PARENT SESSION
Organized Oral Session 13: Gas exchange and global change in peatlands: From soil to satellite
Organizer(s): J Limpens, G Schaepman, MB Nilsson, and MM Heijmans
Tuesday, August 9, 8:00 AM - 11:30 AM, Meeting Room 510b, Level 5, Palais des congrès de Montréal
Scaling peatland carbon dioxide and methane exchange from chambers to the landscape.
Moore, Tim 1, Bubier, Jill2, 1 McGill University, Montreal, Quebec, Canada2 Mount Holyoke College, South Hadley, MA, USA
ABSTRACT- Carbon dioxide and methane gas exchanges in peatlands vary both spatially and temporally at different scales, making the extrapolation from point measurements to the landscape a challenging task. Using a range of Canadian peatlands as case studies, we examined the process of scaling plot-level gas flux measurements to the landscape using chambers, towers, and remote sensing. Methane flux has much larger variability than carbon dioxide flux. We used Landsat (30 m resolution) and CASI (3 m) imagery to scale point methane fluxes in a northern boreal landscape near Thompson, Manitoba. A sensitivity analysis showed that small hotspots of methane emission contribute the largest uncertainty in both remote sensing and field measurements. Methane emissions will tend to be underestimated in boreal landscapes due to the large variability in fluxes, sensitivity of wetland methane flux to small increases in temperature and precipitation, and because most remote sensing images do not adequately identify small areas of high methane emission. The magnitude of inter-annual variability in atmospheric carbon dioxide and methane exchange from peatland also varies among sites in peatlands, illustrated by results from a northern boreal and a cool temperate peatland.
Key words: peatlands, C cycling, CO2, CH4