untouched ecosystems or with individual animal or vegetal species,

either endangered or threatened with extinction. Much less attention is being paid to that type of

nature close to where people live and work, to small-scale green areas in cities and to their

benefits to people. Increasing empirical evidence, however, indicates that the presence of natural

areas contributes to the quality of life in many ways. Besides many environmental and ecological

services, urban nature provides important social and psychological benefits to human societies,

which enrich human life with meanings and emotions. The main concern of this paper is to

address the importance of urban nature for citizens’ well being and for the sustainability of the

city they inhabit. Some results of a survey conducted among visitors of an urban park in

Amsterdam (The Netherlands) are presented and discussed. The issues investigated concern

people’s motives for urban nature, the emotional dimension involved in the experience of nature

and its importance for people’s general well being. Results confirm that the experience of nature

in urban environment is source of positive feelings and beneficial services, which fulfill

important immaterial and non-consumptive human needs. Implications for the sustainability of

the city will be analyzed and discussed.

Turner, R. K., et al. (2003). "Valuing nature: lessons learned and future research

directions." Ecological Economics 46(3): 493-510.

This paper critically reviews the literature on environmental valuation of ecosystem

services across the range of global biomes. The main objective of this review is to assess the

policy relevance of the information encompassed by the wide range of valuation studies that

have been undertaken so far. Published and other studies now cover most ecosystems, with

aquatic and marine contexts attracting the least attention. There is also a predominance of single

function valuation studies. Studies valuing multiple functions and uses, and studies which seek to

capture the 'before and after' states as environmental changes take place, are rare. By and large it

is the latter types of analyses that are most important as aids to more rational decision taking in

ecosystem conservation versus development situations involving different stakeholders (local,

national and global). Aggregate (global scale) estimates of ecosystems value are problematic,

given the fact that only 'marginal' values are consistent with conventional decision-aiding tools

such as economic cost-benefit analysis. In general, valuation data provide prima facie support for

the hypothesis that net ecosystem service value diminishes with biodiversity and ecosystem loss

[Balmford et al. (2002), Science 297, p. 950]. Future research effort should include

complementary research on multiple ecosystem services that seeks to capture the temporal

disturbance profile and its causal factors. The explicit recognition of multiple, interdependent

ecosystem services and values, poses both conceptual and empirical research challenges. It

would serve to transform the practice of research in this sub-field via the a priori assumption of

multiple (and inter-dependent) use, instead of independent single use. This line of reasoning can

then be extended to the institutional arrangements that determine which values are captured. New

institutional processes and arrangements are probably required in order to best realise benefit

streams from multiple ecosystem use and non-use provision, across a range of different

stakeholders.

Streiling, S. and A. Matzarakis (2003). "Influence of single and small clusters of trees on

the bioclimate of a city: A case study." J Arboriculture 29.

This study examines the effects of single trees and small clusters of trees on the

bioclimate of a city. Investigations of the thermal environment and air quality of the urban

climate were carried out on September 19 and September 29, 2000, at Fahnenbergplatz, in

the northern city center of Freiburg in southwest Germany. The study area, approximately

1,700 m2, contains 12 horsechestnut trees (Aesculus, hippocastanum) of different ages and

sizes. The positive effect of trees on the thermal environment and air quality component was

confirmed by the study. In particular, the mean radiation temperature and the human

biometeorlogical thermal index known as the physiolgoical equivalent temperature showed

distinct differences between areas with trees and areas without trees, despite the small size of the

investigation area. A high reduction potential for nitrogen oxides and ozone was found inside the

tree corwns, but outside the crowns there was no measurable reduction. The most important

result regarding volatile organic compounds (VOC) was the absence of terpene emission sform

the horsechestnuts. SImilary, no isoprene emissions from the horsechestnuts. Therefore,

horsechestnut trees have a very small ozone-forming potential.

Pauleit, S. (2003). "Urban street tree plantings: indentifying the key requirements."

Proceedings of the Institution of Civil Engineers-Municipal Engineer 156(1): 43-50.

Trees fulfil important aesthetic, social and environmental functions in urban areas.

However, tree life is increasingly under stress, leading to poor vitality and tree decline,

particularly in urban streets. The requirements for healthy tree life are broadly known. Criteria

for the design of planting sites in streets, choice of tree species and maintenance requirements are

outlined in the paper. However, a European survey reveals the wide variance of tree planting and

management practice. UK cities and towns performed poorly against criteria such as level of

expenditure for trees, street tree quality and site preparation. Evidently, trees are very much

undervalued and only an afterthought in the process of planning, design and management of

streets. There is an urgent need to develop and apply comprehensive concepts for sustainable

urban forests and specifically for street tree plantings. Standards for site planning, as well as

increased knowledge of suitable tree species and tree quality standards are key to achieving this

goal. Information on best practice needs to be more widely disseminated. The European pilot

survey was a first step towards establishing an information network across Europe to collect the

information needed for this purpose. There is a need for close collaboration between civil

engineers and landscape architects from a very early stage to integrate tree plantings into the

design of streets, in order to maximise their benefits and avoid potential conflicts with traffic and

utilities.

Pataki, D. E., et al. (2003). "Seasonal cycle of carbon dioxide and its isotopic composition in

an urban atmosphere: Anthropogenic and biogenic effects." Journal of Geophysical

Research-Atmospheres 108(D23).

Atmospheric CO2 mixing ratios and carbon and oxygen isotope composition were

measured at 18 m above the ground in Salt Lake City, Utah, United States, for a one-year period.

Mixing ratios were highest in the wintertime with maximum values approaching 600 mmol mol(-

1) during atmospheric inversions. Nighttime carbon and oxygen isotope ratios of source CO2

showed a seasonal pattern with isotopically depleted values in the wintertime and isotopically

enriched values in the spring and summer. The effects of gasoline combustion, natural gas

combustion, and biogenic respiration of plants and soils on CO2 mixing ratio were quantified

with a mass balance calculation using dual carbon and oxygen isotopic tracers. The calculations

showed large contributions of natural gas combustion in the winter and significant nighttime

biogenic respiration in the spring and late summer/early fall. The isotope-tracer technique used

shows promise for quantifying the impacts of urban processes on the isotopic composition of the

atmosphere and partitioning urban CO2 sources into their component parts.

Parr, T. W., et al. (2003). "Detecting environmental change: science and society -

perspectives on long-term research and monitoring in the 21st century." Science of The

Total Environment 310(1-3): 1-8.

Widespread concern over the state of the environment and the impacts of anthropogenic

activities on ecosystem services and functions has highlighted the need for high-quality, long-

term datasets for detecting and understanding environmental change. In July 2001, an

international conference reviewed progress in the field of long-term ecosystem research and

monitoring (LTERM). Examples are given which demonstrate the need for long-term

environmental monitoring and research, for palaeoecological reconstructions of past

environments and for applied use of historical records that inform us of past environmental

conditions. LTERM approaches are needed to provide measures of baseline conditions and for

informing decisions on ecosystem management and environmental policy formulation. They are

also valuable in aiding the understanding of the processes of environmental change, including the

integrated effects of natural and anthropogenic drivers and pressures, recovery from stress and

resilience of species, populations, communities and ecosystems. The authors argue that, in order

to realise the full potential of LTERM approaches, progress must be made in four key areas: (i)

increase the number, variety and scope of LTERM activities to help define the operational range

of ecosystems; (ii) greater integration of research, monitoring, modelling, palaeoecological

reconstruction and remote sensing to create a broad-scale early warning system of environmental

change; (iii) development of inter-disciplinary approaches which draw upon social and

environmental science expertise to understand the factors determining the vulnerability and

resilience of the nature-society system to change; and (iv) more and better use of LTERM data

and information to inform the public and policymakers and to provide guidance on sustainable

development.

Ormerod, S. J. (2003). "Restoration in applied ecology: editor's introduction." Journal of

Applied Ecology 40(1): 44-50.

1. The need to rehabilitate and restore ecological resources degraded by overuse was

already established when the Journal of Applied Ecology was launched in 1964. In the

intervening 40 years, submissions on restoration have increased and now contribute at least 8-

12% of the papers published annually. Examples from subjects such as conservation biology,

pollution ecology and ecological modelling show that notions of restoration or recovery are now

implicit in the philosophy of applied ecology. 2. The terminology of restoration ecology is

increasingly clear, but there is still debate about the definition of restoration end-points.

Although restoration constitutes the process of assisting recovery, success ultimately depends on

whether populations, communities and ecological functions attain limits typical of un-degraded

reference systems. With evidence increasing that the removal of stressors is not always sufficient

to guarantee restoration success, the true arbiters will be the organisms and processes at which

restoration is aimed. Stringent appraisal on these ecological criteria will be required if restored

systems are to conserve biodiversity and deliver ecosystem services to the extent that many

restoration ecologists believe is possible. 3. Botanical systems have figured most prominently

among the Journal's restoration papers, but there is increasing emphasis on the restoration of

individual populations or species, often invertebrates or vertebrates such as birds. 4. Recent

contributions on restoration to the Journal of Applied Ecology include projects seeking the ideal

technical solutions to specific restoration problems. Other papers are distinguished for their

seminal value and often show that intervention is preferable to natural succession in delivering a

successful outcome. Examples range from species and ecosystem-level restoration to real

evidence that large-scale restoration can be achieved by policy instruments such as agri-

environment. Papers published in the Journal also show how restoration can bring ecological

value to urban locations, where many people now gain their first-ever wildlife experiences. 5.

