Chapter 2. Diagnosis and goal setting

Chapter 2. Diagnosis and goal setting

Diagnosis and goal setting results in a conceptual ecological model, which is a graphical representation of the stressors and their ecological effects

Ex. Figure 2.1-Veldt grass, an introduced South African grass, is a stressor that causes a decline in Australian species

Figure 2.1 Conceptual ecological model for 34 ha of degraded woodland, Kwinana, Western Australia

Drivers of ecological change

1. Habitat conversion2. Pollution3. Overexploitation4. Introduced species5. Climate change6. Natural drivers like drought or disturbances caused by

fires, floods, hurricanes, or volcanoesEx. Habitat conversion and subsequent pollution were the

drivers that caused multiple stressors which caused ecological effects and affected ecological attributes

Figure 2.2- Biscayne Bay, Florida

Figure 2.2 A conceptual ecological model of Biscayne Bay (Florida, U.S.) used to assess the potential environmental impacts of resource use

Drivers of Ecological Change- 1. Habitat Conversion-Terrestrial

Figure 2.3 Approximately one-fourth of the Earth’s ice-free terrestrial surface is now cultivated

Drivers of Ecological Change- 1. Habitat Conversion-Aquatic

-aquaculture of fish and shrimp have caused 1/3 of the coastal mangrove forests to be lost in the past 50 years

-40% of the worlds population lives 50 km from coast and industry, urbanization, resort development seawalls, bridges, and jetties alter water and sediment movements

Mangrove pneumatophores at Boca Chica on the Texas Coast. It is the only place in Texas with amangrove forest or mangal.

Drivers of Ecological Change- 2. Pollution-Industrial sources

-result from energy production, manufacturing, mining, transportation, and waste incineration

-metals as well as spent nuclear fuel from energy production are toxic

-chemicals like polycyclic aromatic hydrocarbons (PAH) (from leaking oil and runoff; carcinogens), 150,000 synthetic chemicals with 1000s more manufactured each year in pesticides, solvents, acids, dioxin (chlorinated hydrocarbon that is toxic to humans formed during incineration and paper bleaching), phthlates (chemical used soften plastic toys that may be toxic and banned in 2008).

Drivers of Ecological Change- 2. Pollution-Agricultural and human habitation sources

-pathogens from livestock that in some cases can infect humans (anthrax, worms)

-salts from feeds and fertilizers can affect soils-pharmaceuticals like hormones and antibiotics cause

health problems with reproductive systems and bacterial resistance

-organic matter, fertilizers as well as nitrogen and phosphorous compounds cause eutrophication

-ash, particulates, and carbon dioxide contribute to respiratory problems and climate change Table 2.2

Table 2.2

Drivers of Ecological Change- 3. Overexploitation

Figure 2.4 The Great Barrier Reef Marine Park designated no-fishing zones to allow populations of fish to recover like this Australian coral trout

Drivers of Ecological Change- 4. Species Introductions

Figure 2.5 Burmese pythons, such as the one held here by a park ranger, are popular pets in the United States and have created major ecological problems in Everglades National Park

Drivers of Ecological Change- 5. Climate change

Drivers of Ecological Change- 6. Natural drivers

-natural disturbances like hurricanes, floods, fire, or volcanic eruptions are major drivers of ecological change

-typical pattern of disturbance for an ecosystem is termed the disturbance regime Ex. Prairie pothole wetlands require drought once a decade so plant species that cannot germinate underwater can become established

-humans have changed the natural disturbance regimes of many ecosystems Ex. flood control structures on rivers and fire control policies

-ecosystem changes that are novel, too frequent, or too extensive cause unstablity

Figure 2.6 (A) The hydrology of Tram Chim National Park is managed to mimic historic flood pulses. (B) Flooded wetlands, provide habitat for many waterbirds and pulses maintain vegetation

Figure 2.7 Ecosystem disturbances (represented by blue dots) vary in frequency (vertical axis) and area (horizontal axis). Forest fires and tree gaps are less frequent relative to recovery time or disturb smaller portions than human-caused disturbances like smelter damage.

Ecological effects caused by the 6 drivers (habitat, pollution, overexploitation. introduction, climate, and natural drivers) - 1. Population declines 2. Habitat fragmentation; 3. Spread of introduced species 4. Changes in species interactions; 5. Changes in disturbance; 6. Changes in trophic structure

Population declinesInfluenced by three factors:1. Environmental stochasticity –caused by six drivers2. Demographic stochasticity –erratic changes in birth and

death rates of individuals3. Genetic events- As populations decline there may be fewer alleles, less

heterozygosity (Figure 2.8), and more maladaptive alleles. Natural selection can limit the incidence of these and promote adaptive alleles but small populations are more susceptible to inbreeding and genetic drift events like the founder effect

-the synergistic impact of negative effects of 1-3 can lead to an extinction vortex

Figure 2.8 (A) An allele is one form of a gene. (B) Each progeny inherits two alleles for every gene, one from each parent

Figure 2.9 The Tasmanian devil is a carnivorous marsupial endemic to the island of Tasmania and is in danger of extinction due to low genetic diversity and inability to combat a fatal disease


Habitat fragmentation (HF)

