Bufferstrips for biomass production

1. Bufferstripsfor biomassproduction Ben Christen, University of Aarhus, Denmark

2. Contents • Background • Buffer function and designs • Establishment • Performance • Policy development

3. Background • Water Frameworkdirectiverequires ’goodeclogical status’ by 2015/2027 • Danish ’Plans for the aquaticenvironment III’ aim to furtherreducenitrate pollution by 30% • Bioenergy policy ’Grøn Vækst’ (green growth) openslakeshores and stream banks • 5000 miles of watercourses • Production potential >100,000 tonnes/a

4. Buffer design and function All Buffer Types • N-removal: 30-99% • P-removal: 20-99% • Pesticide removal: 10-100% mainly dependent on width Most suitable layout for biomass production identified: 3-zone structure with grass, short rotation forestry + undisturbed zone

5. Grass strip Function • Slows and spreads runoff • Filters sediment • Resists erosion by rill flow • Takes up nutrients during growing season • Denitrification Production potential • Biomass for bioenergy(6-16 t/DM/a) • Hay and silage • Pasture for extensive grazing • Biogas feedstock

6. Short rotation forestry zone Function • Infiltration of water passing through grass strip • Captures fine sediment • Removes pesticides • Immobilises nutrients • Denitrification Production potential • Woodchips (5-14 t/DM/a) • Firewood (5-8 m3/a) • Pulpwood • Timber for higher value uses

7. Undisturbed zone Function • Reduces bank erosion • Protects buffer structure in flood events • Buffers maintenance and harvest operations in other two zones • Enhancement of stream ecology (shade, debris) Production potential • Occasionally timber of larger dimensions but low quality

8. Buffer design variants Fast Bioenergy Miscanthus, reed canary grass, willow, alder, poplar Higher value timber Grass mixture, bird cherry, oak, field maple, hornbeam, lime

9. Buffer design variants continued Gentle slope Reed grass or grass mixture, alder, birch, field maple, poplar 10% slope Grass mixture, birch, field maple, pear, black locust, alder

10. Buffer design variants - drainage Drains broken by ditch before reaching buffer strip Reed grass, alder, poplar, downey birch, elm

11. Establishing a productive buffer

12. Landscape impactprojection

13. Planning Ditch Grass strip Grey and red alder

14. Construction – May 2011

15. Establishment

16. Performance forecast

17. Economics

18. Policy development:Fuzzy Cognitive Mapping (FCM) • Procedure to involve different stakeholders in a research or management process • Method to extract, depict and analyze different kinds of knowledge • Way to put academic, regulatory and practical knowledge on equal footing in an expert network

19. FCM-how-toExamplequestion: Why do touristscome to Scotland and howdoesthataffect rural development? Wildlife Concepts -pristinewilderness -wildlife -salmonfishing -grousemoor management -golf courses -forestry -rural employment -transport infrastructure -… Pristinewilderness Forestry Salmonfishing Rural employment Grousemoor management Transport infrastructure Golf courses

20. An expertnetworkfrom the CREW Workshop, 03.11.11

21. Policy impactsderived