STRUCTURAL AND ECOLOGICAL FEATURES OF BROADLEAF FORESTS OF THE SUBTAIGA SUBZONE IN THE NORTH-WEST OF TATARSTAN

The article is devoted to the formation of modern phytocoenoses of broadleaf and small­leaved­broad­leaved forests in the subtaiga subzone of the European Russia on the site of the previously existing coniferous and coniferous­broadleaf forests. The article shows the results of detailed geobotanical and silvicultural studies of deciduous forests of different rock composition, which were carried out on trial plots in the Precamsky regions of Tatarstan. In particular, species richness and specific saturation of communities, quantitative participation of species of different tiers, stands’ species composition, stock of individual breeds and peculiarities of their renewal are analyzed. An assessment of the conditions for the growth of forest phytocoenoses was carried out on the basis of the ratio of the species of different ecological­coenotic groups. Presently the vegetation of the studied area is represented by long­term and settled­secondary plant communities of lime­birch, birch­linden and linden­oak forests, which have arisen as a result of economic activity, as well as due to climate changes. In communities with a predominance of lime over a period of more than 60 years, there was a decrease in oak stocks, as well as an increase in the share of meadow species of plants (up to 25 %). Nevertheless, broadleaf forests of the hemiboreal strip in the north­west of Tatarstan retain a complex of ecological­coenotic features, which are caused by zonal and historical conditions. At the same time, the distribution of coniferous and deciduous forests occurs in the subtaiga subzone. The obtained data can serve as a basis for monitoring the transformation of forest vegetation in the zone of taiga contact, broad­leaved forests and forest­steppes.