关键词: 围栏封育, 围栏放牧, 植物群落特征, 荒漠草原

Abstract: In order to reveal the effects of enclosure and grazing on plant communities in the desert steppe and find the way of conservation and utilization of desert steppe,three pairs of enclosed grasslands and grazing grasslands were selected in the desert steppe of Yanchi County,Ningxia,to investigate the planting community. The selected area was the sierozem soil and aeolian sandy soil land with the same topography,soil and vegetation conditions. Based on the sample survey,the diversity characteristics of the plant community were analyzed using the diversity index. The results showed that at the species level,the perennial grasses were mainly dominated on the sierozem soil,and the annuals and biennials were the dominant community on the aeolian sandy soil. The species composition in the enclosed grassland tended to be stable,while the grazing grassland community was still in the early stage of unstable succession. Fence enclosure was conducive to improving the biomass,height and coverage of plant communities in desert steppe;the growth of plants on sierozem soil was significantly higher than that on aeolian sandy soil. In the desert steppe with relatively few plant species,the grazing prohibition changed the species structure of community,but it did not significantly increase the diversity;it was beneficial to improve the species diversity on the aeolian sandy soil. Compared to grazing treatment,enclosure was more conducive to maintaining the stability of the ecosystem in the region.

Key words: Enclosure, Grazing, Plant community characteristics, Desert steppe