Methane (CH 4 ) flux measurements from Alaskan tundra bogs, an alpine fen, and a subarctic boreal marsh were obtained at field sites ranging from Prudhoe Bay on the coast of the Arctic Ocean to the Alaskan Range south of Fairbanks during August 1984. In the tundra, average CH 4 emission rates varied from 4.9 mg CH 4 m -2 d -1 (moist tundra) to 119 mg CH 4 m -2 d -1 (waterlogged tundra). Fluxes averaged 40 mg CH 4 m -2 d -1 from wet tussock meadows in the Brooks Range and 289 mg CH 4 m -2 d -1 from an alpine fen in the Alaskan Range. The boreal marsh had an average CH 4 emission rate of 106 mg CH 4 m -2 d -1 . Significant emissions were detected in tundra areas where peat temperatures were as low as 4°C and permafrost was only 25 cm below the ground surface. Emission rates from the 17 sites sampled were found to be logarithmically related to water levels at the sites. Extrapolation of our data to an estimate of the total annual CH 4 emission from all arctic and boreal wetlands suggests that these ecosystems are a major source of atmospheric CH 4 and could account for up to 23% of global CH 4 emissions from wetlands. DOI: 10.1111/j.1600-0889.1986.tb00083.x
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