Synthesis and applications. This special profile of five papers follows these themes in developing

the assessment of restoration end-points, in understanding the restoration process, and in

identifying factors that promote success or bring failure. Restoration ecology offers yet another

example where the application of ecology simultaneously provides academic leadership and

solutions to real environmental problems. In an era in which the adverse economic and

ecological consequences of environmental degradation are increasingly unacceptable, restoration

ecology is emerging as one of the most important disciplines in the whole of environmental

science.

Okuda, M. (2003). "Epidemiology of Japanese cedar pollinosis throughout Japan." Ann

Allergy Asthma Immunol 91.

Background: Japanese cedar pollinosis (JCP) is a common disease posing a major public

health problem in Japan. For health care policy planning and development of new treatment

modalities, investigation of the accurate prevalence and current status of JCP nationwide is

imperative.

Objective: To ascertain the prevalence and the current status of JCP in Japan with use of

a cross-sectional random sampling method.

Methods: In a nationwide survey conducted shortly after the peak pollen season, self-evaluation

questionnaire were mailed to 10,920 subjects from 390 of 3,370 places in 12 regions in Japan.

Results: The response rate was 53.7%, and the usable response rate was 51.5%. The age-

adjusted prevalence was 19.4%; the estimated prevalence was 13.1% after adjustment for

misdiagnosis, incorrect answers, response rate, and case mix. JCP was most prevalent in the

Kanto, Tokai, and Kinki areas and in working adults rather than in children or subjects ages 60 to

79 years. Total pollen count during the pollen season correlated well with the prevalence of JCP

in individual regions. In subjects with JCP, nasal symptom were more severe than eye

symptoms, 62.5% had severe or moderate interference with daily activities and consulted

physicians, 54.1% took prescribed drugs, and 82% used some method to avoid pollen.

Conclusions: The age-adjusted prevalence of JCP was 19.4% of the Japanese population,

and estimated prevalence after correction of possible biases was 13.1%. Prescribed drugs treated

approximately 60% of subjects with JCP, and 80% of subjects tried self-care by avoiding pollen.

McPherson, E. G. (2003). "Urban forestry - The final frontier?" Journal of Forestry

101(3): 20-25.

Forestry and urban forestry have more in common than practitioners in either field may

think. The two disciplines could each take better advantage of the other's expertise, such as

foresters' impressive range of scientific theory and technological sophistication, and urban

foresters' experience in working with diverse stakeholders in the public arena. The wildland-

urban interface is geographic center of convergence, and the nexus of forest ecology and human

ecology will become forestry's next frontier-where forestry and urban forestry join together to

construct healthier habitats for humans.

Maco, S. E. and E. G. McPherson (2003). "A practical approach to assessing structure,

function and value of street tree population in small communities." Journal of

Aboriculture 29(2): 84-97.

This study demonstrates an approach to quantify the structure, benefits, and costs of

street tree populations in resource-limited communities without tree inventories. Using the city

of Davis, California, U.S., as a model, existing data on the benefits and costs of municipal trees

were applied to the results of a sample inventory of the city’s public and private street trees.

Results indicate that Davis maintained nearly 24,000 public street trees that provided $1.2

million in net annual environmental and property value benefits, with a benefit–cost ratio of

3.8:1. The city can improve long-term stability of this resource by managing maintenance, new

plantings, and stand rejuvenation on a city zone basis.

Maco, S. E. and E. G. McPherson (2003). "A practical approach to assessing structure,

function, and value of street tree populations in small communities." J Arboriculture 29.

This study demonstrates an approach to quantify the structure, benefits, and costs of

street tree populations in resource-limited communities without tree inventories. Using the city

of Davis, California, U.S., as a model, existing data on the benefits and costs of municipal trees

were applied to the results of a sample inventory of the city’s public and private street trees.

Results indicate that Davis maintained nearly 24,000 public street trees that provided $1.2

million in net annual environmental and property value benefits, with a benefit–cost ratio of

3.8:1. The city can improve long-term stability of this resource by managing maintenance, new

plantings, and stand rejuvenation on city zone basis.

Lichtfouse, E., et al. (2003). "delta C-13 values of grasses as a novel indicator of pollution

by fossil-fuel-derived greenhouse gas CO2 in urban areas." Environmental Science &

Technology 37(1): 87-89.

A novel fossil fuel pollution indicator based on the C-13/C-12 isotopic composition of

plants has been designed. This bioindicator is a promising tool for future mapping of the

sequestration of fossil fuel CO2 into urban vegetation. Theoretically, plants growing in fossil-

fuel-CO2-contaminated areas, such as major cities, industrial centers, and highway borders,

should assimilate a mixture of global atmospheric CO2 of delta(13)C value of -8.02parts per

thousand and of fossil fuel CO2 of average delta(13)C value of -27.28parts per thousand. This

isotopic difference should, thus, be recorded in plant carbon. Indeed, this study reveals that

grasses growing near a major highway in Paris, France, have strikingly depleted delta(13)C

values, averaging at -35.08parts per thousand, versus rural grasses that show an average

delta(13)C value of -30.59parts per thousand. A simple mixing model was used to calculate the

contributions of fossil-fuel-derived CO2 to the plant tissue. Calculation based on contaminated

and noncontaminated isotopic end members shows that urban grasses assimilate up to 29.1% of

fossil-fuel-CO2-derived carbon in their tissues. The C-13 isotopic composition of grasses thus

represents a promising new tool for the study of the impact of fossil fuel CO2 in major cities.

Konijnendijk, C. C. (2003). "A decade of urban forestry in Europe." Forest Policy and

Economics 5(2): 173-186.

Major changes in society have led to a call for structural changes in forestry, also in

Europe. Urbanisation as one of the major driving forces has had a clear impact on European

forestry. One of the new approaches emerging in response is the concept of urban forestry. It was

developed in North America during the 1960s as innovative approach to managing natural

resources in urban environments. Aimed at the integrated planning and management of all tree-

based resources in cities and towns, the concept found broad support in North America after

initial resistance from both foresters and urban green professionals. Similar resistance was met in

Europe, and here it took until the early 1990s before the concept of urban forestry found broader

acceptance and support. Since then, a European urban forestry research community has emerged,

as have policies, programmes and higher education incorporating elements of urban forestry.

Urban forest resources in Europe might be small in relative terms compared to other natural

resources. They do, however, cover millions of hectares of land and provide multiple, highly

demanded goods and services. Forestry can benefit from urban forestry experiences and

innovations, for example in terms of better meeting the expectations and demands of urban

society. Urban forestry, on the other hand, is firmly rooted in some of the basic concepts of

traditional forestry, such as sustained yield. Review of a decade of urban forestry in Europe

shows that strong links should be maintained for the benefit of both.

Hare, M., et al. (2003). "Participatory modelling in natural resource management: a

comparison of four case studies." Integrated Assessment 4(2): 62-72.

The need to understand what might constitute best practice in participatory methods for

resource management is becoming ever more important as the requirement for a high level of

participation becomes prescribed in the environmental directives of the EU and elsewhere. Since

there are numerous potential stakeholders who may participate, various different goals of

participation and many potential participatory methods designed to achieve them, there is a need

for better understanding of how the methods can be practicably applied to particular stakeholders

and for what purpose. As input into this process, this paper presents an overview of four natural

resource management projects carried out using participatory modelling methods involving

stakeholders in the co-design and social learning of management solutions. From these case

studies, a description is elicited of the different types of participatory process structures adopted,

as well as an analysis of the influences behind the selection of stakeholders and their level of

involvement. Six influences in the design of such structures are identified and illustrated with

examples: project goals, democratic participatory goals, existing power structures, stakeholder

numbers, researchers' normative beliefs and the scale at which decisions need to be supported.

These influences place limits on the freedom of practitioners to develop the type of processes

they might otherwise intend. Classification of the process structures according to the level of

involvement of stakeholders and their scale of action leads to a discussion about a particular

problem of co-design processes: a scale of action mismatch. That is, some process structures, due

to the influences mentioned above, end up not involving all the necessary decision makers in the

co-design of management solutions. As a result, there has to be additional methods employed to

ensure that the results of co-design, i.e. a set of management options, can be passed on to and

adopted by excluded decision makers. The paper concludes by briefly looking at examples of

possible methods, such as process extensions, e.g., consultation meetings and information

campaigns, and the adoption of institutional safeguards.

Hare, M., et al. (2003). "Participatory modelling in natural resource management: a

comparison of four case studies." Integr Assess 4.

The need to understand what might constitute best practice in participatory methods for

resource management is becoming ever more important as the requirement for a high level of

participation becomes prescribed in the environmental directives of the EU and elsewhere. Since

there are numerous potential stakeholders who may participate, various different goals of

participation and many potential participatory methods designed to achieve them, there is a need

for better understanding of how the methods can be practicably applied to particular stakeholders

and for what purpose. As input into this process, this paper presents an overview of four natural

resource management projects carried out using participatory modelling methods involving

stakeholders in the co-design and social learning of management solutions. From these case

studies, a description is elicited of the different types of participatory process structures adopted,

as well as an analysis of the influences behind the selection of stakeholders and their level of

involvement. Six influences in the design of such structures are identified and illustrated with

examples: project goals, democratic participatory goals, existing power structures, stakeholder

numbers, researchers’ normative beliefs and the scale at which decisions need to be supported.

These influences place limits on the freedom of practitioners to develop the type of processes

they might otherwise intend.

