Influence of Cattle Grazing Gradient on Plant Community Characteristics in Hulunber Meadow Steppe

The influence of cattle grazing gradient on plant community characteristics in Hulunber meadow steppe by grazing experiment was studied.The result showed that the tendency of height,coverage,density and biomass of plant communities were different in different seasons.The height and coverage decreased with the increase of grazing gradient;community density showed an increase-decrease-again increase trend with increasing of the grazing gradient.Community height was significantly decreased when stocking rate was higher than 0.46 Au/hm2,the height,coverage,density of plant community touched the bottom when the stocking rate was 0.69 Au/hm2.The appropriate grazing gradient of cattle during forage growing season was 0.00Au/hm2~0.46Au/hm2.Aboveground living biomass during the growing season showed low-high-low single-peak curve trend;with the increase in stocking rate,the peak value of the above-ground green biomass was decreased and the date of peak value was brought forward.Community height,coverage,density and aboveground living biomass throughout the grazing season were negatively correlated with grazing gradient.