内蒙古锡林河流域羊草草原和大针茅草原在放牧影响下的分异和趋同

 在两个具有代表性的牧压梯度上，对羊草草原和大针茅草原的群落结构与牧压的关系借助模糊聚类的方法进行分析，揭示了不同牧压下植物群落的分异和不同群落在重牧压下的趋同，其总模式是：大针茅草原—持续牧压——→冷蒿草原 羊草草原—持续牧压———→冷蒿草原 把“群落趋同”的概念广延到放牧退化演替即次生逆向演替的生态学范畴。

THE DIVERGENCE AND CONVERGENCE OF ANEUROLEPIDIUM CHINENSE STEPPE AND STIPA GRANDIS STEPPE UNDER THE GRAZING INFLUENCE IN XILIN RIVER VALLEY,INNERMONGOLIA

Aneurolepidium chinense steppe and Stipa grandis steppe are two main community-types of the typical temperate semi-arid steppe in eastern part of the Eurasian continent al steppe region, widely distributed in the eastern part of the Mongolian plateau. Their structures are closely related to grazing pressure. This relationship was analysed based on two typical gradients of grazing pressure. The fuzzy cluster expressed the divergence of the similar communities under different grazing pressure and the convergence of the different communities under heavy grazing pressure, i.e., both Aneurolepidium chinense steppe and Stipa grandis steppe will change into Artemisia frigida steppe through the regressive succession if sustained grazing pressure is imposed.