Structure of woody debris of virgin spruce forests of the northern and southern taiga in the European part of Russia

Abstract

Woody decay is a multifunctional consort in the overall cycle of the substance and energy cycle of the forest community, taking an active and multifaceted part in the formation of structures and sustainability of forests. The age structures of forest stands, tree fallout, types of wood-destroying fungi and their infestation of forest stands were studied in indigenous virgin spruce forests of the subzones of the northern and southern taiga of the European Russia. The structures of virgin spruce forests have different dynamic characteristics, but they are always of absolutely uneven age. The affection of trees by fungi of the wood-destroying complex in the age generations of indigenous northern spruce forests increases from the last generations to the first and can reach 50–70 % of the number of trees in the generations. Rotten foots of tree trunks and roots in 80 % of cases are the causes of windfalls and windbreaks that shape the structure of the deadwood which is part of the total mass of the forest tree. In the studied spruce forests, the number of windbreak trunks is 2.6 to 3.8 times higher than windfall trunks. This is associated with a greater spread in the stands of rotten butt and stem parts of living trees than the number of rotten roots. The main types of wood-destroying fungi of the complexes of biotrophs and xylotrophs, which cause the decay of living trees and decompose the trunks of dead trees are determined. Wood decay amount runs to impressive figures from 12.5 to 35.0 %. The number, volume, phytomass of deadwood stems and the mass of СО2, Н2О and Q (energy) released during the decomposition of dead trees at the stages of decomposition in terms of 1 ha area of the analyzed spruce forests are calculated.

Keywords

• indigenous taiga spruce forests
• tree structure
• fallen trees
• wood-destroying fungi
• wood xylolysis