ESTABLISHMENT AND DYNAMICS OF SPECIES COMPOSITION IN PINE WOOD OF MARI ZAVOLZHIE

Abstract

The research is carried out in response to the need of enhancing the environmental and resource capacity of forest by means of optimization of their species composition. The work is aimed at perception of regularities of establishment and development of stand species composition in pinewood of Mari Zavolzhie and representing them in the form of mathematical models. The focus of research is the forest growing in different hydrotopes of the pine range. For the purpose of the current research we used e-database containing stand data from over 78,000 plots with the total area of 385,184 ha. In order to solve the set task the authors used well-tested computer-aided technology based on system statistical analysis of digital information using standard application packages. As a result of research it has been found out that tree composition is unique in every hydrotope with the general prevalence of pine trees, the number of which is particularly high in dry fresh pine woods. The most intense struggle for the living space occurs between the tree species in humid and wet pinewoods, in which there is a prevalence of birch and presence of aspen and spruce. Representation of all tree species in establishment of forest structure varies considerably. In terms of composition, only pine woods are pure. Their share is particularly large in dry and bogged pinewoods, where there a weak competition for the living space between the species due to tough environment. The share of pine trees in humid and wet pinewoods varies. Birch is often widely represented in such stands. Species composition of forests significantly changes with aging. Every hydrotope features its own specific species composition, with gradual increase of pine share in each of them. Conclusion. It is necessary to catty out thinning operations in young forest of 1-2 age classes in wet pinewoods. The analysis of tree composition dynamics carried out based on the data from mass inventory of plantations proved the conclusions drawn by other researchers, grounded on field examination of stand species composition, thus complementing them by mathematical models and considerably expanding the age limits of biogeocenose development.