湖南芷江县南方红豆杉群落特征及植物区系分析

Community characteristics and floristic analysis of Taxus chinensis var. mairei in Hunan Zhijiang

采用经典样方法对湖南芷江县南方红豆杉天然群落的种类组成、结构特征、物种多样性及植物区系等进行分析。结果表明:在1 000 m2样地中共有维管植物46科70属79种,其中蕨类植物5科7属8种,裸子植物2科2属2种,被子植物29科39属69种;群落分层明显,可划分为乔木层、灌木层和草本层;乔木层中有乔木树种17种,其中南方红豆杉和毛竹的重要值分别为81.51和43.37,远远超过其他的15种乔木树种,南方红豆杉的优势种群的作用明显,是群落的基调树种,毛竹为主要伴生种;灌木层包括乔木的幼树和灌木类,共40种;草本层植物有24种。物种多样性指数由高到低的顺序为灌木层>草本层>乔木层。植物区系地理成分复杂,科属组成均以热带性成分为主,温带成分占有较大的比例,反映出该群落植物区系由亚热带向暖温带过渡。

The species composition, structural characteristics, species diversity and plant flora of Taxus chinensis var. mairei natural communities in Hunan Zhijiang were analyzed using classical methods. The results showed that, there were 79 species of vascular plants in 1 000 m2 sample plot, belonging to 46 families and 70 genera, in which the bryophytes accounted for 5 families, 7 genera and 8 species, the gymnosperms for 2 families, 2 genera and 2 species, and the angiosperms for 29 families, 39 genera and 69 species. The structure clearly divided into tree layer, shrub layer and herb layer, there were 17 kinds of arbor in the tree layer, and the impor- tant values of Taxus chinensis var. mairei and Phyllostachys pubescens were 81.51 and 43.37 respectively, which were far more than other 15 kinds of arbor. The advantages of Taxus chinensis var. mairei populations was obvious, and it was the keynote of species com- munities, Phyllostachys pubescens as the main companion species. Shrub layer included trees saplings and shrubs, a total of 40 kinds, and there were 24 kinds of herb in herb layer. The species diversity index from high to low was shrub layer 〉 herb layer 〉 tree layer. The floristic geographical composition was complex, the floristie elements in the family and genera were mainly tropical elements with a certain proportion of temperate elements, which reflected the community flora transition from the subtropical to temperate.