Figure 2.10 Deforestation in southern Bahia, Brazil has decreased biodiversity and adversely affected river water quality

Figure 2.11 Four different types of spatially structured populations. A nonequilibrium metapopulation (mp) loses its ability for migration as patches are lost and mp cease to persist


Introduced species that are invasive or form hybrids

Figure 2.12 Hybridization between the native California tiger salamander and an introduced tiger salamander yields hybrid progeny with a survival rate higher than that of either parent species


Changes in species interactions

Figure 2.13 A dune slack wetland is flanked by active dunes, some of which are being stabilized by woody vegetation. This woody vegetation is periodically removed to restore rare species that carry on species interactions within wetlands formed by shifting sands


Changes involving disturbance and succession


Changes in trophic structure

Figure 2.14 Changes in trophic structure with increasing nutrient loading in shallow temperate lakes in Europe

Figure 2.15 The Minneapolis Chain of Lakes is surrounded by the city of Minneapolis and has become degraded by phosporous in stormwater runoff, which dramatically changed the trophic system

Ecoregions and Landscape analysis

Ecoregions-geographic units corresponding to natural features


Landscape-within an ecoregion, ecosystems and human uses form repeated patterns

-landscape analysis begins by delineating boundaries of the assessment area Ex. Problems related to nutrient transport, soil erosion, and flooding may involve landscape analysis of a drainage basin Fig. 2.16

-may center on a site of interest based on rare or endangered species like rhinos and tigers in Chitwan National Park in Nepal, where landscape analysis was used to create buffer zones and restore forests in these areas Fig. 2.17

Figure 2.16 A drainage basin is the land that can contribute surface runoff or outflow to a waterbod like Hunters Creek in Rocky Mountain National Park in Colorado

Figure 2.17 The government of Nepal encouraged reforestation and sustainable forest management within buffer zones around Chitwan National Park to improve tiger and rhino habitat


Landscape pattern (structure) refers to the configuration of different patches within the landscape and is usually represented using maps created with geographic information systems (GIS)

-GIS depicts patches of natural ecosystems or human-modified areas as well as linear features called corridors like rivers and roads Fig. 2.18

-landscapes may be categorized by degree of habitat destruction, connectivity, and level of modification into four levels of habitat destruction Fig. 2.19

Figure 2.18 Within a landscape, patches (P) are tracts with different land covers; corridors (C) are linear features such as rivers, roads, and fence lines

Figure 2.19 Landscapes can be classified by degree of habitat destruction and the connectivity and level of modification of the remaining habitat

Site Analysis

Baseline survey-current state of an ecosystem using data from field surveys

Reference sites-intact ecosystems used as comparisons to restored or managed sites Fig. 2.20

-plants are often described by mapping vegetation communities and by compiling plant lists

-animals are surveyed in a similar fashion when sessile but mobile animals are surveyed to determine whether species are residents, use the site for breeding, rearing young, migration, or seasonally

-some species become rare because of human actions and others have always been rare Table 2.3

-population viability analysis is used to determine if rare populations might persist using demographic data Ex. Tasmanian devil, p. 543

Figure 2.20 Reference and managed forests in the Upper Peninsula of Michigan

Table 2.3

Assessment of Ecological Resilience

Ecological resilience-capacity of an ecosystem to withstand change or to recover after disturbance

-conferred by adaptations possessed by the species within an ecosystem that allow them to rebound after major changes

-extent of landscape alteration affects resilience Fig. 2.21

Figure 2.21 As the degradation of a restoration site and surrounding landscape increases, likelihood of rapid and full ecological restoration declines (indicated by size of circles)


Resilience and response to stress can be characterized as one of three models:

Figure 2.22 Models of three potential recovery pathways


How do we know if an ecosystem fits a model that has a high chance of successful recovery?

-tools have been developed for particular regions and ecosystems by researchers that have worked in areas

Ex. Obura and Grimsditch (2009) developed a resilience assessment tool for coral reefs that uses 61 resilience indicators that cover aspects of nine factors: benthic cover, physical condition of the substrate and water, coral condition, coral population viability, coral associates, fish groups, connectivity to the seascape, as well as human impacts and management capacity Fig. 2.23

Figure 2.23 Measuring coral recruitment to assess the status of coral populations for a resilience assessment

SMART goals-Specific, measurable, achievable, reasonable, and time-bound

Specific-clearly capture a community or species to target for restoration

Ex. Restore marsh or grassland rather than just vegetation or improve habitat for a focal (flagship) species or group of species. In the restoration of Sweetwater Marsh in CA, the goal was to restore marsh vegetation to improve habitat for the light-footed clapper rail, a focal bird species

Measureable-Quantify levels of restoration and establish ways to evaluate progress toward goals. How does it compare to a reference ecosystem?

Achievable and Reasonable-Base goals on realistic assumptions.

Time-bound-Goals should specify the amount of time it will take to achieve them.

Goal setting for large-scale and high-risk restorations

Backcasting-a method for setting incremental goals to solve problems that will require long-term commitments and be strongly influenced by external forces with high potential to impede progress.

Chapter 2. Diagnosis and goal setting

Documents

ecological effects

drivers of ecological

ecological attributesfigure

ecological restoration

natural drivers

climate change table

habitat conversionaquatic

habitat conversion2