The phytomass of plant communities of the highlands of Tuva

The research objective was the identification of the plant communities’ phytomass which plays a role in the landscape structure of Tuva alpine belt. The investigations were carried out in July-August 2002-2013 on sixteen grounds located in a moun-tain belt of seven large mountain systems of Tuva (the array Mongun-Taiga, ridges Tsagan-Shibeta, Western and East Tannu-Ola, Ulan-Tayga, the Academician Obruchev and Uplands Sangilen). The accounting of aboveground phytomass was carried out by the method of hay crops from the platform of 0.25 m2 in size, in five- and tenfold fre-quency. It was shown that the total phytomass stocks varied widely in the formations groups: 2445.9 to 6970.8 g/m2. The total phytomass of shrub tundra occupied in average of 6970.8 g/m2, shrub, lichen and grass occupied 2445.9-2904.4 g/m2. An intermediate position was occupied by sub-alpine and alpine meadows (3925.9-4792.4 g/m2). It was revealed that the total biomass of 57.6-69.9 %, and depended on the value of stocks above and below ground biomass. The group formations among the shrub tundra and alpine meadows traced the de-cline aboveground biomass stocks shrub, low shrubs, mosses and lichens, sedges opposite sig-nificantly increased biomass of grasses and forbs. The ratio of vascular and spore plant average var-ied from 2.4 to 3.4. The stocks aboveground of mortmass varied between 158.3-619.4 g/m2. Un-derground phytomass of tundra and grassland communities was 1840.4-4948.1 g/m2, of which the share of the participation of biomass was 57.8-72.0. The distribution of underground plant organs revealed marked attraction to the upper layer of soil depth of 0-10 cm (85.5-97.6).