The article summarizes data from studies of the ecosystem exchange of carbon dioxide and methane emissions in a meso-oligotrophic bog and a palsa mire in North-East European Russia, which differed in topography, plant cover structure, air and soil temperature regimes, and duration of the growing season. The study is based on the results of measurements by using the eddy-covariance and the static chamber methods during the growing season. Differences were detected in the rate and duration of CO₂ sink between the two ecosystems. The total net CO₂ exchange during the snowless period was 450 g/m² in the meso-oligotrophic bog, and 150 g/m² in the palsa mire. The cumulative methane flux in the palsa mire ecosystem was half that of the meso-oligotrophic bog due to the presence of permafrost soils. Herb-dominated hollows were the main sources of methane in the peatlands.