COMPARATIVE ASSESSMENT OF THE SUCCESSION DYNAMICS OF WOOD FRACTIONS OF SPRUCE FORESTS OF THE SOUTHERN TAIGA

Relevance. The native forests can be recognized as endangered formations of the European North of Russia. They are benchmarks of forest sustainability for comparative assessment with forests of other origin and use, what determines the relevance of research on their structural features. The purpose of the research is to conduct a comparative assessment of dynamic processes in the native forests of spruce formations of the southern taiga subzone of various successional positions (phases of dynamics) in the time trend of their development. Material and methods. Native spruce forests of different ages of the southern taiga subzone of the Central Forest Biosphere Reserve (Tver region) and the Kologrivsky Forest Reserve (Kostroma region) were researched various dynamic characteristics and successional position — climax, demutation, digressive. In the biogeocenoses of the sample areas, the age of trees and the presence of rot were determined, age series were built, the volumes of trees in age generations were calculated. All the tree fractions of the analyzed spruce forests were arranged in one time series: stands, current tree fall and deadfall — from retrospective values (– 60 years) to prospective values of the age limit of trees of the first generations of stands (+ ~ 300 years). The processes of dynamics of volumes of the wood fraction of native spruce forests of various successional positions in a long time space with different rates of accumulation and decomposition of wood biomass are described. Results and discussion. The processes of accumulation of biomass and the formation of age structures of biogeocenosis are 4 to 7 times slower than the processes of decomposition of the dying biomass of woody decay. Wood-destroying fungi of the saprotrophic complex “adjust” the activity of the decomposition process of wood decay to the dynamics of wood accumulation by the stand, maintaining the balance of accumulation and decomposition of woody biomass in the forest community. The correlation dependence of the increase in the values of tree infestation with wood-destroying fungi in age generations with an increase in their age is expressed in correlation coefficients from r — 0.89 at mr — 0.07 and t — 11.8 (spruce grove 1) to 0.99 at mr — 0.004 and t — 245 (spruce grove 4). The connection in both cases is very high, almost functional, which can be interpreted as a pattern. Conclusion. In native virgin forests, the balance of reproducible and decomposable wood is preserved as one of the most important criteria for the sustainable functioning of forest communities. This position can be regarded as an important fact of the evolutionary functional structure of forests.