锡林河流域草原植物群落多样性沿海拔梯度变化特征

摘要

以锡林河流域草地植被为研究对象,采用物种重要值,α、β多样性指数对流域植物群落多样性沿海拔梯度分布特征进行研究.结果表明:在各海拔梯度内羊草均占优势地位.随着海拔梯度的升高,α多样性指数均呈现先降低后升高的变化趋势;在影响Simpson多样性指数的程度上,丰富度指数高于均匀度指数.随着海拔梯度的升高,β多样性指数具有先降低后升高再降低的变化趋势.在海拔梯度1200 m~1300 m与1300 m~1400 m之间群落物种相似度较高,物种更替速率较慢;在海拔梯度1100 m~1200 m与1200 m~1300 m之间群落物种组成差异性较大,物种更替速率较快.%Based on the grassland vegetation in the Xilin River Basin , the species importance values , andα,βdiversity index were used to study the distribution of plant community diversity along the altitudinal gradi -ent .At each altitude gradient , Leymus chinensis was dominated .With the increase of the altitude gradient ,αdi-versity index trended to decrease first and then increase .To the affected extent of Simpson diversity index , the richness index was higher than the evenness index .With the increase of the elevation gradient ,βdiversity index trended to decrease first and then increase , then decrease again .The species had high similarity between 1200 m and 1300 m, and between 1300 m and 1400 m altitudinal gradient .The species replacement rate was slow.At the altitude gradient of 1100 m~1200 m and 1200 m~1300 m, the species composition had distinct difference , and the species replacement rate was rapid .