关键词: “S”型曲线规律, “S”型曲线规律

Abstract:

In order to guide the production and use local naturally grassland reasonably, an assessment was conducted on grassland primary production and livestock carrying capacity in Maqu County, Gansu. By used the materials from field investigation on Maqu County of Gansu Province and MODIS images of remote sensing, the carried capacities on theory and seasonal ranges were compared and analyzed based on calculated grassland yields and grazing capacities and grassland ranking was conducted in this paper. The general results of study indicated, the main reasons that led to change on grassland productions of Maqu County were excessive grazing livestock and natural climate conditions such as increasing temperature, decreasing annual precipitation which brought about inadequate rainfall on arid grassland. The reverse tend of change on carrying capacities caused the reduction of grassland productions, and natural climate conditions led to the desertion of grassland in some extents. Consequently, the carrying capacities must be strictly controlled and the practically grazing capacities should be set based on the new theoretical and critical carrying capacity in order to turn back the reverse tend of grazing capacity and eliminate the reduction of grassland productions.