珠穆朗玛峰国家级自然保护区高山杜鹃群落多样性研究

根据野外样方调查数据,采用双向种指示分析(TWINSPAN)和典范对应分析(DCCA),对珠穆朗玛峰国家级自然保护区高山杜鹃灌丛群落进行分类和排序,并分析物种多样性沿海拔梯度分布格局。结果表明:(1)该研究区域38个高山杜鹃样地中,共记载的维管束植物有35科68属135种,出现频度较高的种有高山嵩草(Kobresia pygmaea)、珠芽蓼(Polygonum viviparum)、高山大戟(Euphorbia stracheyi)、髯花杜鹃(Rhododendron anthopogon)、雪层杜鹃(R.nivale)、扫帚岩须(Cassiope fastigiata)、鳞腺杜鹃(R.lepidotum)、木根香青(Anaphalis xylorhiza)、刚毛杜鹃(R.setosum)等。(2)TWINSPAN等级分类将该区域高山杜鹃灌丛38个样地划分为14个群丛类型。(3)样地DCCA二维排序图结果表明,土壤类型和海拔是影响该区域高山杜鹃灌丛群落分布格局的主要因子。(4)该区域高山杜鹃灌丛群落物种丰富度、Shannon-Wiener指数和Simpson指数与海拔呈显著负相关关系,随着海拔的升高而不断降低;而Pielou指数与海拔之间并无显著相关关系。

Community Diversity of Alpine Rhododendron in Qomolangma National Nature Reserve

Based on field survey data,we studied classification and ordination of Alpine rhododendron community by the methods of TWINSPAN and DCCA,and analyzed distribution pattern of species diversity along the elevation gradient in Qomolangma National Nature Reserve.The results showed that:(1)38 plots included 135 species vascular plants in this Nature Reserve,belonging to 68 genera and 35 families,respectively.The most prevalent species were Kobresia pygmaea,Polygonum viviparum,Euphorbia stracheyi,Rhododendron anthopogon,R.nivale,Cassiope fastigiata,R.lepidotum,Anaphalis xylorhiza and R.setosum.(2)38 plots of alpine rhododendron community were classified into 14 types of plant association.(3)According to two-dimensional DCCA ordination diagram,the soil type and altitude are the main factors of affecting distribution pattern of Alpine rhododendron community in this area.(4)Species richness S,Shannon Wiener index and Simpson index of Alpine rhododendron community declined significantly along the altitude gradient,but there is no significant correlation between Pielou index and altitude in this area.