The balance of the woody fraction of the indigenous spruce forests’ biomass in the European Russia’s taiga

Abstract

The study of the structural features of indigenous taiga’s woody fractions allows us to evaluate the balance process of accumulation and decomposition of woody biomass in forest communities. The purpose of the research is to study, using the example of European taiga’s spruce forests, the processes and organisms involved in forming the balance of biomass of woody fractions in indigenous ecosystems of different ages and with different dynamic characteristics. The research objects were located in the spruce forests of the northern, middle and southern taiga of European Russia. On permanent study plots (PSP), the diameters of trunks and the age of trees were determined, age series were put together by generations, and the total volumes of trees, forest stands and woody waste were calculated. Within the generations of the aforementioned age series and the forest stands overall, infestations by wood-decaying fungi (WDF) of biotrophic and xylotrophic complexes were determined. Indigenous spruce forests of the taiga have a complex multi-aged structure, differing in volume and trees infestation rate by WDF of the biotrophic complex within both the generations and the forest stands as a whole. It determines the different phase position of ecosystems. The trend of increasing tree infestation rate from younger to older generations is interpreted as a pattern. To calculate the balance of woody fractions biomass in a forest ecosystem, it is necessary to combine within a single time process the woody fractions of the forest stand and woody waste — dead wood and the current woody waste. The main factor in the formation of the biomass balance of a spruce community is the rate of wood accumulation and decomposition processes. In native spruce forests of different ages in the taiga zone, the rate of xylolysis of wood waste by WDF is several times higher than the rate of biomass accumulation in the forest stand. The balance of the biomass accumulation and decomposition processes intensity is presented as the balance coefficient of the spruce community’s woody fractions biomass, showing how much does the rate of the woody waste decomposition process performed by the xylotrophic complex fungi exceeds the rate of the biomass accumulation process in the living part of the forest stand. Possessing an enormous xylolytic activity, the WDF of the xylotrophic complex decompose woody waste at a rate exceeding the rate of woody biomass accumulation by the phytocenosis, thereby maintaining the balance of the biomass of the forest community and its stability.