Abstract
Climate change undermines the stability of natural ecosystems and adversely affects human life. Forest biocenoses can regulate the gas exchange of the atmosphere, accumulate and sequester carbon dioxide emissions, which are dangerous for the environment, in the phytomass components for a long time. The purpose of this study is to investigate the dynamics of bioproductivity of stands of the main forest-forming species of the Cheremsky Nature Reserve by components of phytomass and the carbon deposited in them. To solve the tasks of the study, the method of P.I. Lakyda was used. Experimental data of temporary trial plots, which fully characterize the forest massifs of the object under study, were used for modelling. The ratio coefficients Rv were calculated for stem wood (Rv(sw)); stem bark (Rv(sb)); branches (Rv(b)); leaves (needles) (Rv(l)). It was established that all above-ground components of Scots pine phytomass are described by regression equations. The coefficients of determination turned out to be insignificant, for the wood and bark of the stems of silver birch and common alder. In the structure of the phytomass of the forest stands of the reserve, the largest share (72.0%) falls on coniferous stands, a much smaller share – on soft-wood stands (26.0%) and the smallest – on hard-wood stands (2.0%). Over 13 years, the density of phytomass of stands and the carbon sequestered in it increased 1.4 times. Every year, forest biocenoses of the reserve release 6,989 tonnes of oxygen (4.2 t·ha-1) into the atmosphere. The main volume of oxygen (91.8%) is produced by coniferous stands. Based on the collected research material for stands of the main forest-forming species of the Cheremsky Nature Reserve, the following were calculated: ratios of above-ground phytomass components to their stock in the bark; mathematical models for evaluating the dynamics of phytomass components; standards for calculating oxygen productivity. The results of the study of the bio- and oxygen productivity of the forests of the Cheremsky Nature Reserve will be a significant contribution to effective management of the forest reserves, as well as to solving problems related to climate change at the regional and global levels