黔西北地区不同杜鹃灌丛群落特征和物种多样性

Characteristics and species diversity of different Rhododendron shrub communities in northwest Guizhou

为探明黔西北地区不同杜鹃灌丛群落特征和物种多样性变化,本研究以5个不同的杜鹃群落为研究对象,分析了物种组成、重要值和多样性指数。结果表明,5个群落共有33种植物,属16科23属,灌木层和草本层分别有27种和6种;优势种和共优势种植物分别为小果珍珠花、小果珍珠花+露珠杜鹃、小果珍珠花+露珠杜鹃、露珠杜鹃、露珠杜鹃+黄山杜鹃。5个杜鹃灌丛群落灌木层的α多样性指数差异明显,灌木层的Margalef丰富度指数、Simpson多样性指数均表现为露珠杜鹃+黄山杜鹃灌丛群落(V)最大,小果珍珠花灌丛群落(I)最小;Shannon-Wiener多样性指数和Pielou均匀度指数均表现为小果珍珠花+露珠杜鹃灌丛群落(II)最大,小果珍珠花灌丛群落(I)最小。露珠杜鹃+黄山杜鹃灌丛群落(V)有进一步演替为亚热带常绿阔叶林的趋势。杜鹃属植物覆盖度大的临近群落的Whittaker指数、Jaccard指数和Sorenson指数值均较覆盖度小的临近群落大。

In order to investigate the community characteristics and species diversity changes of Rhododendron shrub in different communities in northwest Guizhou Province,the species composition,importance value and diversity index of 5 Rhododendron communities were analyzed.The results showed that there were 33 species belonging to 23 genera,16 families,27 species in shrub layer and 6 species in herb layer,respectively.The dominant species of five Rhododendron shrubs were Lyonia ovalifolia,Lyonia ovalifolia and Rhododendron irroratum,Lyonia ovalifolia and Rhododendron irroratum,Rhododendron irroratum,Rhododendron irroratum and Rhododendron maculiferum.Theαdiversity index of shrub layer was significantly different among the five Rhododendron shrub communities.The Margalef richness index and Simpson diversity index of shrub layer were the largest in Rhododendron irroratum+Rhododendron maculiferum shrub community(V),and the smallest diversity index was present in Lyonia ovalifolia shrub community(I).Shannon-Wiener diversity index and Pielou evenness index had the largest values in Lyonia ovalifolia+Rhododendron irroratum shrub community(II),while the Lyonia ovalifolia shrub community(I)was the smallest.The Rhododendron irroratum+Rhododendron maculiferum shrub community(V)had a tendency of evolving into subtropical evergreen broad-leaved forest.The values of Whittaker index,Jaccard index and Sorenson index of adjacent communities with high coverage of Rhododendron plants were higher than those of adjacent communities with low coverage.