Structure of phytomass of young trees of birch forests of nemoral grass

In article results of studying of a biodiversity of young trees of the birch forest are given in the Republic of Mari El. The age of forest stands was 37-39 years. During the work was determined the total biomass of plants, biomass and assimilating neassimiliruyuschih bodies as well as their ratio, the contribution of each population to the total mass, was carried occurrence score, determined the average height and diameter of the plants included in the regrowth. Made their recalculation for definition of characteristics of young trees, on platforms on 4 m2 two cross tape transects of 1 m of width. Analysis of the results showed that all of the undergrowth consists of a population of 9 species of woody plants: Betula pendula Roth., Ulmus laevis Pall, Quercus robur L., Picea х fennica (Regel) Kom., Acer platanoides L.), TÍlia cordáta Mill., Populus tremula L., Abies sibirica L., Pinus silvestris L.. The phytomass of young trees varies from 2.41 to 9.08 t/ha. Both the total phytomass and the mass of the assimilating and nonassimilative organs are positively correlated with the occurrence. The mass of assimilating organs of young trees is 11-14 times less than the nonassimilative ones. The greatest contribution to the total mass is made by the populations of TÍlia cordáta and Betula pendula.