Impacts of landscape treatments on plant species richness within road corridors and adjacent ecosystems - Rosalyn ThompsonPresentation Transcript
Impacts of Landscape Treatments on PlantSpecies Richness within Road Corridors and Adjacent Ecosystems Rosalyn Thompson University College Cork SIMBIOSYS FINAL CONFERENCE Dublin: 28th June 2012.
Road Verges: 3 Research Areas1. Species richness: (a) Road Verge vs. Adjacent Land. (b) Pre-guidelines vs. Post-guidelines2. Contribution of Soil Seed Bank3. Nutrient status of Soil in Road Schemes Preliminary Conclusions
Research in Context - Background• 2006 NRA Produced Guidelines• Landscaping of Verge area: Move away from a high input/ horticultural approach to one following an Ecological Landscape Design approach.• Opportunity in 2009 to study Pre- and Post- guidelines sites.
Research in Context - How slopes were landscapedTraditionally, this involved:• finishing engineering aspects• covering with topsoil image: Lego• treating with herbicide Glenealy Landscaping• applying fertilizer• planting…. Ecowitch A.C.E.S.
New Approach• Use subsoil (soil slopes) or NO soil (rock/scree)• Avoid herbicides and fertilizer• Create Open Habitat Mosaics (OHM) incorporating native species of local provenance: Soil Slopes. Allow Natural Recolonisation (NR): Rock/scree Slopes. Soil Slope (OHM) Rock/scree Slope (NR)
Species Richness: Road Verge vs. Adjacent Land Use Road VergesRock/Scree Slope Soil Slope Wider verge Adjacent FieldsMargin Centre-improved grassland Centre-tillage
1. Species Richness: All Road Sites 18 16 14Mean no. of Species 12 10 8 6 4 2 0 KM west from Wexford Road Verge Field Margin Field Centre
Species Richness on Road Verges:Soil Slopes – All Species – Comparison of Treatments Mean species richness in semi-naturalIncluding grasslandsall species Treatments are different (P< 0.05)
Species Richness on Road Verges: Soil Slopes (II) - Comparison of Treatments Mean speciesNative richness inspecies semi-naturalonly grasslands Post Treatments are different to Both Pre treatments (P< 0.05)
Species Richness Road Verges Rock/scree (native species)Early Summer only Early & Late Summer Treatments are not sig. different (P > 0.05)
2. Below-ground plant community: the contribution of the Soil Seed Bank2010: Soil collectedspring followingplant survey.Outdoor germination2 seasons
Species recorded Rock face Glebe Co. Kerry (NR): 2009: Quadrats (Q); 2010: Soil Seed Bank Trial (SSB) Species Q SSB Species Q SSB Species Q SSB Aegopodium Geranium Epilobium podagria. robertianum. parviflorum Angelica Lythrum Hypericum sylvestris salicaria humifusum Athyrium filix Rubus Juncus effusus lemina fruticosa Elytrigia Teucrium Plantago major repens scorodonia Hedera Poa pratensis Ulex europaeus Juncus Scirpus conglomeratus Cardamine setaceus flexuosa Lonicera Carex pendula Veronica periclymenum persica Rubus idaeus Epilobium Viola riviniana ciliatum Species Richness: Q = 8; Both = 5; SSB = 11; TOT = 24
3. Soil Fertility Subsoil TopsoilGrasslands with higher numbers of native plantspecies require LOW soil fertility.
Preliminary Conclusions• Higher mean species richness in Road Verge than either Margin or Centre of the adjacent field.• Seed bank data important – particularly to NR.• Topsoil nutrient status should be determined: (low nutrient status may costs/effort involved in its alternative disposal/incorporation)• If POST-GUIDELINES treatments are producing results ≥ PRE-G then POST is to be adopted as the more sustainable approach.
Acknowledgements• SIMBIOSYS project (2007-B-CD-1-S1) is part of the Science, Technology, Research & Innovation for the Environment (STRIVE) Programme 2007 – 2013, funded by the Irish Government under the National Development Plan 2007-2013 and administered by the Environmental Protection Agency
With thanks to….• Dr Pádraig Whelan (UCC), Professor Mark Emmerson (QUB) - Supervisors• Lisa Dolan (UCC) – Research Assistant• Dr Nova Sharkey (TCD) – Research Assistant• Máiread Kiely (UCC) Senior Technical Officer Plant Science• Paul Green (Botanical Society of the British Isles)• Steven Darby MSci (Chemistry)• Louise Russell, Jovanna Arndt, Dearbhail McKenna, Simon Mills – Field Assistants• Mary Hamilton, Aisling O’Shea, Eimear Egan – Greenhouse Assistants• Dr Sonia Monteiro, Aisling O’Shea – Lab Assistants• All our landowners• Kerry, Cork, Waterford and Wexford City and County Councils
Soil Nutrients & Mean Species Richness (Season A). Soil slopes: pre- and post-guidelines (i)25 [P] mg/kg20 Total Kjeldahl Nitrogen (g N/Kg dry wt) MEAN s.r1510 5 0 R11-pre R12-post R13-pre R21-post R14-pre R6-post R20-pre R27-post R16-pre R25-post R17-pre R28-post R19-pre R7-post Road Verge Sites (pre-guidelines = planted; post-guidelines = open habitat mosaic) east to west [P] min. fertility [N] min. fertility Dixie & Bisgrove (1996).
Soil Nutrients & Mean Species Richness (Season A). Soil slopes: pre- and post-guidelines (ii)25 [P] mg/kg [N] g/kg20 MEAN s.r1510 5 0 R12-post R0-pre R21-post R1-pre R6-post R23-pre R27-post R4-pre R25-post R9-pre R28-post R5-pre R7-post R8-pre Road Verge Sites (pre-guidelines = standard grass seed mix; post-guidelines = open habitat mosaic) east to west [P] min. fertility [N] min. fertility Dixie & Bisgrove (1996).
Pre-guideline planting…• Incorporated non-native species which are out of context or have an urbanizing effectFagus sylvatica Purpurea Cotoneaster horizontalisCopper Beech Wall or Rock Cotoneaster• …some of which are now invasive
Community Stability Sorenson β-Diversity Score for each siteUsing Sørensen Pair Treatment Score 7 PL 0.29similarity index 3 NR 0.33 8 NR 0.38 8 PL 0.39 2c 6 NR 0.4β= 6 PL 0.5 4 PL 0.5 S1 + S2 4 NR 0.55 5 PL 0.57 7 NR 0.57 3 PL 0.590 = dissimilar 5 NR 0.631 = identical 2 PL 0.63 2 NR 0.67 1 PL 0.7 1 NR 0.7
Data Collection: Above-ground plant community 2009:above-ground plant communities surveyedTwo 2m x 2m quadrats (adjacent to carabid pitfall traps)
Plant Communities & Invasion Resistance Above-ground plant communities:• 93 species of higher plants and ferns PL 34 35 21 NR• 87 “Native” 4 Non-native (2 undetermined) Below-ground plant communities• 17 additional species PL 4 2 11 NR 4 = Non-native
Study Design• Study area N25/N22 primary route• 310km east to west transect• 8 pairs of rock/scree sites• Each pair: 1 x pre- and 1 x post-guidelines• Similar in age, aspect and geographical location