中文摘要：

采用样方法对内蒙古典型草原区围封27年（E27）、7年（E7）、1年割1次（M）和中度放牧（G）样地的群落物种多样性、群落高度、群落密度、地上生物量进行实地调查分析,以研究不同干扰对典型草原群落物种多样性和生物量的影响。结果表明,围封27年和中度放牧样地的丰富度指数、多样性指数、均匀度指数仍显著高于围封7年和1年割1次样地,但围封27年样地与中度放牧样地之间无显著差异,围封27年和中度放牧相对于围封7年和1年割1次可以维持群落物种多样性;1年割1次和中度放牧样地退化指示植物糙隐子草重要值显著高于围封样地,草原群落呈退化趋势;围封7年样地的地上现存量为454.06 g/m^2,显著高于其他样地。说明围封7年可显著提高草原生产力,但围封时间过长将不利于其维持较高的生产力。

英文摘要：

Effect of different disturbances on species aboveground biomass of the typical steppe was inves vised in the study area, including moderately grazed and exclosure for 27 year were significantly higher G. So, E27 and G might tlgat （G） diversity, community height, community density ed by quadrant method. Four treatment plots were de , mowing once a year （M）, exclosure for 7 year （E7） （E27） plots. The richness index, diversity index and evenness index in the E22 and G than those in the E7 and M, but there is no significantly difference between E27 and maintain community species diversity. The important values of.the indicator plant of degradation （Cleistogenes squarrosa） in M and G plots were significantly higher than that of the exclosure plots. The above ground biomass of E7 was 454.06 g/m^2 ,and significantly higher than that of the other plots. Thus, E7 could significantly increase the steppe productivity, but there would be no help-for the steppe productivity if exclosure lasts too long.