Greenhouse Gas Fluxes and Carbon Sequestration in the Oligotrophic Peat Soils of Southern Taiga in Western Siberia

Abstract

The carbon stock and the emission rates of greenhouse gases (CO₂ and CH₄) in the peat soils of southern taiga in Western Siberia were studied. The studied peat soils belonged to typical oligotrophic peat soils (Histosols) but developed in two contrasting mire ecosystems—forested and open bogs—that differed considerably in the vegetation cover, soil morphology, and hydrological and temperature conditions. The carbon stock in the upper 50-cm-thick layer reached 9.3 and 6.8 kg/m² in the forested and open bogs, respectively. The CO₂ and CH₄ emissions were measured using a static chamber method during the growing seasons in 1999–2014. The CO₂ fluxes emitted from the studied soils into the atmosphere were close in their value (116.1 and 123.4 mg CO₂/(m² h) for the forested and open bogs, respectively), whereas CH₄ fluxes differed considerably (0.57 and 2.66 mg CO₄/(m² h), respectively). This study highlights an important role of the species composition and hydrological regime of peat soils forming in different bog ecosystems in the estimates of the carbon sequestration and greenhouse gas fluxes in the region.