围封对内蒙古希拉穆仁草地物种多样性的影响

Effects of Enclosure on Species Diversity in Xilamuren Grassland, Inner Mongolia

[目的]探究围封对内蒙古希拉穆仁草地物种多样性的影响,为围封对草原物种多样性影响的过程研究提供科学依据。[方法]通过调查、计算内蒙古希拉穆仁放牧草地与连续11 a围封草地的物种多样性,结合当地年降水量数据,分析放牧草地围封后物种多样性特征。[结果]围封后,冷蒿、轮叶委陵菜、达乌里芯芭、二裂委陵菜、星毛委陵菜年际波动较大;围封降低了希拉穆仁草地物种多样性,降水量较少年份(年降水量<200 mm的2014年)Simpson,Shannon-Wiener和Pielous指数则刚好相反;围封后物种丰富度与年降水量相关系数减小。[结论]长期围封导致希拉穆仁草地物种多样性下降。在干旱气候环境下,围封能够一定程度地缓解气候变化对希拉穆仁草地物种多样性的影响。

[Objective]The effects of enclosure on specie diversity of Xilamoren grassland in Inner Mongolia were studied in order to provide the scientific basis for the study of the grassland species diversity under the enclosure.[Medthods]This study analyzed the species diversity of enclosed grazing grassland based on the 11 years data of local annual precipitation in Inner Mongolia Autonomous Region.[Results]After enclosure,the interannual fluctuations of Artemisia frigida,Potentilla verticillaris,Cymbaria dahurica,Potentilla bifurca and Potentilla acaulis were larger.The diversity of the plants was reduced by the enclosure treatment.But Simpson ecological dominance index,Shannon-Wiener species diversity index and Pielous evenness index of the grassland plant in arid years were just the opposite in less precipitation years(2014 with annual precipitation less than 200 mm).Enclosure reduced the correlation coefficient between species richness and annual precipitation.[Conclusion]Enclosure treatment was not conducive to the plant diversity of Xilamuren grassland,but enclosure could alleviate the effects of climate change on species diversity under arid climate.