PERENNIAL MONITORING OF A PASTURE DEPRESSION DEVELOPMENT UNDER DIFFERENT LOADS OF THE TERSKO-KUMSKAYA LOWLAND

Changes in phytocenoses in the long-term regime under the influence of anthropogenic pressure, natural and climatic factors are considered. Under the conditions of growing external influence the ordinary components of the community are transformed into its dominant synanthropic forms. Geobotanical studies have shown the heterogeneity of the vegetation cover of pastures in terms of phytocenotic composition, which is in a state of severe disruption. The long-term monitoring studies of pastures show that a complex of environmental factors has a significant impact on the change in species composition and structure under various loads. Change in the vegetation cover under the influence of weak grazing is disappearance of large-sod grasses of the Stipa series with a predominance of small-sod grasses such as Festuca sulcata. Intensive grazing causes disappearance of Festuca sulcata, as well as appearance of small Artemisia shrubs and more competitive plant species that cause changes in plant communities. Such changes make it possible to determine the dominant plant species, during the development of which the next transition of penetration into plant communities of other species begins. The phytocenoses of the compared species of this region differ in the structure and productivity of the dominant forage plants which give the highest phytomass depending on the humidity of the period and the type of load. The purpose of this work is to show the long-term influence of climatic factors in the absence of a minimum of atmospheric precipitation, as well as anthropogenic influences on the transformation of phytocenoses, changes in the structure of the vegetation cover of the semi-desert at different stages of loading. The article presents research data for several years on the species composition and productivity of pastures, depending on the load by the seasons of the year. The results of monitoring studies have established the number of dominant species and their productivity of phytocenoses at different stages of development of vegetation degradation.