不同载畜率对荒漠草原植物物种多样性的影响

he research of this paper is to select test area in Stipa breviflora desert steppe. By setting different stocking rate ,control area (CK). light containing stocking area (LG), moderate stocking area (MG) and severe stocking area (HG) .Using the Stipa breviflora desert steppe test area as the research object to research the different influence to desert steppe plant species diversity because of stocking rate. The stocking rates were 0. 0.91. 1.82 and 2.71 sheep units /hm2/ half a year. Each treatment was replicated three times . Grazing begin in June each year. Researching the different influence to desert steppe plant species diversity because of stocking rate systemically. The results were as follows: 1. The species richness was the largest in moderate grazing condition. This shows that the light stocking rate promote the plant species diversity in desert steppe. 2. Evenness index have a significant effect in different stocking rates. With the increasing of stocking rate. evenness index increased. 3. Shannon-wiener index first increased as the stocking decreased and then reduced. the control area is the highest. This shows that grazing condition is bad for desert steppe plant species diversity 4. Simpson diversity index in moderate stocking area is suited for desert steppe plant species diversity.