Classification of the process structures according to the level of involvement of

stakeholders and their scale of action leads to a discussion about a particular problem of co-

design processes: a scale of action mismatch. That is, some process structures, due to the

influences mentioned above, end up not involving all the necessary decision makers in the co-

design of management solutions. As a result, there has to be additional methods employed to

ensure that the results of co-design, i.e. a set of management options, can be passed on to and

adopted by excluded decision makers. The paper concludes by briefly looking at examples of

possible methods, such as process extensions, e.g., consultation meetings and information

campaigns, and the adoption of institutional safeguards.

Godefroid, S. and N. Koedam (2003). "Distribution pattern of the flora in a peri-urban

forest: an effect of the city-forest ecotone." Landscape and Urban Planning 65(4): 169-185.

We studied the spatial variation of plant assemblages in a 4383 ha deciduous forest in the

periphery of Brussels. All vascular plant species were recorded following a grid-map of I km(2)-

cells totally or partly covered by the forest. A total of 414 plant species was observed. Species

composition and plant functional groups in forest edges and the neighbouring forest interior are

studied. The study quantifies plant functional groups (e.g. ancient forest plants, true forest

species, rare species, geophytes, C, S or R-strategists) in the plots and tests for relationships with

the geographical position in the forest according to a city-to-forest gradient. Our results led us to

identify distinct characteristics of forest flora based on the distance to the actual city border. The

study revealed significant outer edge effects on the flora. Plant composition of the forest interior

and forest edge can be separated by ordination on species composition, suggesting that these two

biotopes have a distinct species assemblage. chi(2)-test and Two-Way-Indicator-Species-

Analysis detected significant edge-associated species that were recorded exclusively in the edge

or were the most frequent in the forest edge. We found that forest stands close to urban areas

support populations of indicators of disturbance (pioneer species, C and R-strategists and aliens)

to plots which are distant from the city. However, our observations also suggest that species

groups with high conservation value (e.g. ancient forest species, or rare species) may also be

more represented at the edge than in the core of the forest. Moreover, no forest specialists which

would occur only in the interior zone were found. These observations are in disagreement with

the hypothesis that true forest plants and species groups of high conservation value would be

more frequent in the forest than on the borders. These findings are applicable to the management

of forests in an urban context. (C) 2003 Elsevier Science B.V. All rights reserved.

Godefroid, S. and N. Koedam (2003). "How important are large vs. small forest remnants

for the conservation of the woodland flora in an urban context?" Global Ecology and

Biogeography 12(4): 287-298.

To test whether, in an urban area, small forest fragments are more important than large

ones, the present study aimed at firstly exploring the relationship between plant functional

groups or individual species and urban woodlot characteristics such as patch area and isolation,

and secondly investigating whether equal-sized combinations of islands tend to differ in species

richness. Location The city of Brussels. Methods We considered the relationship between size,

species richness and plant functional groups among one very large (1666 ha) and 11 rather small

(2-123 ha) woodlots. Results The largest woodlot harboured species missing in the smaller ones.

The species-area relationship plotted for these wooded patches fitted the semilog model very

well. Twenty-three species had a significantly higher frequency in the main forest. Only six

species had a significantly higher frequency in smaller woodlots. The occurrence of species

groups with high conservation value (e.g. ancient forest species, rare species) was higher in large

patches. However, a SLOSS analysis showed that habitat subdivision appeared to be associated

with increased species counts. A marginally nonsignificant effect of distance to the main forest

became significant when matrix species were removed from the patch samples. Conclusions

Although overall the data showed a higher conservation value for large woods, some plant

functional groups (e.g. woodland species vs. ancient forest species) responded differently to

fragmentation. This illustrates that, for conservation strategies, studies considering the biotic

characteristics of remnants should focus on the species number of particular plant functional

groups, especially those with high conservation value. Furthermore, matrix species should be

removed from the analysis in order not to mask underlying patch size and distance effects.

Godefroid, S. and N. Koedam (2003). "Identifying indicator plant species of habitat quality

and invasibility as a guide for peri-urban forest management." Biodiversity and

Conservation 12(8): 1699-1713.

A floristic survey has been carried out in a periurban forest, the Sonian Forest in

Brussels, to identify indicator plant species in the herbaceous layer, which could be used as an

aid within the framework of a more sustainable management of the forest. Three hundred and

seventy two (372) taxa have been identified, 33 of which are non-native (i.e. non-indigenous

species regarding the study area, whether invasive or not). Criteria of habitat quality that have

been chosen are the species richness, the commonness of the habitat, based on constitutive

species, and its invasibility (vulnerability for invasion). On the basis of a comparison of the value

of these criteria when each considered (potential indicator) species is present or not, 17 species

have been recognised as reliable indicators of at least one of these three criteria. In particular,

vegetation types containing either Anthriscus sylvestris, Galeopsis tetrahit or Senecio ovatus

were found to be more susceptible to invasion than other habitats. The way to how the

predictability of invasions might be effectively used as a management tool is discussed.

Furthermore, we found a positive significant correlation (Bonferroni corrected probabilities)

between the species richness and luminosity factor (derived from Ellenberg's indices), and the

proportion of grassland and wetland species. The species richness was significantly negatively

correlated with the proportion of woodland species. An increase in commonness was

significantly correlated with a decrease in the proportion of geophytes. The usefulness of these

results as an ecological basis for forest management is discussed.

Chocholouskova, Z. and P. Pysek (2003). "Changes in composition and structure of urban

flora over 120 years: a case study of the city of Plzen." Flora 198(5): 366-376.

Floristic lists of the industrial city of Plzen, W Bohemia, Czech Republic, were compiled

for the periods 1880-1910, 1960s and 1990s. Data were obtained for the city and its surroundings

and abundance of each species was estimated from primary literature and recent field research.

Changes in species richness on the time scale of 120 years were described, and dynamics of

representation of alien species was analysed. Total number of species recorded decreased from

1173 in 1880-1910 to 988 in 1960s to 1043 in 1990s. These dynamics differed between city and

surroundings. In the city, species number was gradually increasing while the trend was opposite

in the surroundings. When expressed per to,, area, initial pattern of higher species richness in the

surroundings was reversed in the course of the study period. The floristic similarity between

1880-1910 and 1990s was 0.57 for the surroundings and 0.41 for the city. In the 120 years

covered, 805 species remained permanently present, 368 disappeared and 238 immigrated as

new. Proportional representation of common species decreased and that of rare species increased.

The representation of neophytes in the total flora of the study area increased from 6.2% in 1880-

1910 to 13.2% in 1960s to 17.0% in 1990s. The proportion of native species decreased

accordingly, and that of archaeophytes was stable over the study period. The representation of

woody plants increased in the city, namely among neophytes. Over the study period, there was

an increase in the representation of C and CR-strategists, mainly on behalf of CSR and SR

strategists. CSR and CS strategies are most typical of native flora elements, C and CR of

neophytes, while R and CR are most represented among archaeophytes. No consistent temporal

trends in indicator values were recorded but the flora of the city differed from that of the

surroundings in higher demands for light, temperature, nitrogen and soil reaction and lower

demands for moisture. The present paper demonstrates that historical data on urban floras

provide a powerful tool to evaluate the effect of humans on the development of urban landscapes

and their plant life.

Bjorheden, R., et al. (2003). "Systems analyses for harvesting small trees for forest fuel in

urban forestry." Biomass & Bioenergy 24(4-5): 389-400.

Forests in urban areas are important for recreation. Social, aesthetic and recreational

values are at least as important for forest management as economy and conventional forestry

considerations. Systems with short, intensive harvesting phases and limited damage to ground

and trees are also advantageous, in order to reduce disturbance through harvesting operations.

Further, slash free stands constitute a more attractive environment for recreational activities.

Forest fuel harvesting may provide these conditions. This study analyses the economic feasibility

of harvesting forest fuel in dense, small diameter stands. The analyses are performed as

simulated treatments in selected stand types. Both existing and non-existing forest fuel systems

are tested. Conventional cleaning and conventional thinning for pulpwood are included as

reference systems. The average dbh of removed trees varied between 3.0 and 10.5 cm. The

potential yield of biomass in the studied stand types is high-under Swedish conditions over 35

tonnes dry substance per ha. Harvesting pulpwood exclusively means that only a small portion of

the potential is utilised. Forest fuel systems based on motor-manual work are the most

competitive in the smallest diameter stands. They break even from dbh similar to4.5 cm in birch

stands and from similar to5.5 cm in pine. Simulated systems include a feller-chipper-forwarder

and a two-machine system with a feller-bundler and a forwarder. Both are suitable for larger tree

sizes than the manual methods. The conventional pulpwood method shows the poorest result, but

start competing with the poorest forest-fuel systems from dbh similar to10 cm (removed trees).

Xiao, Q. and E. G. McPherson (2002). "Rainfall interception by Santa Monica's municipal

urban forest." Urban Ecosystems 6(4): 291-302.

