贡嘎山国家级自然保护区多鳞杜鹃群落结构及其多样性特征

Community structure and diversity characteristics of Rhododendron polylepis in Gongga Mountain National Nature Reserve

为保护中国特有种多鳞杜鹃,调查了多鳞杜鹃群落的生境状况、物种组成、生活组成、结构特点和物种多样性分析。结果表明,多鳞杜鹃分布范围广,分布在海拔1 800 m~3 200 m区域,为林内生态幅度较宽的植被类型。三个不同海拔梯度多鳞杜鹃群落共分布22科、35属、47种植物。多鳞杜鹃有多种生活型植物组成,其中以高位芽植物和地上芽植物为主,从垂直结构看,多鳞杜鹃群落分布有乔、灌、草层,分层现象明显,多鳞杜鹃和丰实箭竹为灌木层优势种。多鳞杜鹃群落以草本层的生物多样性最高,在高海拔区域乔木层的优势种明显随海拔降低呈降低趋势。不同海拔梯度下多鳞杜鹃群落各项多样性指数表明多鳞杜鹃群落各层次的物种丰富度指数、多样性指数、优势度指数、均匀度指数均表现出草本层>灌木层>乔木层一致性特征。物种多样性与物种丰富度成正比,物种多样性越高代表群落稳定性越好。

In order to protect Rhododendron polylepis,an endemic species in China,the habitat condition,species composition,life composition,structural characteristics and species diversity of R.polylepis were investigated.The results showed that R.polylepis distributed widely,ranging from 1800 m to 3200 m above sea level,and it was a vegetation type with wide ecological range in the forest.There were 47 species of Rhododendrons belonging to 35 genera and 22 families in three different elevations.R.polylepis was composed of many life-form plants,among which high-bud plants and aboveground-bud plants were the dominant ones.From the perspective of vertical structure,R.polylepis community was distributed in the tree layer,shrub layer,and herbaceous layer,and the stratification phenomenon was obvious.R.polylepis and Fargesia ferax were the dominant species in the shrub layer.The biodiversity of R.polylepis community was the highest in the herbaceous layer,and the dominant species in the tree layer in the high altitude area showed a decreasing trend with the decrease of altitude.The species richness index,diversity index,dominance index and evenness index of R.polylepis community at different elevations showed the identical feature:herbaceous layer>shrub layer>tree layer.There was a postive relationship between species diversity and species richness.The higher the species diversity,the better the community stability.