Changes of Vegetation Characteristics in Alpine Meadow-steppe of Eastern Qilian Mountains after Different Grazing Rest Modes

Effects of different grazing rest modes on plant community characteristics and underground biomass of alpine meadow-steppe were investigated in Eastern Qilian Mountains.The three grazing treatments were traditional grazing(TG),grazing rest in growing stage(RG)and non-grazing(NG).The results indicated that the height of gramineous,leguminous,sedge and forbs plant functional groups increased,aboveground and belowground biomass of gramineous plants,and the dominant gramineous plant important values of Elymus nutans were all increased with grazing ceasing of RG or NG,especially obvious with NG.However,the important values and the ratio in aboveground and underground community biomass of forbs were all decreased.The Shannon-Wiener index(H),Pielou evenness index(J),richness index(S)and total density of plant community are in an order of NGTGRG.The non-grazing improved the biomass,and reduced the biodiversity simultaneously.Therefore,grazing rest is one of the main way to improve production ability and ecological rehabilitation for degraded grassland.