Effects of urban forests on rainfall interception and runoff reduction have been

conceptualized, but not well quantified. In this study rainfall interception by street and park trees

in Santa Monica, California is simulated. A mass and energy balance rainfall interception model

is used to simulate rainfall interception processes (e.g., gross precipitation, free throughfall,

canopy drip, stemflow, and evaporation). Annual rainfall interception by the 29,299 street and

park trees was 193,168 m3 (6.6 m3/tree), or 1.6% of total precipitation. The annual value of

avoided stormwater treatment and flood control costs associated with reduced runoff was

$110,890 ($3.60/tree). Interception rate varied with tree species and sizes. Rainfall interception

ranged from 15.3% (0.8 m3/tree) for a small Jacaranda mimosifolia (3.5 cm diameter at breast

height) to 66.5% (20.8 m3/tree) for a mature Tristania conferta (38.1 cm). In a 25-year storm,

interception by all street and park trees was 12,139.5 m3 (0.4%), each tree yielding $0.60 (0.4

m3/tree) in avoided flood control costs. Rainfall interception varied seasonally, averaging 14.8%

during a 21.7 mm winter storm and 79.5% during a 20.3 mm summer storm for a large,

deciduous Platanus acerifolia tree. Effects of differences in temporal precipitation patterns, tree

population traits, and pruning practices on interception in Santa Monica, Modesto, and

Sacramento, California are described.

Shepherd, J. M., et al. (2002). "Rainfall modification by major urban areas: Observations

from spaceborne rain radar on the TRMM satellite." Journal of Applied Meteorology

41(7): 689-701.

Data from the Tropical Rainfall Measuring Mission (TRMM) satellite's precipitation

radar (PR) were employed to identify warm-season rainfall (1998-2000) patterns around Atlanta,

Georgia; Montgomery, Alabama; Nashville, Tennessee; and San Antonio, Waco, and Dallas,

Texas. Results reveal an average increase of about 28% in monthly rainfall rates within 30-60

km downwind of the metropolis, with a modest increase of 5.6% over the metropolis. Portions of

the downwind area exhibit increases as high as 51%. The percentage changes are relative to an

upwind control area. It was also found that maximum rainfall rates in the downwind impact area

exceeded the mean value in the upwind control area by 48%-116%. The maximum value was

generally found at an average distance of 39 km from the edge of the urban center or 64 km from

the center of the city. Results are consistent with the Metropolitan Meteorological Experiment

(METROMEX) studies of St. Louis, Missouri, almost two decades ago and with more recent

studies near Atlanta. The study establishes the possibility of utilizing satellite-based rainfall

estimates for examining rainfall modification by urban areas on global scales and over longer

time periods. Such research has implications for weather forecasting, urban planning, water

resource management, and understanding human impact on the environment and climate.

Shashua-Bar, L. and M. E. Hoffman (2002). "The Green CTTC model for predicting the

air temperature in small urban wooded sites." Building and Environment 37(12): 1279-

1288.

An analytical model, the Green CTTC (cluster thermal time constant) model, for

predicting diurnal air temperature inside an urban wooded site, is the object of this study. The

proposed model is based on the same principles as the CTTC model, developed earlier by M.E.

Hoffman and colleagues, with the addition of vegetation effects. It is shown that the tree thermal

effect can be evaluated either as the shade effect partly offset by the convection component of

the tree radiation balance or, equivalently, as the combined effect of evapotranspiration and the

change in the plant heat storage. In this paper, the former approach is adopted. Simulations for

testing the validity of the Green CTTC model were carried out on summer data of 11 small urban

wooded sites in the Tel-Aviv metropolitan area near the Mediterranean sea coast. Results show a

satisfactory fit, with average root-mean-square-error < 0.5 K for all studied sites and time

intervals at 09:00, 15:00, and 18:00 h (summer time). The CTTC values and the convection

parameters were estimated from the empirical data, using a novel procedure. The proposed

model, which can be enlarged to encompass the cases of groves and lawns, is an appropriate tool

for assessment of the climatic impact of trees and other greeneries on urban design alternatives.

Orlinski, R. (2002). "Multipoint moss passive samplers assessment of urban airborne

polycyclic aromatic hydrocarbons: concentrations profile and distribution along Warsaw

main streets." Chemosphere 48(2): 181-186.

Polycyclic aromatic hydrocarbons (PAHs) distribution along 28 km of Warsaw main

street have been surveyed in July 2000 using moss passive samplers as a simple and economic

surrogate of direct air sampling. Altogether 74 samplers at 39 crossroads with traffic lights were

placed on the lamp post approximate to3.5 m above ground. PAHs levels determined in samplers

are in range from 828 to 3573 ng/g moss dry weight. The spatial spread of pollution within this

range is statistically close to normal distribution with mean value of 2332 ng/g. Variability

within and between study areas are rationalized in terms of urban environmental factors. PAHs

concentrations profiles across the town have appeared uniform. The dominant compounds are

phenantrene, fluoranthene and pyrene. Their contribution is 49-68% of total PAHs burden.

Nowak, D. J. and D. E. Crane (2002). "Carbon storage and sequestration by urban trees in

the USA." Environmental Pollution 116(3): 381-389.

Based on field data from 10 USA cities and national urban tree cover data, it is estimated

that urban trees in the coterminous USA currently store 700 million tonnes of carbon ($14,300

million value) with a gross carbon sequestration rate of 22.8 million tC/yr ($460 million/year).

Carbon storage within cities ranges from 1.2 million tC in New York, NY, to 19,300 tC in Jersey

City, NJ. Regions with the greatest proportion of urban land are the Northeast (8.5%) and the

southeast (7.1%). Urban forests in the north central, northeast, south central and southeast

regions of the USA store and sequester the most carbon, with average carbon storage per hectare

greatest in southeast, north central, northeast and Pacific northwest regions, respectively. The

national average urban forest carbon storage density is 25.1 tC/ha, compared with 53.5 tC/ha in

forest stands. These data can be used to help assess the actual and potential role of urban forests

in reducing atmospheric carbon dioxide, a dominant greenhouse gas.

Nowak, D. J. (2002). "The effects of urban trees on air quality." USDA Forest Service: 96-

102.

Urban vegetation can directly and indirectly affect local and regional air quality by

altering the urban atmospheric environment. The four main ways that urban trees affect air

quality area:

Temperature reduction and other microclimatic effects

Removal of air pollutants

Emission of volatile organic compounds and tree maintenance emissions Energy effects

on buildings

McPherson, E. G. and J. R. Simpson (2002). "A comparison of municipal forest benefits

and costs in Modesto and Santa Monica, California, USA." Urban Forestry & Urban

Greening 1(2): 61-74.

This paper presents a comparison of the structure, function, and value of street and park

tree populations in two California cities. Trees provided net annual benefits valued at $2.2

million in Modesto and $805,732 in Santa Monica. Benefit-cost ratios were 1.85:1 and 1.52:1 in

Modesto and Santa Monica, respectively. Residents received $1.85 and $1.52 in annual benefits

for every $1 invested in management. Aesthetic and other benefits accounted for 50% to 80% of

total annual benefits, while expenditures for pruning accounted for about 50% of total annual

costs. Although these results were similar, benefits and costs were distributed quite differently in

each city. Variations in tree sizes and growth rates, foliation characteristics, prices, residential

property values, and climate were chiefly responsible for different benefits and costs calculated

on a per tree basis.

De Groot, R. S., et al. (2002). "A typology for the classification, description and valuation of

ecosystem functions, goods and services." Ecological Economics 41(3): 393-408.

An increasing amount of information is being collected on the ecological and socio-

economic value of goods and services provided by natural and semi-natural ecosystems.

However, much of this information appears scattered throughout a disciplinary academic

literature, unpublished government agency reports, and across the World Wide Web. In addition,

data on ecosystem goods and services often appears at incompatible scales of analysis and is

classified differently by different authors. In order to make comparative ecological economic

analysis possible, a standardized framework for the comprehensive assessment of ecosystem

functions, goods and services is needed. In response to this challenge, this paper presents a

conceptual framework and typology for describing, classifying and valuing ecosystem functions,

goods and services in a clear and consistent manner. In the following analysis, a classification is

given for the fullest possible range of 23 ecosystem functions that provide a much larger number

of goods and services. In the second part of the paper, a checklist and matrix is provided, linking

these ecosystem functions to the main ecological, socio-cultural and economic valuation

methods.

Stefanov, W. L., et al. (2001). "Monitoring urban land cover change: An expert system

approach to land cover classification of semiarid to arid urban centers." Remote Sensing of

Environment 77(2): 173-185.

The spatial and temporal distribution of land cover is a fundamental dataset for urban

ecological research. An expert (or hypothesis testing) system has been used with Landsat

Thematic Mapper (TM) data to derive a land cover classification for the semiarid Phoenix

metropolitan portion of the Central Arizona-Phoenix Long Term Ecological Research (CAP

LTER) site. Expert systems allow for the integration of remotely sensed data with other sources

of georeferenced information such as land use data, spatial texture, and digital elevation models

(DEMs) to obtain greater classification accuracy. Logical decision rules are used with the various

datasets to assign class values to each pixel. TM reflectance data acquired in 1998 [visible to

shortwave infrared (VSWIR) bands plus a vegetation index] were initially classified for land

cover using a maximum likelihood decision rule. In addition, spatial texture of the TM data was

calculated. An expert system was constructed to perform post classification sorting of the initial

land cover classification using additional spatial datasets such as texture, land use, water rights,

city boundaries, and Native American reservation boundaries. Pixels were reclassified using

logical decision rules into 12 classes. The overall accuracy of this technique was 85%. Individual

class user's accuracy ranged from 73% to 99%, with the exception of the commercial/industrial

materials class. This class performed poorly (user's accuracy of 49%) due to the similarity of

subpixel components with other classes. The results presented here indicate that the expert

system approach will be useful both for ongoing CAP LTER research, as well as the planned

global Urban Environmental Monitoring (UEM) program of the Advanced Spaceborne Thermal

Emission and Reflection Radiometer (ASTER) instrument.

Sorace, A. (2001). "Value to wildlife of urban-agricultural parks: A case study from Rome

urban area." Environmental Management 28(4): 547-560.

