Impacts of road landscape treatments on biodiversity within road corridors and adjacent ecosystems - Pádraig Whelan

Work Package 2:

Impacts of Road Landscape Treatments on Biodiversity within

Road Corridors and Adjacent Ecosystems

P. Whelan, ERI, BEES,

University College Cork

Roads in the landscape

• Breaks in continuity of landscape features?

• Opportunity for creation of habitats and continuity?

Road landscapes as ecosystems•Are the

species/communities on

roads different from

surrounding

communities?

•Do the

species/communities on

roads interact with

surrounding

communities.

•Provision of continuity

of habitats and

movement of fauna.

•Potential to enhance

biodiversity in a

landscape?

•Ecosystem services (predation, biocontrol,

carbon fixation, pollination, rainfall

attenuation, flood prevention, etc.).

Roads - Biodiversity at three levels• Landscape diversity

creation,

restoration,

compensation and/

or replacement in

largely agricultural

landscapes (not

reported here).

• Species level. Plant

and animal

diversity along

roads.

• Gene level.

WhitethornDara Stanley

•Biodiversity on roads

•Interactions between biodiversity on road and surrounding systems?

•Management of biotic and abiotic landscape treatments promote invasion resistance to aliens

•Impacts of road management on intra-specific genetic variation

•Guide to landscape treatments for national road schemes in Ireland (NRA, 2006)

Roads - Objectives

A Guide to Landscape Treatments for

National Road Schemes in Ireland

(NRA, 2006)• Pre-Guidelines

• Standard agricultural grass

seed mixes

• Use of plants available in

the horticultural market

• Highly fertile topsoil with

added fertilisers

• High maintenance -

chemically & physically

• A horticultural outcome

• Post-Guidelines

• Ecological landscape design

• Verge fits with wider landscape

• Native species of local

provenance

• Natural recolonisation

• Subsoil where possible

• Low maintenance

• Increased sustainability

Both pre and post treatments in place in 2009

New Approach to

Verge Treatments Standard Grass

Seed (Soil Slope) Planted

(Soil Slope)

Planted

(Rock/Scree)

SGSM

(Wider Verge)

Open Habitat Mosaic

(Soil Slope/Wider Verge)

Hay Strewing

(Soil Slope/Wider verge)

Natural

Recolonisation

(Rock/Scree)

Distribution of study sites

300km transectTralee to Rosslare

Wider Verge Area

Hedgerow/Fence-line

Adjacent Field

Road

Position of Quadrat and Pitfall Trap

Field Margin

Wider Verge Sand Bed

Field Margin Quadrat

adjacent Pitfall

Position of Sand Bed

Immediate Verge Area

Sampling of roaded landscapes

• Pitfall traps

• Plant quadrats

• Hedgerow surveys

• Sand beds

• Mammal traps

• Bird surveys

• Soil seed bank

• Pan traps – (L. Mountsey)

• Grid references

• Hedgerow aspect

• Margin widths

• Slope

• Weather

• Soil nutrients

• Photographic record

Biotic sampling and abiotic

measurements taken at road sites

Biotic Abiotic

Road Verge1= Pre-guidelines

Centre of adjacent field

Soil Slopes: Pre vs Post Guidelines and

Adjacent Field

Below ground plant community• Soil seed bank (more later from R. Thompson)

Further information

Carabid community structure & Road Landscaping

Carabid Community Structure &

Road Landscaping

Invasion Resistance

(ongoing).

Japanese Rose Rosa rugosaPics. Wikimedia Commons

Thanks to Tracy Smith Kerry Co. Co.

M7 – Castletown to Nenagh

Biodiversity resulting

from different treatments

(natural recolonisation,

hay strewing, standard

grass seed mix,

commercial wildflower

seed mix).

Major part completed in

Nov 2010

Atkins, Bowen-Somag (B.

Barron), J.Kelly (Laois

Co. Co.)

Long term, large scale, experiment

Biodiversity at the genetic level

• Effect of road landscaping on

gene flow in Crataegus

monogyna (Whitethorn).

• All populations (from Ireland

and mainland Europe)

indicate that all samples

belong to a single gene pool.

• High levels of inbreeding

which could be a result of

founder effect.

Implications for discussion on local

provenance - Jones and Evans (1994),

Jones et al. (2001) – differences in

phenology, thorniness and resistance to

mildew. Not resolved.

C. Spillane team NUIG

Implications – The future?• Early days!

• Preliminary findings

• Road communities are

different from those of

improved agric grassland.

• Of the groups processed,

pre vs post treatments vary

from group to group but

post shown to be as good

as, if not better than, pre for

biodiversity and is more

sustainable because of

lower inputs, so post is to

be preferred.

Acknowledgments

• Declan Little

• Kevin Collins

• Pat Peters

• Landowners

• Local Authorities

Thank you EPA

• Any Questions ?

St Patrick’s Cabbage, Rock Face, Macroom, Co. Cork.

Improved Grassland GA1

Reference Sites

Semi-natural Grassland

Carabid community structure & Road

Landscaping

• Multivariate analysis revealed significant differences in carabid community

structure according to treatment (F6,40 =1.9223, P=0.002)

• Pairwise tests revealed significant differences between in the carabid community structure of improved agricultural grassland (control) and all

other road treatments

• Carabid community structure of pre and post road treatments did not differ from each other

Invasion ResistanceProposed experimental design:

1. Treatment applied

NR

sods

(low fertility)

2. Method of IntroductionSeed

3. Replication

SGSM

sods

(high fertility)

Rhizomes/Roots Stems (semi-ripe

cuttings)

R1………………….. R10

(A.) Polygonum sp. & (B.) Rosa rugosa

Continued…..

Topsoil

(high fertility)Subsoil

(low fertility)

Invasion ResistanceProposed experimental design:

Subsoil

(low fertility)

Seeds Stems

R1………………….. R10

Total sampling

effort:

Polygonum sp. 120

Rosa rugosa 120

Buddleja 80

P. Fragrans 20

Grand Total 340

C. Buddleja

D. Petasites fragrans

Topsoil Subsoil

Rhizomes

R1…………………..R10

SGSM

sods

(high fertility)

NR

sods

(low fertility)

Topsoil

(high fertility)

N7 Experimental Design

Natural Recolonisation

Hay Strewing

Standard Grass seed mix

Commercial Wildflower seed mix

Topsoil

Flora diversity

Pollinators

Natural Enemies

Birds and Mammals

Flora diversity Natural Enemies

Clover Carbon Rhinanthus Do-nothing

Pollinators

Landscape

Scale

3m x 800m

Road Segment

Scale

3m x 20m