Carbon stock in litter of middle taiga forest ecosystems of Central Siberia

Litter plays an important role in the carbon cycle of forest ecosystems incorporating significant amount of carbon as a result of annual partial die-off of the biomass and releasing it during complex multistage processes of organic matter decomposition. The balance of these processes in the forests of permafrost zone significantly shifts towards the accumulation of dead organic matter. That makes the assessment of litter stock in these ecosystems particularly relevant, especially in relation to the predicted consequences of climate change in the study region. On the territory of middle taiga of Central Siberia, 14 sampling plots were established in the various landforms (slopes of different exposition, lowlands and uplands). The carbon stock in litter of the main forest types of the studied area varied from 0.47 to 4.46 kgC/m 2 . Also, the paper considers composition of litter accumulated in these ecosystems, including the ratio between fresh litterfall, fermented and humified plant residues, and dead roots. Our results demonstrated that fermented plant residues prevailed in the litter composition in most types of studied forest ecosystems due to specificity of hydrothermal regime and quality of litterfall. The results obtained might be applied to refine the carbon budget of Siberian forests.