How will a warming climate effect the trace gas fluxes on the Arctic tundra?
The Arctic tundra is a major source and sink of carbon-containing gases, but the biogeochemical cycling of halocarbons in this ecosystem has been largely unexplored. Between 2005-2008, we measured coastal tundra fluxes of methyl halides (CH3Cl, CH3Br, and CH3I), chloroform (CHCl3) and methane (CH4) near Barrow (71° N, 157° W) and Toolik Lake, Alaska (68°38’N, 149°38’W). We found that the Arctic tundra, unlike temperate wetlands, was an overall SINK for methyl bromide and methyl chloride rather than a SOURCE. This sink was related to hydrologic conditions (drier tundra meant more uptake) and was large enough to constitute a regionally significant sink for these compounds (Rhew et al., 2007; Teh et al, submitted). We also discovered that the Arctic tundra is a potentially globally significant source of atmospheric chloroform, a finding that we attribute to the peat accumulation in the wet tundra and the chlorination of organic humic and fulvic acids. Additional research has been conducte
