线叶嵩草草地群落构成及种间关联分析

以线叶嵩草群落和退化的线叶嵩草群落为对象,采用方差比率法分析群落总体关联性;基于2×2列联表及植物种重要值,运用χ2检验和Jaccard指数及Spearman秩相关分析,探讨了群落构成、植物种间关系及群落演替的阶段。结果表明:(1)2个群落物种组成差异小;(2)群落总体关联性均为显著负相关,群落种间关系整体上比较紧密;(3)群落内多数物种间联结性较弱,独立性较强,呈正相关和负相关的种对数约各占一半。研究认为,2个线叶嵩草群落均处于不稳定阶段。

Community Composition and Interspecific Association Analysis of Kobresia capillifolia Grassland

We firstly analyzed that the overall association characteristics of non-degraded and degraded Kobresia capillifolia communities by the variance ratio method.Then basing on 2×2 contingency table and important value of plant species,we investigated the composition of communities,interspecific relationship of plants and the stages of community succession,by using Chi square test,Jaccard index and Spearman rank correlation analysis.The results suggest that:(1)the differences in species composition between two communities are small;(2)the overall association of two communities shows significant negative correlation,and the interspecific relationship of each community are close on the whole;(3)most of the species of two communities have a weak interspecific association,namely,great independence,and the species pairs showing a negative or a positive association respectively occupies about half of total species pairs.It is studied that both non-degraded and degraded K.capillifolia communities are in the unstable stage.