Urban-agricultural parks could have some advantages to wildlife because of less

intensive agricultural procedures, absence of hunting pressure, and reduced human disturbance.

In this study, the breeding and wintering bird communities and the small mammal community in

an urban-agricultural park of Rome were compared to those of a close urban park and a close

agricultural, area just outside the city, The aim was to assess the best destination and

management of wildlife in natural areas at the urban-rural interface, Richness and diversity of

bird communities were higher in the urban-agricultural park. Due to habitat features and

probably human disturbances, but not to urbanization, predation, and competition factors, the

urban park drastically reduces the abundance of decreasing open-land bird species. Abundance

of these species was not significantly different in the urban-agricultural park and in the

agricultural area. In the urban-agricultural and urban park, bird and mammal pest species were

more abundant than they were in the agricultural area. Regarding decreasing abundance of small

mammal species, no significant difference among the study areas was observed. Urban-

agricultural park is a better choice than urban park for wildlife. Thus, a higher number of

preserved urban natural areas should be devoted to urban-agricultural parks. However, to

increase the abundance of open-land species and in general wildlife, a less intensive management

of cultivated and pasture patches is necessary.

Porter, E., et al. (2001). "Woody vegetation and canopy fragmentation along a forest-to-

urban gradient." Urban Ecosystems 5(2): 131-151.

To identify patterns that can be used to predict vegetation and landscape characteristics in

urban environments, we surveyed the species composition and size of woody plants, as well as

the landscape structure of forest canopies, along a forest-to-urban gradient near Oxford, Ohio,

USA. The gradient included six sites of increasingly urban land-use: a preserve, a recreational

area, a golf course, a residential subdivision, apartment complexes, and a business district. We

recorded species identity and stem diameter for all woody plants greater than 3 cm diameter at

breast height (DBH) to examine the distribution of individual species as well as overall

community composition. We used digitized aerial photographs to compare the spatial

characteristics of the forest canopy at each site. We found predictable patterns in species

diversity (Shannon index), spatial heterogeneity in species composition (mean percent

dissimilarity), and all measures of patch fragmentation (canopy cover and patch number and

size). There were clear differences in tree density and total basal area between forested sites and

developed sites, but there was little resolution among developed sites. Species richness and

average DBH showed no clear pattern, suggesting that landscaping preference largely

determined these values. We present a modified version of an intermediate heterogeneity model

that can be used to predict diversity patterns in urban areas. We discuss probable mechanisms

that led to these patterns and the potential implications for animal communities in urban

environments.

Kreuter, U. P., et al. (2001). "Change in ecosystem service values in the San Antonio area,

Texas." Ecological Economics 39(3): 333-346.

San Antonio is one of the fastest growing metropolitan areas in the USA. Urban sprawl

may significantly impact ecosystem services and functions but such effects are difficult to

quantify and watershed-level estimates are seldom attempted. The objective of the study reported

here was to determine whether LANDSAT MSS could be used to quantify changes in land-use

and ecosystem services due to urban sprawl in Bexar County, TX, in which San Antonio is

centered. The size of six land cover categories in the summer of 1976, 1985, and 1991 were

estimated in the 141 671 ha of three watersheds in Bexar County. Coefficients published by

Costanza and co-workers in 1997 [Nature 387 (1997) 253] were used to value changes in

ecosystem services delivered by each land cover category, and a sensitivity analysis was

conducted to determine the effect of manipulating these coefficients on the estimated values.

Although we estimated that there was a 65% decrease in the area of rangeland and a 29%

increase in the area of urbanized land use between 1976 and 1991, there appeared to be only a

4% net decline in the estimated annual value of ecosystem services in the study area (i.e. $5.58

ha(-1) per year, with a 15-year cumulative total value of $6.24 million for the whole study area).

This relatively small decline could be attributed to the neutralizing effect of the estimated 403%

increase in the area of the woodlands, which were assigned the highest ecosystem value

coefficient. When we assumed that the shift of rangelands to woodlands produced no net change

in the value of ecosystem services per hectare, the estimated annual ecosystem service value

declined by 15.4% ($23.22 ha(-1) per year) between 1976 and 1991. When conducting time-

series studies of ecosystem services, it is important to identify parallel changes in land cover

types in order to quantify the potentially neutralizing influence of positive land cover changes on

the negative effects of urban sprawl on ecosystem services.

Khan, F. I. and S. A. Abbasi (2001). "Effective design of greenbelts using mathematical

models." J Hazard Mater 81.

Trees, shrubs, and other vegetation can absorb and assimilate certain air pollutants if the

pollutants are present within tolerable levels. This concept is being increasingly used in

developing strips of vegetation, often called ‘greenbelts’ around sources of pollution.

But several intricacies are associated with the exercise of effective and optimal designing

of greenbelts. The pattern of dispersion of air pollutants, as effected by the density of the gaseous

plume and the meteorology of the area, must be studied with great precision because these

aspects would determine the location and the geometry of the greenbelt. The species composition

in the greenbelt should confirm to the pollutants to be attenuated as to the geoclimatic conditions

of the region. Decisions on the tree heights, and the sequence of plantation of trees and other

vegetation also similarly require complex inputs.

In this paper, the authors have addressed these issues and have presented a set of

mathematical models, which may help in the rational and optimal design of greenbelts.

Jo, H. K. and E. G. McPherson (2001). "Indirect carbon reduction by residential vegetation

and planting strategies in Chicago, USA." Journal of Environmental Management 61(2):

165-177.

Concern about climate change has evoked interest in the potential for urban vegetation to

help reduce the levels of atmospheric carbon. This study applied computer simulations to try to

quantify the modifying effects of existing vegetation on the indirect reduction of atmospheric

carbon for two residential neighborhoods in north-west Chicago. The effects of shading,

evapotranspiration, and windspeed reduction were considered and were found to have decreased

carbon emissions by 3.2 to 3.9% per year for building types in study block I where tree cover

was 33%, and -0.2 to 3.8% in block 2 where free cover was 11%. This resulted in a total annual

reduction of carbon emission averaging 158.7 (+/-12.8) kg per residence in block I and 18.1 (+/-

5.4) kg per residence in block 2. Windspeed reduction greatly contributed to the decrease of

carbon emission. However, shading increased annual carbon emission from the combined change

in heating and cooling energy use due to many frees in the wrong locations, which increase

heating energy use during the winter The increase of carbon emission from shading is somewhat

specific to Chicago, due in part to the large amount of clean, nuclear-generated cooling energy

and the long heating season. In Chicago, heating energy is required for about eight months from

October to May and cooling energy is used for the remaining 4 months from June to September

If fossil fuels had been the primary source for cooling energy and the heating season had been

shorter, the shading effects on the reduction of carbon emission would be greater. Planting of

large frees close to the west wall of buildings, dense planting on the north, and avoidance of

planting on the south are recommended to maximize indirect carbon reduction by residential

vegetation, in Chicago and other mid and high-latitude cities with long heating seasons.

Jackson, R. B., et al. (2001). "Water in a changing world." Ecological Applications 11(4):

1027-1045.

Renewable fresh water comprises a tiny fraction of the global water pool but is the

foundation for life in terrestrial and freshwater ecosystems. The benefits to humans of renewable

fresh water include water for drinking, irrigation, and industrial uses, for production of fish and

waterfowl, and for such instream uses as recreation, transportation, and waste disposal. In the

coming century, climate change and a growing imbalance among freshwater supply,

consumption, and population will alter the water cycle dramatically. Many regions of the world

are already limited by the amount and quality of available water. In the next 30 yr alone,

accessible runoff is unlikely to increase more than 10%, but the earth's population is projected to

rise by approximately one-third. Unless the efficiency of water use rises, this imbalance will

reduce freshwater ecosystem services, increase the number of aquatic species facing extinction,

and further fragment wetlands, rivers, deltas, and estuaries. Based on the scientific evidence

currently available, we conclude that: (1) over half of accessible freshwater runoff globally is

already appropriated for human use; (2) more than 1 x 10(9) people currently lack access to clean

drinking water and almost 3 x 10(9) people lack basic sanitation services; (3) because the human

population will grow faster than increases in the amount of accessible fresh water, per capita

availability of fresh water will decrease in the coming century; (4) climate change will cause a

general intensification of the earth's hydrological cycle in the next 100 yr, with generally

increased precipitation, evapotranspiration, and occurrence of storms, and significant changes in

biogeochemical processes influencing water quality; (5) at least 90% of total water discharge

from U.S. rivers is strongly affected by channel fragmentation from dams, reservoirs, interbasin

diversions, and irrigation; and (6) globally, 20% of freshwater fish species are threatened or

extinct, and freshwater species make up 47% of all animals federally endangered in the United

States. The growing demands on freshwater resources create an urgent need to link research with

improved water management. Better monitoring, assessment, and forecasting of water resources

will help to allocate water more efficiently among competing needs, Currently in the United

States, at least six federal departments and 20 agencies share responsibilities for various aspects

of the hydrologic cycle. Coordination by a single panel with members drawn from each

department, or by a central agency, would acknowledge the diverse pressures on freshwater

systems and could lead to the development of a well-coordinated national plan.

Hamerlynck, E. P. (2001). "Chlorophyll fluorescence and photosynthetic gas exchange

responses to irradiance of Tree of Heaven (Ailanthus altissima) in contrasting urban

environments." Photosynthetica 39(1): 79-86.

