Assessment of the Influence of environmental factors on carbon stock in forest soils of Bryansk Poles’e

The search informative indicators of variation in soil carbon stock coniferous–broadleaf forest has a high predictive value. This article provides an assessment of the contribution of environmental factors to the variation of carbon stock in the forest soils. The study was carried out on the territory of the Bryansk Forest reserve on 45 sample plots located in different landscapes. Five groups of factors characterizing vegetation, macrofauna, landscape, relief, and history of environmental management were analyzed. Statistical relationships between carbon stock indicators and environmental factors were assessed using machine learning methods. The main factor determining the carbon stock in litter was the quality of litter, formed by the dominants of the trees, herbaceous and moss layers. Position in the landscape and other orographic characteristics were less informative. The highest carbon stock of the OL-subhorizon of the litter was in forests with a high proportion of pine. The most informative indicator for determining the variation in carbon stock FH-subhorizon of the litter was the projective cover of mosses. The results of regression analysis for the carbon stock in the A horizon and in the 0-30 cm layer demonstrated a significant contribution of indicators showing the increased hydromorphism, as well as characteristics connected with functional organization of forest ecosystems, namely the ecological-coenotic structure of plant communities (the proportion of nemoral species in the layer undergrowth and shrubs) and functional diversity of earthworms.