Productivity of fodder areas according to Terra Modis data

Abstract

A quantitative assessment of the current state of natural fodder areas located in the Turano-Uyuk basin (Tuva) was made. Vegetation monitoring was carried out on the basis of Terra Modis satellite data by the following indicators: normalized vegetation index, gross primary production (GPP) and evapotranspiration. The productivity of plant associations was compared, their growth rate and the degree of GPP dependence on the sum of temperatures and evapotranspiration were determined. The results of ground-based studies performed by generally accepted methods were used for verifi cation. Remote indicators of gross production for the growing season ranged from 33.3 t/ha for halophytic meadows, and up to 48.8 t/ ha for wetland habitats. Depending on the species composition, gross productivity of glycophytic meadows during the growing season was 39.9– 48.7 t/ ha. A comparison of the data showed signifi cant differences in the remote and actual productivity of fodder areas, which can be leveled by means of correlation with the ground-based indicators. The best results of the relationship between gross primary production and the vegetation index with the sum of positive temperatures were identifi ed by polynomial equations of the third degree. The maximum period of phytomass development of natural fodder areas (meadow communities) was recorded before the beginning of June. Biological and environmental differences in the growth of vegetation during the season were noted in the period from 10-11 June to 19-20 July. The decrease in the accumulation of gross primary production by mid-July and the end of September was caused by weather conditions. The optimal grazing periods in the meadows in the Turano-Uyuk basin were determined.