The impact of climatic changes on the vegetation cover of the intermountain basins of Tuva

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Abstract

The article considers the spatial and temporal variability of biological productivity indicators of steppe ecosystems in Tuva. It was found that the maximum supply of green phytomass, the amount of above-ground production and reserves of underground mortmass, spatial variability slightly exceeds the temporal one. It has been revealed that the productivity of the aboveground part of steppe communities is associated with favorable humidification climatic conditions. Minor changes in productivity indicators on pastures are associated with high grazing intensity, as well as with the resistance of dominants to grazing pastures. It was found that the indicator of green phytomass reserves varies to a lesser extent than the value of products. In recent years, underground production has undergone particularly drastic changes. An increase in the value of aboveground net primary production (ANP) is almost always accompanied by a decrease in the reserves of living underground plant organs (V), and often a decrease in the value of total underground production (BNP), which is associated with the peculiarities of the nitrogen cycle. The indicators of underground production are highly variable and do not correspond to the dynamics of terrestrial organs. The variability of the values of underground production is significantly higher than above-ground production. There is no direct relationship between the BNP value and climatic conditions. Despite the variety of methods for determining the parame-ters of phytomass production, their variability in space and time is approximately the same.