Methane Emission from Palsa Mires in Northeastern European Russia

Measurement data on methane fluxes in the palsa mire ecosystem at the border of tundra and taiga zones in northeastern European Russia are presented. It was found for the first time that an intense methane flux from the surface of the permafrost mound (palsa) is determined by the spring thawing of the seasonally thawed horizon in the layer of 14–25 cm. During this period, the emission was 4–20 times higher than the summer values. In lichen communities of peat mounds, the CH 4 sink prevailed during the summer-autumn period. The total methane flux in different parts of the mire in June–September varied from 0.18 to 16.5 kg CH 4 /ha. In general, the palsa mire emitted 81 kg CH 4 /ha per year to the atmosphere. The methane emission from the surface of peat mounds and hollows made up 20% and 80% of the annual flux, respectively.