湖南三道坑自然保护区珍稀濒危植物鹅掌楸群落的研究

Study on Community of Rare and Endangered Plant Liriodendron chinense in Sandaokeng Nature Reserve, Hunan Province

摘要:

采用5个物种多样性指数对湖南三道坑自然保护区珍稀濒危植物鹅掌楸（Liriodendron chinense（Hemsl．）Sarg．）群落进行物种多样性测定，并分析了群落的种类组成、外貌、演替等。结果表明：（1）群落垂直结构明显，可分为乔木层、灌木层、草本层、地被层。共有维管束植物76种，隶属48科57属。群落生活型谱以高位芽植物占优势（68.42％），与其它亚热带常绿落叶阔叶林相似。（2）群落的物种多样性高，灌木层的各项物种多样性指数均高于乔木层和草本层。整个群落的丰富度高达76；Simpson指数D为0.9516，接近D_max；Shannon-Wiener指数H为3.3247：基于Simpson指数的均匀度指数J_s为0.5843，而基于Shannon-Wiener指数的均匀度指数J_sw为0.8826。（3）从鹅掌楸种群的生势衰退和数量削减以及幼龄个体的贫乏来看，目前这个群落已处于发育过程的衰老阶段。

Abstract:

The community of Liriodendron chinense in Sandaokeng Nature Reserve in Hunan Province was investigated using several species diversity indices. Floristic composition, physiognomy, species diversity and the possible succession of the community were analyzed. The results indicated that the vertical structure of the com- munity was obvious, which composed of tree, shrub, herb and ground layers. There were 76 vascular plant species in the community belonging to 48 families and 57 genera. Phanerophytes （accounted for 68.42%） were dominant in the life-form spectrum, which was similar to that in subtropical evergreen and deciduous broad-leaved forest. The community had very high species diversity. Species diversity indices in shrub layer were higher than that in tree layer and herb layer. Richness index of the community was 76. Simpson index D was 0.9516, which was close to the maximum of D; Shannon-Weiner index H was 3.3247. Evenness index based on Simpson index J_s was 0.5843, and that based on the Shannon-Weiner index J_sw was 0.8826. Because of the decline of growth potential and quantitative decrease in population, as well as deficiency in young seedlings, the community of Liriodendron chinense is now at the senescence phase.