Effects of different grazing intensities on aboveground biomass and body weight of sheep on Alpine grasslands

In the present study, the impact of grazing on the aboveground biomass of alpine grasslands and the gaining effect of sheep were investigated.Tuoyun pasture was selected as a study area. Three grazing plots were set as treatment plots and a natural growth grasslands was set as the control plot. The results showed that 1) Tuoyun pasture is an alpine meadow with Leucopoa albida, Fescue arioides, Androsace umbellata and Oxytropis falcatae as the dominant species; 2) aboveground biomass of alpine grassland was very low, even in the prohibited graze area in July, and the aboveground biomass (dry matter) was merely 830 kgha-1; 3) grazing activities have a great impact on the aboveground biomass of the pasture, and heavy grazing can significantly reduce the aboveground biomass; 4) using the effect of liveweight gain as an evaluation index, a better weight gain was obtained under the stocking rates of 1 sheep unit (i.e. an ewe and a lamb) per hectare in this alpine pasture.