中文摘要：

以短花针茅荒漠草原植物种群为对象,对比分析自由放牧与禁牧（对照）区植物种群生态位宽度、生态位重叠、物种相对生态属性和物种生态响应。结果表明：与禁牧相比,自由放牧使建群种短花针茅和优势种无芒隐子草生态位变宽,而优势种碱韭生态位变窄。短花针茅、碱韭和无芒隐子草3个主要植物种群按相对衰退性排序与对照相反,且3个主要植物种群的生态属性均为衰退性植物种群。自由放牧对种群衰退性或发展性的相对排序及生态响应速率产生影响,致使种群生态位宽窄、生态位重叠程度发生变化。

英文摘要：

Taking Stipa breviflora desert steppe plant populations as the research object.A comparative study of the niche breadths,niche overlaps,species relative ecology properties and species ecological response of plant populations in the area of continuous grazing and banning grazing was performed.The results showed that：Compared with the banning grazing,continuous grazing broaden the niche of Stipa breviflora being constructive species and Cleistogenes songorica being dominant species and narrowed the niche of Allium polyrhizum being dominant species.The order of three main plant populations Stipa breviflora,Allium polyrhizum and Cleistogenes songorica was contrast to CK according to relative decline.The ecology property of three main plant populations was declining plant populations.Influence of continuous grazing on relative order of populations declining and developing leads to changes in niche width and degree of niche overlap.