围栏封育对草甸草原春秋放牧场草地物种多样性的影响

Effect of Enclosure Recovery on Species Diversity in Spring-autumn Grazing Grassland of Steppe Meadow

通过对新疆昭苏退化草甸草原春秋放牧场进行草地围栏样地设置与植被取样,群落α、β多样性指数分析表明:不同围栏年限对草地群落α多样性指数变化不同,即随着围栏年限的延长,群路丰富度指数呈倒"V"型变化,在围栏4α达到最大;优势度指数呈增大趋势;多样性指数和均匀度指数均呈减小趋势;群落β多样性相似性系数随着围栏年限的延长,相邻时段群落相似性系数增大,而与围栏外草地群落相似性降低。退化草地围栏修复进程与自然环境、种内种间竞争和修复时间有重要关系,因此适度围栏修复是草地健康持续发展的重要保障。

α and β diversity index of natural recovery with enclosure in spring-autumn grazing grassland of Zhaosu degraded steppe meadow were analyzed. The results showed that a diversity index varied with enclosure years. Community richness index changed in the type of opposition of V with the enclosure years lasting and got the highest at enclosure 4a. Dominance index showed a increasing trend, but diversity index and evenness index decreased. Community β simulation index at near periods increased with enclosure years,while reducing outside the enclosure. These were related to the fast enlarging and infringing of stipa population inside the enclosure which were dominant. The recovery progress of degraded grassland has a vital relation with natural environment, competition among species and individuals and recovery time. Thus enclosure recovery in modest level is vital to the healthy and consistent development of grassland.