舟山群岛典型植物群落物种组成及多样性

Floristic composition and diversity of typical plant community in Zhoushan Archipelago,East China

以舟山群岛特有树种普陀樟(Cinnamomum japonicum var.chenii)、舟山新木姜子(Neolitsea sericea)和全缘冬青(Ilex integra)等占优势的植物群落为研究对象,通过典型样地调查,对物种组成及多样性进行了研究。结果表明:7个植物群落共调查到维管束植物125种,隶属于62科100属,其中滨海特有植物有12科14属16种。地理成分多样,热带成分大于温带、亚热带成分。各层次优势种明显,乔木层主要有红楠(Machilus thunbergii)、普陀樟、全缘冬青和舟山新木姜子等,在更新层中普陀樟和红楠最具优势,而灌木层、草本层、藤本层的优势种取决于群落类型及其所处的环境。群落间各层次的物种丰富度指数(R),Shannon指数(H),Pielou指数(J)均有较大波动,一般与群落的演替阶段、所处岛屿的大小、离大陆远近以及人为干扰有关,其中R、H保持一致的变化趋势。舟山海岛最具代表性的普陀樟群落各层次的R、H均低于其他群落。

The species composition and diversity of communities dominated by endemic species Cinnamomum japonicum var. chenii, Neolitsea sericea and Ilex integra in Zhoushan Archipelago were studied based on the investigation of typical plots. A total of 125 species of vascular plants, belonging to 62 families and 100 genera in seven plant communities were recorded. Among them, 16 endemic species to oceanfront belonging to 12 families and 14 genera were observed. The geographical elements were various, while tropical elements outweithed the temperate and subtropical elements. The dominant species were obvious in each layer. Species were dominated by Machilus thunbergii, C. japonicum var. chenii, I. integra and N. sericea in arborous layer, and by M. thunbergii and C. japonicum var. chenii in regeneration layer. The dominant species in shrub layer, herb layer and liana layer depended on community type and the environment. There was a large fluctuation of species richness （R）, Shannon index （H） and Pielou index （J） between different layers of plant communities, which was related to the successional stage of community, the size of island, the distance from island to land, and human disturbance. The R and H indexes showed a consistent pattern of change trend. The R and H indexes in each layer of typical C. japonicum var. chenii community in Zhoushan were lower than those of other communities.