Post on 20-Oct-2014
description
Peatlands and Greenhouse Gas Emissions
Mark Cooper, Chris Evans, Piotr Zielinski, Tim Jones, Annette Burden, Mike Peacock,
Chris Freeman, Mike Billett, Nick Ostle, Pete Levy, Kerry Dinsmore, et al.
Talk Structure• CEH Carbon Catchment Project• Effects of drainage ditch blocking• Effects of atmospheric deposition
Acknowledging CEH, WCCL and Bangor University
UK Soil C
Auchencorth Moss
Moor House
Forsinard
Upper Conwy
CEH ‘Carbon Catchments’
• Ecosystem carbon balance being measured at four peat catchments (land-atmosphere and dissolved C fluxes)
• Experimental components:– Drained/undrained (Forsinard)– Burnt/unburnt (Moor House)– High/low nitrogen deposition (Auchencorth)– High/low acid deposition (Conwy)
DOC input in precipitation
Evasion of CO2 and CH4 from stream surface
Downstream export of DOC, DIC, POC, CO2, CH4
Land surface exchange of CO2 and CH4
Floating chambers or tracer gas injections
Outlet measurement station: discharge and aquatic C concentrations
Array of static chambers Eddy covariance
measurement system (flux footprint)
Peat cores for measuring C accumulation rate
Gas exchange from bog-pool system
Carbon CatchmentsBaseline monitoring
Migneint
Moor House
Auchencorth
Forsinard
CARBONBALANCE
CO2 Exchange Methane
Dissolved
Gases
Dissolved
Carbon
Main Peatland Carbon Fluxes
Site Net CO2 exchange
CH4 DIC DOC POCNet C balance
Mer Bleue, Quebec1 -40 4 15 -22
Degerö Stormyr, N. Sweden2 -51 11 4 13 -23
Glencar, SW Ireland7,8 -55 5 15
Auchencorth, E. Scotland3,4 -115 <1 15* 25 4 -70
Moor House, N. England
-20 7 10 23 18 +38
Migneint, N. Wales
5 1 19 1
Carbon Catchment: Nant Y Brwyn
• Upland Blanket bog which forms part of the Migneint • Nant Y Brwyn is approx 1.68km2
• Mean annual rainfall is approximately 2200 mm yr–1
• Mean annual temperature is 5.6°C• Main vegetation consists of Calluna, Juncus,
Sphagnum, Eriophorum• Light grazing between May and October
Carbon Catchment: Nant Y Brwyn• Flux Tower• Automated Weather Station• Static Gas Chamber sampling• Automated River Monitoring• Complete carbon budget is still
a working progress
Methane
Landscape Scale
• Aerial Photography• Field Surveys• High Resolution LiDAR
Nant Y BrwynEstimated Habitat Coverage (%)
Riparian Juncus FlushUndrained Cal-luna HeathSphagnum GullyUpland Juncus FlushAcid Grassland
Riparian Juncus flush covers 12% & contributes 87% of the overall CH4 budget
Riparian Juncus Flush 86.97%
Undrained Calluna Heath 7.30%
Sphagnum Gully 3.91%
Upland Juncus Flush 1.08%
Acid Grassland 0.74%
Contribution to Landscape CH4 Budget
Llyn Serw, Migneint
• Conwy, North Wales• Habitat – wet Calluna heath on Blanket Peat
– NVC M19 – Calluna, Eriophorum sp., Sphagnum sp.
• Historical Drainage with ditches– 1920’s & 1930’s running S-SE (mostly re-vegetated)
– 1970’s & 1980’s running N-S• NT blocked ditches in pilot study in 2008
National Trust peat restoration pilot study, Llyn Serw
CH4CH4
CO2CO2
CH4CH4
CO2CO2
CO2CO2
Transect of trace Gas Measurements
A DCB E F A DCB E F
Dip wellGas Measurement
Transect Code
Gas Measurements - between 11am – 3pm
Before:
After:
Two years after:
Results Summary
• Infilled ditches contribute a significant percentage to landscape scale methane budget despite occupying a tiny percentage of the landscape
• Compensating increase in CO2 sequestration not yet quantified
• Vegetation in ditch is critically important for CH4 flux
• Is this a transient or a long-term effect?
Defra project to assess the impacts of peat restoration on the GHG balance
• Five year field experiment to evaluate the effects of peat restoration on methane emissions and the overall C and GHG balance (with Leeds and Open Universities, National Trust)
• Replicated study of 12 ditches, with 2 ditch-blocking treatments, pre- and post treatment measurements (CH4, CO2, DOC, discharge, etc)