石羊河中下游河岸植物多样性变化特征

摘要

采用Pielou均匀度指数、Margalef丰富度指数、Shannon-Wiener多样性指教,在海拔梯度上分析石羊河中下游河岸植物多样性的变化特征.结果表明,该区有4种植物群落类型,随着海拔(1 330～1 530m)的升高,其中3种多样性指数变化基本一致.呈降低→升高→降低的趋势;乔、灌木物种多样性受海拔变化影响较大,草本相对较小.红崖山水库以下,群落各层次的多样性特征指数为灌木层>乔木层>草本层;在水库以上,草木层>灌木层>乔木层.%The variation characteristics of riparian vegetation in middle and lower reaches of Shiyang River was studied using Pielou evenness index, Margalef richness index and Shannon-Wiener diversity index. There were four 4 plant community types in middle and lower reaches of Shiyang River. The variation trend of the 3 diversity indexes with the increase of elevation was the same, viz. decreased firstly, then increased, and decreased finally. The diversity of tree and shrub species were more influenced by elevation than herbal species. Diversity index of community at all layers was shrub-layer ＞ tree-layer ＞herb-layer below Hongyashan reservior. but herb-layer ＞ shrub-layer＞ tree-layer above Hongyashan reservoir.