短期休牧对克氏针茅草原植物群落物种多样性及稳定性影响研究

Effects of short-term exclusion grazing on the species diversity and stability of Stipa krylovii steppe plant communities

文章采用野外植物样方采取及实验室数据分析相结合的方法,以阿巴嘎旗北部牧户常年放牧和隔年休牧的冬季草场为例,探讨短期休牧对克氏针茅草原植物物种多样性及群落稳定性的影响。结论如下:(1)两个草场植物群落内植物数量差异不大,主要差异表现在主要植物的平均重要值及两个草场仅有2对共优种。此外,短期休牧冬季草场的禾本科植物比重提升的同时,一年生藜科植物也显著提升;(2)短期休牧冬季草场的植物群落物种多样性指数略高于常年放牧冬季草场,但差异不显著;(3)两个草场植物群落处于中等相似水平,植物种间存在分异化趋势;(4)短期休牧冬季草场植物群落总体呈微弱正联结,种间联结松散,处于正向演替阶段,常年放牧冬季草场呈微弱负相关,群落较不稳定,存在一定退化风险;(5)两个草场的植物群落离稳定性都有一定差距,但短期休牧冬季草场植物群落稳定性略好于常年放牧冬季草场。可见,短期休牧有利于克氏针茅草原植物群落物种多样性和稳定性保持。

In this paper,the all-year-round and short-term exclusion grazing winter pastures of herdsmen in the northern part of Abaga banner were taken as an example,combination of field plant sample and laboratory data analysis which were used to investigate the species diversity and the impact of community stability of Stipa krylovii steppe. The conclusions were as follows:(1)There was no significant difference in the number of plants in the plant communities of the two pastures,but the difference in the average value of the main plants was significant. There were only 2 pairs of common species in the two pastures. When the proportion of gramineous plants in grassland was increased,the annual plant of the genus polygonaceae was also significantly improved;(2)The plant community species diversity index of short-term exclusion grazing winter pasture was slightly higher than that of perennial grazing winter pasture,but the difference was not significant;(3)The plant communities of the two pastures were at moderately similar levels,and there was a trend of differentiation between plant species;(4)The plant communities in the short-term exclusion grazing winter grassland were weakly positively connected,the interspecific linkages were loose,and they were in the positive succession stage. The perennial grazing winter grassland was weakly negatively correlated,the community was unstable,and there was a certain risk of degradation;(5)There was a certain gap between the stability of the plant communities in the two pastures,but the stability of the plant communities in the short-term exclusion grazing winter pasture was slightly better than that in the perennial grazing winter pasture. Short-term exclusion grazing was conducive to the species diversity and stability of the plant communities in the grassland of Stipa krylovii.