Spatial variation in high‐latitude methane flux along a transect across Siberian and European tundra environments

Abstract

This paper reports results from a transect of methane flux measurements across tundra environments in Siberia and the European Arctic during July and August 1994. Overall, mean CH4 emission was 2.3±0.7 mg m−2 day−1 for the mesic tundra sites and 46.8±5.9 for the wet habitats with large intersite variability. The general scale of emissions was somewhat low compared to assumptions made about them in global methane budgets and models. In particular, the mesic tundra fluxes were lower than what would be expected based on data from similar environments in North America, and there are indications that these environments may be significant atmospheric methane consumers. Consistent consumption rates in combination with the large expanse of dry/mesic tundra environments suggest that it may be necessary to incorporate a high‐latitude soil sink term in global methane budgets. However, the wet tundra emissions found between 67° and 77°N in this study were consistently higher than recent findings in comparable environments at much lower latitudes (50°–55°N). High northern latitudes therefore represent a very important player in the global methane budget. When compared across both mesic and wet sites, methane emission increased with increasing soil organic content, soil temperature, and soil moisture. The relationship between soil temperature and methane flux at the wet sites alone was highly significant, and the flux also increased with increasing soil moisture and organic content. No correlations were found between flux and the measured environmental parameters at the mesic sites when treated separately.