Effects of grazing on community characteristics of alpine meadow on the northern shore of Qinghai Lake, China

A three year grazing trial was conducted in a two seasonal grazing (warm-season and cold-season) pasture in alpine meadow to study the variations of the plant community characteristics in the warm-season pasture and winter pasture. In the two seasonal grazing pasture, the aboveground biomass of plant communities decreased with grazing intensity increasing, and the aboveground biomass of graminoid had similar performance with plant community. The influence of grazing treatments in warm-season pasture was higher than that in winter pasture. The dominant plant species under no grazing, heavy grazing in cold-season pasture were Stipa purpurea and Kobresia humilis, whereas the dominant species under the other grazing treatments were S. purpurea and Thermopsis lanceolata. The diversity index and evenness index of the plant community in warm-season pasture firstly decreased and then increase with grazing intensity increasing, however, these two indices of the plant community in cold-season pasture increased with grazing intensity increasing. For warm-season pasture and cold-season pasture, the diversity index was the highest under heavy grazing intensity.