Physical and ecological controls on methane release from a boreal peatland in interior Alaska
Dates
Year
2011
Citation
Shea, Kathleen M., 2011, Physical and ecological controls on methane release from a boreal peatland in interior Alaska: University of Guelph (Canada).
Summary
This thesis is an investigation of the biophysical controls on the three modes of methane (CH4 ) release from a boreal peatland: diffusion, plant-mediated transport and ebullition. My objectives were to (1) quantify the total CH4 flux of a permafrost thaw-affected peatland, (2) establish the relative importance of the three modes of CH4 release in these systems, and (3) identify key biotic and abiotic controls on individual transport mechanisms. Results showed that ebullition and plant-mediated transport were the dominant pathways for CH4 release and that traditional approaches for measuring total CH4 flux from peatland soils underestimated total efflux by not capturing ebullition. Further, results from a laboratory experiment indicated [...]
Summary
This thesis is an investigation of the biophysical controls on the three modes of methane (CH4 ) release from a boreal peatland: diffusion, plant-mediated transport and ebullition. My objectives were to (1) quantify the total CH4 flux of a permafrost thaw-affected peatland, (2) establish the relative importance of the three modes of CH4 release in these systems, and (3) identify key biotic and abiotic controls on individual transport mechanisms. Results showed that ebullition and plant-mediated transport were the dominant pathways for CH4 release and that traditional approaches for measuring total CH4 flux from peatland soils underestimated total efflux by not capturing ebullition. Further, results from a laboratory experiment indicated that ebullition is more sensitive to temperature than CH4 production. This study provides new understanding of controls on CH4 release pathways in peatlands, which will assist in the parameterization of biogeochemical models predicting high latitude greenhouse gas fluxes with climate change.
