PHYTOMASS HERACLEUM SOSNOWSKYI AND THE RATE OF ITS DECOMPOSITION IN THE SOILS OF POSTAGROGENIC ECOSYSTEMS OF THE MIDDLE TAIGA SUBZONE OF THE KOMI REPUBLIC

The dynamics of decomposition of Heracleum sosnowskyi and dominant plant species of a grass meadow in a laboratory experiment is considered. Samples of the humus-accumulative horizon of the postagrogenic sod-podzolic soil of the Komi Republic were used as a substrate, the exposure time was 75 days, the ambient temperature was +5 ° C, the substrate humidity was 60% of the total moisture capacity of the soil. It is shown that under the controlled experimental conditions, various parts of Heracleum sosnowskyi plants lose up to 43-44% of the initial dry phytomass during the exposure period, and meadow cereals – up to 18-29%. The main part of the loss of phytomass falls on the first 28 days of exposure. For the aboveground part of plants, it is 70-78% of the total loss of plant mass, for the underground part of plants – 47-51%.