EP Intergroup on Sustainable Development: Cutting Carbon by Cutting peat The potential effects of wi

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EP Intergroup on Sustainable Development
Cutting Carbon by Cutting peatThe potential
effects of wind farm developments on peatland
vegetation, and the benefits of improved
management on the carbon store/sink A UK
perspective.Dr Sarah CroweEnvironmental
Research Institute, UHI Millennium Institute.
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Introduction Peatlands and Vegetation

• Peatlands are the largest terrestrial Carbon
  reserve in UK 3 billion tonnes
• Vegetation and peatland hydrology closely linked
  especially Sphagnum moss

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Landscape change in damaged peatlands

• UK peatlands undergone widespread degradation
  through pollution and land-use. Provides
  example of possible vegetation change in wind
  farms

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Vegetation gradients on damaged peatlands
Nether Reddale Clough, North-west England 9
months (Mar-Nov 2003) averaged water table data
and generalised vegetation pattern

• Gully edge vegetation greater water table
  fluctuations
• Move away from edge water table is more stable
  and vegetation changes

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• Potential long-term loss of species
• Creates problems if site undergoes restoration
• Creates problems as major peat-building species
  cant be re-established

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Misclassification of peatland sites

• In the Lewis EIA the proposed site was described
  as moving towards a Dry Heath trajectory.
• In addition the LANDSAT TM imagery classified
  most the peat bogs as eroded
• Use better airborne imagery however can often
  reveal a more complex story

• However the majority have been re-vegetating
  over the last 60 years

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Alternative peatland Carbon management

• Restoration of degraded peatlands a viable
  long-term solution for Carbon management

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Summary

• Degraded peatlands could represent analogues of
  damage caused by wind farm construction
• Exposed, dry erosion gully edges show
  considerable evidence of vegetation change
• Vegetation is stressed and susceptible to
  further damage leading to removal of plants
• The resulting bare peat creates two major
  problems
• Oxidation and potential CO2 release
• Lowered Carbon uptake through lack of
  photosynthesising vegetation
• Restoring degraded peatlands either by
• Re-vegetating bare peat
• Better management of degraded vegetation
• Help improve peatland Carbon sequestration and
  long-term carbon storage in a major terrestrial
  Carbon store
• Reduce associated particulate and dissolved
  Carbon loss