休牧后土壤养分空间异质性和植物群落α多样性

Spatial Heterogeneity of Soil Nutrients and α Diversity of Plant Community During Rest Grazing

分析了内蒙古温带典型草原休牧 4年后的草地土壤养分空间异质性和植物群落α多样性。结果表明 :休牧后 ,土壤养分的空间异质性呈不同程度的增大趋势 ,随机性因素所占比例增加 ;物种多样性指数和均匀度指数均有降低趋势 ,即群落物种多样性增加 ,均匀度降低。不同放牧率退化草地休牧过程中 ,植物群落的生物量、群落高度、群落盖度和群落物种多样性与土壤养分分布均表现一致的正相关关系 ,但只有植物群落生物量和群落高度与土壤有机碳、全氮、无机氮、土壤有效磷和有效硫相关性显著 (P <0 0 5 )。围封禁牧只是退化草地的一种利用方式 ,在围封一定时期后还要进行适度放牧或刈割 ,以保持草地植被的一定均匀度 ,防止 2次逆行演替发生。

In Inner Mongolia Steppe,the spatial heterogeneity of soil nutrients and α Diversity of plant community during rest grazing was studied in this paper .The results indicate: During rest grazing,heterogeneity of soil nutrients increased under different stocking rates,and the proportion of structure factors decreased.Diversity indices and evenness indices of plant species declined during rest grazing,which means that species diversity increased and evenness declined.Biomass,height,coverage and diversity of plant community have positive correlations with soil nutrients distribution,but only significant between biomass,height and soil organic C,total N,inorganic N,available P and S (P<0.05).Therefore,grazing prohibition is only a method of grassland utilization.After a certain period for grazing prohibition,the grassland should be used moderately to maintain certain evenness,and avoid regressive succession.