Sun-and shade-adapted plants of Ailanthus altissima utilized thermal-dissipative

photoprotection (NPQ) across a range of photosynthetic photon flux densities (PPFD), with

higher NPQ and lower maximum quantum yield of photosystem 2 photochemistry (F-v/F-m) in

sun-adapted individuals, suggesting increased engagement of antennae-based quenching.

Photosynthetic quantum requirements (Q(req); number of photons per CO2) were similar in sun

and shade plants, but were low and comparable to forest understory species. Diurnal

measurements showed that PPFDs in both habitats were consistently above photosynthetic

compensation irradiance, and frequently exceeded saturating values. In addition, sun-and shade-

adapted individuals possessed stomata that tracked short-term fluctuations in PPFD. Thus A.

altissima may be unique in that it couples high, shade-plant like photosynthetic efficiency with

high photosynthetic capacity in high-irradiance, while stomatal attributes that optimize water use

efficiency are maintained in the shade. These features may contribute to success of A. altissima

in establishing in disturbance-prone urban systems, and facilitate its spread into more PPFD-

limited and competitive natural ecosystems.

Alves, C., et al. (2001). "Composition of extractable organic matter of air particles from

rural and urban Portuguese areas." Atmospheric Environment 35(32): 5485-5496.

Atmospheric particulate matter (PM10) was collected simultaneously Lit three sites in the

West Coast of Portugal, during an intensive campaign in August 1996. The sites were located in

line with the breezes blowing from the sea. The collected aerosol was analysed in relation to

black and organic carbon content. The particulate organic matter was extracted with solvents and

characterised by gas chromatography and mass spectrometry (GC-MS). Most of the organic

mass identified consists of alkanes. polycyclic aromatic hydrocarbons (PAH), ketones,

aldehydes, alcohols and fatty acids with both biogenic and anthropogenic origin. Many

photochemical products from volatile organic compounds emitted by vegetation were also

detected. Biomarkers such as 6,10,14-trimethylpentadecanone, abieta-8,11,13-trien-7-one and

Patchouli alcohol were observed at higher concentrations in the rural sites. Samples from the

urban site present lower values of "carbon preference index" and higher concentrations of

petrogenic/pyrogenic species, such as PAH. The PM10 concentrations and the total organic

extract measured for the more interior site were generally lower, indicating that dispersion and

dry deposition into the forest canopy were more important during the transport of the air masses

than aerosol production by condensation and photochemical reactions. On the contrary, The ratio

between organic and black carbon was, in general, lower at sites near the coast, especially for

compounds that evaporate at lower temperatures. The organic aerosol composition also seems to

be strongly dependent on the meteorology. (C) 2001 Elsevier Science Ltd. All rights reserved.

Spronken-Smith, R. A., et al. (2000). "Advection and the surface energy balance across an

irrigated urban park." International Journal of Climatology 20(9): 1033-1047.

The surface energy balance in an irrigated urban park in suburban Sacramento, CA is

observed. Three sites extend from the edge of the park to its centre, along a transect which is

aligned with the prevailing wind. Direct measurements of the fluxes of net radiation, soil heat

flux and evaporation are made at each site and the convective sensible heat is found by residual.

Strong advective effects on evaporation are observed, especially in the afternoon and evening.

The driving forces for this are the differences in surface and air temperature, and humidity,

between the cool, wet park and its warmer, drier built-up surroundings. The control of the

surroundings on park evaporation is demonstrated by comparing values with those from

synchronous observations in the surrounding suburbs and at an irrigated sod farm just outside the

city. Greatest evaporative enhancement is observed at the upwind edge. Throughout the

afternoon evaporation considerably exceeds the net radiation. This is interpreted to be due to the

microscale leading-edge effect which appears to be restricted to a fetch of about 20 m. Further

into the park evaporation also exceeds the net radiation in the afternoon due to the oasis effect.

At all sites the sensible heat flux density in the afternoon is negative. Daily and daytime total

evaporation from the park is more than 300% that from the integrated suburban area, and more

than 130% that from the irrigated rural grass site. The unlimited water supply and the high

temperatures of the park allow it to behave like a wet leaf in that its surface temperature seems to

be 'thermostatically' controlled-it never rises more than a few degrees above that of the park air

and for much of the day is cooler than the park air.

Shashua-Bar, L. and M. E. Hoffman (2000). "Vegetation as a climatic component in the

design of an urban street - An empirical model for predicting the cooling effect of urban

green areas with trees." Energy Build 31.

The cooling effect of small urban green wooded sites of various geometric configurations

in summer is the object of this study. It was studied experimentally at 11 different wooded sites

in the Tel-Aviv urban complex during the period July–August 1996. An empirical model is

developed in this study for predicting the cooling effect inside the wooded sites. The model is

based on the statistical analysis carried out on 714 experimental observations gathered each hour

from the 11 sites on calm days, when urban climate is expressed. Two factors were found to

explain over 70% of the air temperature variance inside the studied green site, namely, the partial

shaded area under the tree canopy and the air temperature of the non-wooded surroundings

adjoining the site. The specific cooling effect of the site due to its geometry and tree

characteristics, besides the shading, was found to be relatively small, about 0.5 K, out of an

average cooling of about 3 K at noon. The cooling effect of the green wooded areas on their

immediate surroundings at noon was also analyzed. The findings corroborate earlier studies that

the range is noticeable. At small green sites, the cooling effect estimated in this study is

perceivable up to about 100 m in the streets branching out from the site. The empirical findings

in this study permit development of tools for incorporating the climatic effects of green areas in

the urban design. Some policy measures are proposed accordingly, for alleviating the ‘‘heat

island’’ effect in the urban environment.

Shafer, C. S., et al. (2000). "A tale of three greenway trails: user perceptions related to

quality of life." Landscape and Urban Planning 49(3-4): 163-178.

Urban sprawl and renewed concern for the environment have helped create new policies

and initiatives designed to enhance community quality of life. Among these are transportation

enhancements mandated in ISTEA and TEA21. Funding through transportation enhancements

has helped to spur the designation and development of greenway trails with the intent of

fostering alternative transportation and generally making cities more livable. This paper presents

research conducted on three greenway trails in Texas. The research was based on the human

ecosystem concept and was intended to determine if and how such greenway facilities were

contributing to quality of life and how people might perceive such contributions based on the

way they used the trail (e.g. for transportation or recreation). Results indicated that most people

used greenway h-ails for recreation but that trails differed in user types and activities based on

location and policy. Users felt that these urban greenway trails were contributing most to

community quality of life through resident health/fitness, the natural areas they provide, better

land use and resident pride. They felt that they contributed least to diversifying industry, business

development and access to shopping areas or public transportation. Those who used trails for

transportation scored trails as contributing more toward reducing pollution, reducing

transportation costs and providing better access to work than did those who used trails only for

recreation. Implications for understanding use and users in the designation; design and

development of urban greenway trails are discussed.

Savard, J. P. L., et al. (2000). "Biodiversity concepts and urban ecosystems." Landscape

and Urban Planning 48(3-4): 131-142.

The association of biodiversity and urban ecosystems has usually concerned the impact of

urbanization on biodiversity. However, biodiversity concepts can easily be applied to the urban

ecosystem itself. As more and more people live in cities, restoration, preservation and

enhancement of biodiversity in urban areas become important. Concepts related to biodiversity

management such as scale, hierarchy, species identity, species values, fragmentation, global

approaches can be used to manage urban biodiversity. Application of these concepts in such

artificial ecosystems may yield important insights for the management of natural ecosystems.

Birds are highly visible and quite sensitive to changes in habitat structure and composition. Bird

species richness in urban ecosystems is influenced both by local and landscape characteristics

and a multiscale approach is essential to its proper management. People-wildlife conflicts are an

integral component of wildlife management in urban ecosystems and must be addressed.

Enhancement of biodiversity in urban ecosystems can have a positive impact on the quality of

life and education of urban dwellers and thus facilitate the preservation of biodiversity in natural

ecosystems.

Pauleit, S. and F. Duhme (2000). "Assessing the environmental performance of land cover

types for urban planning." Landscape and Urban Planning 52(1): 1-20.

Urban planning and decision-making for sustainable development urgently need data of

high spatial resolution to establish the relationship between the socio-economic performance of

the urban system and its different sub-units (i.e. housing schemes, commercial and industrial

developments, services) on the one hand and their environmental impacts of these subunits on

the other. To achieve this task, a system was developed to delineate urban land cover units. The

approach was tested for the city of Munich. The units delineate the fine-grained pattern of urban

built-up and open spaces. The typology was based on established categories of zoning and

development plans. In addition, the units were delineated on an aggregated scale to generate a

synoptic understanding of the urban "metabolism" for different "strategic" levels of urban

planning. A case study on urban hydrology is presented to characterize aspects of the metabolism

of the urban system. Additional case studies covered urban climates, energy demand for space

heating and carbon dioxide emissions. Results showed that the cover units and types had distinct

environmental features. Furthermore the causal links with urban physical and land use features

were investigated. Based on the hydrological case study, environmental targets and standards to

promote sustainable development are proposed.

Newell, R. G. and R. N. Stavins (2000). "Climate change and forest sinks: Factors affecting

the costs of carbon sequestration." Journal of Environmental Economics and Management

40(3): 211-235.

The possibility of encouraging the growth of forests as a means of sequestering carbon

dioxide has received considerable attention, partly because of evidence that this can be a

relatively inexpensive means of combating climate change. But how sensitive are such estimates

to specific conditions? We examine the sensitivity of carbon sequestration costs to changes in

critical factors, including the nature of management and deforestation regimes, silvicultural

species, relative prices, and discount rates.

