PhD Oral Defense: Surface to Atmosphere Carbon Exchange in Peatlands with Permanent Open Water Pools
PhD Oral Defense of Luc Pelletier, Department of Naural Resource Sciences
Peatland ecosystems are long-term net carbon (C) sinks but the open water pools that are characteristic of these temperate to subarctic wetlands have been found to be C sources to the atmosphere. Their contribution to the ecosystem level C budget has often been ignored even if they cover a significant area of the peatland surface. There is therefore a question as to whether peatlands containing pools are smaller net sinks of atmospheric C compared to peatlands without pools; the total C loss measured from pools is the same order of magnitude, but with the opposite sign, as the published average net ecosystem carbon balance for pool-free northern peatlands. In this study, I evaluated the annual C release from peatland open water pools, its impact on the net ecosystem carbon dioxide exchange (NEE-CO2) and assessed the NEE-CO2 variability and controls on between peatlands with different pool cover.