Carbon flow to acetate and C-1 compounds in northern wetlands

High latitude wetlands are significant sources of atmospheric methane, with emission rates that are susceptible to effects of climate change. Our data demonstrate that unlike mid-latitude wetlands, methane in northern peatlan ds is not derived from acetate or C-1 compounds. These latter compounds acc umulate to high levels with acetate as the primary organic end product of a naerobic decomposition. Acetate is ultimately degraded aerobically to carbo n dioxide after diffusion into oxic regions of peat. Therefore, organic pre cursors destined for methane in mid-latitude wetlands are degraded to carbo n dioxide in northern wetlands. A warming-induced initiation of acetoclasti c methanogenesis could substantially increase methane production.