Montague, T., et al. (2000). "Surface energy balance affects gas exchange and growth of

two irrigated landscape tree species in an arid climate." J Am Society Horticultural Sci

125.

Research was conducted to investigate how energy balance of bark mulch and turf

surfaces influence gas exchange and growth of recently transplanted trees. On several occasions

over a 3-year period, stomatal conductance and leaf temperature were measured throughout the

day on ‘Emerald Queen’ Norway maple (Acer platanoides L.) and ‘Greenspire’ littleleaf linden

(Tilia cordata Mill.) trees growing over each surface. Tree water loss was estimated using a

general transport flux equation applied to the tree crown apportioned between sunlit and shade

layers. Microclimate variables were measured over each surface with a permanent weather

station. Tree growth data were collected at the end of each growing season. Soil heat flux data

revealed that a greater portion of incoming radiation was prevented from entering the soil below

mulch than below turf. Due to this insulating effect, and consequent lack of evaporative cooling,

mulch surface temperature was greater, and emitted more longwave radiation, than turf. Leaves

over mulch intercepted more longwave radiation, had greater leaf temperature, and greater leaf-

to-air vapor pressure difference than leaves over turf. As a result, leaves over mulch had greater

stomatal closure than leaves over turf. Estimated tree water loss varied between surface

treatments and with climatic conditions. Trees over turf had greater shoot elongation and leaf

area than trees over mulch. These data suggest that gas exchange and growth of recently

transplanted trees in an arid climate may be reduced if planted over nonvegetative, urban

surfaces.

Konijnendijk, C. C. (2000). "Adapting forestry to urban demands - role of communication

in urban forestry in Europe." Landscape and Urban Planning 52(2-3): 89-100.

Similar to other parts of the world, European society is becoming increasingly urban,

both in a physical as in an economic and socio-cultural sense. As a result. the relationships

between society and nature, including forests. are changing, and forestry as structural

intervention in forest ecosystems has had to adapt itself to changing societal pressures and

demands. The planning and managing of woodlands in and near urban areas has been the most

directly affected by the urbanisation process. Many European countries have a long tradition of

'town forestry', serving as basis for current developments in urban forestry, i.e. the planning and

management of all forest and tree resources in and near urban areas for the benefit of local

society. Through the adaptation to the specific demands of local urban societies, a type of

forestry has emerged which is structurally different from classic forestry. It focuses, for example,

on the social and environmental values of urban woodlands rather than on wood production and

emphasising the importance of communication - ranging from information to participation/power

sharing between stakeholders. This paper investigates ways to communicate urban forests and

forestry to urban inhabitants and other stakeholders, based on results of a comparative study of

main European cities. It explores the role which urban forestry has been playing in the

development of forestry at large, especially with regards to better incorporating changing social

values and interests.

Kocher, S. D. and E. H. Williams (2000). "The diversity and abundance of North American

butterflies vary with habitat disturbance and geography." Journal of Biogeography 27(4):

785-794.

Aim We used data from the annual Fourth of July Butterfly Count for the years 1989-97

to examine patterns of species richness and total butterfly abundance across North America and

within topographically diverse and disturbed landscapes. Location We analysed counts from 514

different locations in North America. The counts represent all areas of the USA and southern

Canada, with a few Mexican sites as well, although most counts were in the eastern USA.

Methods First, we standardized published count data according to the effort expended per count

(total party-hours). Using regression analysis and analysis of variance, we then examined the

impact of latitude, longitude, topographical relief, habitat disturbance and different climatic

measures on the species richness and total abundance of butterflies per count. We also examined

the abundance of exotic species in disturbed landscapes. Results Our analyses suggest that: (1)

species richness is highest at low latitudes and near Rocky Mountain longitudes; (2) the total

abundance of individuals is highest in northern US latitudes and Great Plains longitudes; (3)

species richness but not total abundance increases with greater topographical relief; (4) species

richness and diversity indices are lower in more disturbed habitats; and (5) the abundance of the

introduced Pieris rapae (L.) is greater in more disturbed habitats. Main conclusions Different

factors control the abundance and species richness of North American butterflies. Along with

geographical location, habitat disturbance and topographical variability affect species richness.

Our analysis also shows the value of broad-based monitoring regimes, such as the North

American Fourth of July Butterfly Count.

Ehrenfeld, J. G. (2000). "Evaluating wetlands within an urban context." Ecological

Engineering 15(3-4): 253-265.

Coastal regions are among the most rapidly urbanizing places on earth. The numerous

effects of urbanization on hydrology, geomorphology, and ecology make wetlands in urban

regions function differently from wetlands in non-urban lands. Furthermore, wetlands ill urban

regions may take on human-related values that they lack in non-urban areas, as they provide

some contact with nature, and some opportunities for recreations that an otherwise rare in the

urban landscape. Evaluations of the success of restorations in urban regions require criteria first

to determine the kinds, and intensities of urban influence on the site, and secondly to assess

functional performance. The development of success criteria, at both the levels of assessment,

depends on the proper definition of a reference domain (the set of wetlands to which success

criteria will apply), and the documentation of a set of reference sites within the domain; both

must be based within the urban context appropriate for the region of interest. An example is

presented from a study of urban wetlands in New Jersey of a procedure for establishing the

reference domain, the reference set of wetlands, and criteria for the assessment of urban

influence.

Carlson, T. N. and S. T. Arthur (2000). "The impact of land use - land cover changes due to

urbanization on surface microclimate and hydrology: a satellite perspective." Global and

Planetary Change 25(1-2): 49-65.

Vegetation cover, surface moisture availability (wetness) and radiant surface temperature

constitute microclimatic variables derivable from multi-spectral satellite imagery. In addition,

fraction impervious surface cover and urban-induced surface runoff (RO) are obtainable from

such imagery when it is combined with a conventional image classification. Using AVHRR and

Landsat TM data, we illustrate how these parameters respond to urbanization with a case study

of Chester County, PA - a region that has undergone rapid urban development over the past

decade. Specific factors affecting the change in the surface microclimatic variables are discussed.

Based on a statistical analysis of the Chester County data, future values of these microclimatic

parameters can be predicted, given the characteristics of the initial land surface and an estimate

of the change in vegetation and urban coverage.

Beckett, K. P., et al. (2000). "Particulate pollution capture by urban trees: effect of species

and windspeed." Global Change Biology 6(8): 995-1003.

Particulate pollution is a serious health problem throughout the world, exacerbating a

wide range of respiratory and vascular illnesses in urban areas. The use of trees to reduce the

effects of these pollutants has been addressed in the literature, but has rarely been quantified. The

aim of the present study was to quantify the effectiveness of five tree species-pine (Pinus nigra

var. maritima), cypress (x Cupressocyparis leylandii), maple (Acer campestre), whitebeam

(Sorbus intermedia), poplar (Populus deltoides x trichocarpa 'Beaupre')-in capturing pollutant

particles. This was achieved by exposing them to NaCl droplets of approximately 1 mum

diameter at a range of windspeeds in two windtunnels. The deposition velocity (V-g) and particle

trapping efficiency (C-p) were calculated from these exposures. In addition, a variable dependent

on foliage structure [Stokes number (St)] was correlated with C-p to gauge the effect of tree

morphology on particle capture. Maximum C-p values ranged from 2.8% for P. nigra, to 0.12%

and 0.06% for P. trichocarpa x deltoides and A. campertre, respectively. The finer, more

complex structure of the foliage of the two conifers (P. nigra and C. leylandii) explained their

much greater effectiveness at capturing particles. The data presented here will be used to model

the effectiveness of tree planting schemes in improving urban air quality by capturing pollutant

particles.

Barradas, V. L. (2000). "Energy balance and transpiration in an urban tree hedgerow in

Mexico City." Urban Ecosystems 4(1): 55-67.

A series of sap flow (transpiration, TRP) and energy balance components measurements

were carried out in a representative tree hedgerow of Fraxinus uhdei in Mexico City (19° 19' N,

99° 11' W, 2250 m ASL). Measurements of sap flow in the trunks of the trees was selected as an

alternative tool instead of eddy covariance or Bowen ratio-energy balance methods in order to

determine the energy balance components of the tree canopy. These measurements were made in

October (end of the rainy season) and December (dry season) in 1997, from 8:00 to 17:00 LST.

TRP showed a unimodal pattern during the day. Mean daily transpiration was higher at the end

of the rainy season (1506 g m-2 d-1) than in the begining of the dry season (972 g m-2 d-1) with

maxima rates of 0.075 and 0.046 g m-2 s-1, respectively. During the rainy season net radiation

(QN) was mainly dissipated by latent (QE) and sensible (QH) heat, 60 and 34 %, respectively.

Latent heat increased in the day up to 184 W m-2. QN was dissipated by QH and QE by 75 and

25%, respectively, and QH had a maximum hourly value of 298 W m-2 during the day (8:00-

17:00 LST) in the dry season. Seasonal differences in QE and QH were probably due to

differences of water availability. Heat storage of the tree hedgerow canopy was found to be a

negligible component of the energy balance in both seasons. Actual transpiration of the system

was always lower than transpiration at equilibrium. This was probably due to a low water

availability in the substratum, a high atmospheric evaporative demand and an effective stomatal

control. Because the tree hedgerow was completely surrounded by paved areas and wind was

coming from a drier side, it is possible that transpiration rates were affected by advection

probably supressing TRP.

