STRUCTURE AND REGULARITIES OF THE DEVELOPMENT OF FOREST STANDS WITH OAK REPRESENTS IN MARI EL REPUBLIC
The research is urged by the necessity to improve forest management in oak stands, which constitute less than 1 % of the total forested area in the Russian Federation and keep decreasing under negative natural and anthropogenic factors. The research is aimed at evaluating the contemporary condition of forest stands with English oak (Quercus robur L.) represents in the forested area of the Mari El Republic, thus, revealing the regularities of its development. The research is meant for improving forest management activities in oak forest. Methods of research. For the purpose of our research we referred to e-database which contains inventory data from over 400 stratums with the total area of 1,165,628 ha. In order to process data we used the mathematical statistics method and appropriate software. Research results. The paper presents data on the structure and regularities of the development of forest stands with oak represents in Mari El Republic. The data are provided in tables, mathematical equations and graphs. The data show that the area and share of oak plantations depend on the location and the forestry enterprise, which is the result of soil and environmental conditions of the area and particularities of forest management activities. Forest stands in Mari El Republic with oak represents, aged 250 years, with the quality class varying from 1 to 5 and density varying from 0.3 to 1.0 are mainly complex in contents representing 4-5 species. The density of oak population is particularly high in site type С<sub>3</sub> и D<sub>2, </sub>where it reaches 6.81 and 25.3 % correspondingly. Other TLU feature miniscule share of oak density which varies from 0.01 to 0.17. With the growth of the forest stand containing oak, there is a certain transformation of the species composition and fluctuation of the parameters of condition. The increase of oak density results in stem wood reduction. The wood stands composed of 4 species with 30 % oak presence proved to be the most productive. We may conclude that oak stands do not fulfill their production capacity to the full. In order to improve it is necessary to improve forest management techniques and optimize the species composition of the forest stands.