Biological productivity of the naturally developing and disturbed by windfall lichen pine forest (Komi Republic)

The evidence characterizing the changes in the structural organization and productivity of the post-windfall middle-taiga lichen pine forest growing in the Northern Ural region are presented. It is shown that the stand after the windfall changes from a relatively uneven age with demutative phases of the dynamics of the age structure type to a conditionally uneven age. Pine undergrowth in both the background and disturbed areas is characterized as «healthy». It has been established that with an increase in the height of undergrowth, the number of individuals of the oppressed categories decreases. It was revealed that in naturally developing lichen pine forests of the same age, the morphometric indicators of trees (diameter, height), the reserves of organic matter of phytocenoses are higher than in post-windfall pine stand. A comparative analysis is made of the accumulation of the deposition of plant organic matter of naturally developing and post-windfall pine forests. Ten years after the windfall in the lichen pine forest, 91.8 t ha–1 of phytomass is concentrated, which is 1.4 times less than in the background pine forest. Ten years after the windfall, the bulk of organic matter is concentrated in large tree residues, whereas in naturally growing cenosis in growing trees, the annual production of phytomass of disturbed pine trees is 1.9 times less than in the background, makes up 1019 kg ha–1. The accumulation of phytomass production in the post-windfall lichen pine forest is equivalent to the role of woody plants and plants of ground cover, whereas in the background pine forest the main role is played by woody plants. It was revealed that after windfall there was a decrease in the participation of lichens and an increase in the participation of shrubs and mosses in the formation of ground cover. Annually, the decomposition constants of large wood residues in the windfall were 0.02 year–1