Spronken-Smith, R. A. and T. R. Oke (1999). "Scale modelling of nocturnal cooling in

urban parks." Boundary-Layer Meteorology 93(2): 287-312.

Scale modelling is used to determine the relative contribution of heat transfer processes

to the nocturnal cooling of urban parks and the characteristic temporal and spatial variation of

surface temperature. Validation is achieved using a hardware model-to-numerical model-to-field

observation chain of comparisons. For the calm case, modelling shows that urban-park

differences of sky view factor (psi(s)) and thermal admittance (mu) are the relevant properties

governing the park cool island (PCI) effect. Reduction in sky view factor by buildings and trees

decreases the drain of longwave radiation from the surface to the sky. Thus park areas near the

perimeter where there may be a line of buildings or trees, or even sites within a park containing

tree clumps or individual trees, generally cool less than open areas. The edge effect applies

within distances of about 2.2 to 3.5 times the height of the border obstruction, i.e., to have any

part of the park cooling at the maximum rate a square park must be at least twice these

dimensions in width. Although the central areas of parks larger than this will experience greater

cooling they will accumulate a larger volume of cold air that may make it possible for them to

initiate a thermal circulation and extend the influence of the park into the surrounding city. Given

real world values of psi(s) and mu it seems likely that radiation and conduction play almost equal

roles in nocturnal PCI development. Evaporation is not a significant cooling mechanism in the

nocturnal calm case but by day it is probably critical in establishing a PCI by sunset. It is likely

that conditions that favour PCI by day (tree shade, soil wetness) retard PCI growth at night. The

present work, which only deals with PCI growth, cannot predict which type of park will be

coolest at night. Complete specification of nocturnal PCI magnitude requires knowledge of the

PCI at sunset, and this depends on daytime energetics.

Panno, S. V., et al. (1999). "Impact of urban development on the chemical composition of

ground water in a fen-wetland complex." Wetlands 19(1): 236-245.

A 15-month-long hydrogeologic investigation of a fen-wetland complex in northeastern

Illinois, USA indicated the encroachment of ground-water-borne anthropogenic contaminants

into two of three high quality fens. Ground-water flow directions and chemical evidence

indicated that plumes of ground water with anomalously large concentrations of Na+ and Cl-

originated from a private septic system and from rock salt spread on an adjacent road. The

contamination, in turn, had an adverse effect on fen vegetation; within the plumes, diverse

vegetation was replaced by the more salt-tolerant narrow-leaf cattail (Typha angustifolia).

Ground water of the third fen contained large concentrations of SO42- as high as 516 mg/L. The

SO42- anomaly was observed on a transient and/or seasonal basis in the fen ground water and in

an adjacent marsh and pond. Isotopically light delta(34)S values in these waters indicated that

the addition of SO42- resulted from the oxidation of pyrite within underlying pear and/or pyritic

gravel. However, the large SO42- concentrations had no discernible effect on fen vegetation. The

results of this investigation indicate how easily construction of houses with private septic

systems and deicing agents from roadway maintenance can contaminate fen ground water with

relatively large concentrations of Na+ and Cl-, resulting in a significant loss of biodiversity in

fens.

Niemela, J. (1999). "Ecology and urban planning." Biodiversity and Conservation 8(1):

119-131.

Urban areas harbour diverse nature ranging from semi-natural habitats to wastelands,

parks and other highly human-influenced biotopes with their associated species assemblages.

Maintenance of this urban biodiversity for the residents and for its intrinsic value in the face of

increasing population and expanding cities requires that ecological knowledge should be better

integrated into urban planning. To achieve this goal understanding of ecological patterns and

processes in urban ecosystems is needed. The first step in the necessary urban ecological

research is to find out what kind of nature exists in cities. Second, knowledge about ecological

processes important in urban nature is required. Although ecological processes in cities are the

same as in rural areas, some of them, such as invasion by alien species, are more prevalent in

urban than in rural conditions. Third, based on ecological knowledge, management schemes

maintaining the diversity of urban nature should be designed. These procedures should also

include protection of urban nature, e.g. in urban national parks. Finally, as ecology alone cannot

provide the complex information about human influence on urban ecosystems, interdisciplinary

research involving natural and social sciences is imperative for a holistic approach to integrating

ecology into the process of urban planning.

Long, A. J. and P. K. R. Nair (1999). "Trees outside forests: agro-, community, and urban

forestry." New Forests 17(1-3): 145-174.

Planted forests are often considered to consist of tree plantings at a scale large enough to

satisfy such objectives as commercial production of timber and fiber, protection of watersheds,

and preservation of natural habitats. However, trees are planted also at greatly reduced scales in

agroforestry systems or as community woodlots to provide a mixture of products and services to

resident households, local communities, and regional cultures. Agroforestry systems represent a

major form of small-scale tree planting, where trees are grown in purposeful combinations with

agricultural crops and/or livestock in order to take advantage of tree-crop interactions, and

thereby enhance crop production, diversify farm output, stabilize or improve soils, or ameliorate

harsh environmental conditions. Some important examples of these systems in tropical countries

include home gardens, alley cropping, improved fallows, intercropped trees for shade and fodder

production, and trees planted in hedgerows and along fence lines. Throughout the tropics, there

is a large variety of indigenous practices and species mixtures that represent adaptations of these

systems to meet localized needs and opportunities. Research and development programs have

supported the expansion and refinement of many of these systems during the last 20 years, but

substantial constraints on tree planting still exist in the form of land-tenure practices, population

pressures that relegate agroforestry practices to degraded lands, subsistence needs that prevent

extended periods of tree growth, and insufficient technical information or technology

dissemination. Agroforestry systems in temperate, industrialized countries include combinations

of trees, pasture, and livestock; fruit or nut trees interplanted with vegetable or grain crops;

windbreaks and shelterbelts; multispecies riparian buffer strips; and forest farming systems for

specialty crops. Compared to the tropics, however, temperate-zone systems tend to focus on one

or two high-value crops, often involve some level of mechanization, and frequently represent an

opportunistic approach to improving the economic profitability of farms rather than meeting

subsistence needs. In both tropical and temperate regions, agroforestry systems and community

woodlots will be an important component of new sustainable agriculture and environmental

protection programs. Although species diversity is an essential feature of all agroforestry

systems, community forests generally involve planting only a few species in small woodlots near

farms, around villages, along roads, and as riparian buffers. Provincial or state governments and

the local populace are often involved in landownership and plantation establishment. Major

objectives of these forests are production of fuelwood for local consumption and of other tree

products for market; soil stabilization, reclamation, or improvement; and protection of water

quality. As with many other planted forests, the number of species widely used in community

forests has been relatively small, with the genera Eucalyptus, Pinus, and Acacia providing the

bulk of the species. Major issues with these "planted forests'' focus on rights for use of the

products, tending responsibilities once trees are established, protection until trees are large

enough for their designated use, increasing interest in using "native'' species, and greater

community involvement in planning and management. Trees planted along streets and

waterways, or as woodlots in parks and other public places, represent a major group of planted

forests in many urban and periurban landscapes. In addition to providing many of the same

environmental services that agroforests and community forests do, these urban plantings have

unique aesthetic and recreational value. For much of the world's ever-increasing urban

population, these may be the only tangible reference points for understanding planted forests.

These relatively little-recognized forms of planted forests - planted trees, to be more

appropriate - are now receiving much greater atte tion. There are, however, some serious

technical and sociopolitico-institutional constraints to their development as more widely adopted

systems in both tropical and temperate regions.

Kuttler, W. and A. Strassburger (1999). "Air quality measurements in urban green areas -

a case study." Atmospheric Environment 33(24-25): 4101-4108.

The influence of traffic-induced pollutants (e.g. CO, NO, NO2 and O-3) on the air quality

of urban areas was investigated in the city of Essen, North Rhine-Westphalia (NRW), Germany.

Twelve air hygiene profile measuring trips were made to analyse the trace gas distribution in the

urban area with high spatial resolution and to compare the air hygiene situation of urban green

areas with the overall situation of urban pollution. Seventeen measurements were made to

determine the diurnal concentration courses within urban parks (summer conditions: 13

measurements, 530 30 min mean values, winter conditions: 4 measurements, 128 30 min mean

values). The measurements were carried out during mainly calm wind and cloudless conditions

between February 1995 and March 1996. It was possible to establish highly differentiated spatial

concentration patterns within the urban area, These patterns were correlated with five general

types of land use (motorway, main road, secondary road, residential area, green area) which were

influenced to varying degrees by traffic emissions. Urban parks downwind from the main

emission sources show the following typical temporal concentration courses: In summer rush-

hour-dependent CO, NO and NO2 maxima only occurred in the morning. A high NO2/NO ratio

was established during weather conditions with high global radiation intensities (K > 800 W m(-

2)), which may result in a high O-3 formation potential. Some of the values measured found in

one of the parks investigated (Gruga Park, Essen, area: 0.7 km(2)), which were as high as 275

mu g m(-3) O-3 (30-min mean value) were significantly higher than the German air quality

standard of 120 mu g m(-3) (30-min mean value, VDI Guideline 2310, 1996) which currently

applies in Germany and about 20% above the maximum values measured on the same day by the

network of the North Rhine-Westphalian State Environment Agency. In winter high CO and NO

concentrations occur in the morning and during the afternoon rush-hour. The highest

concentrations (CO = 4.3 mg m(-3), NO = 368 mu g m(-3), 30-min mean values) coincide with

the increase in the evening inversion. The maximum measured values for CO, NO and NO2 do