滨海自然植物群落物种多样性及种间垂直联结性

Species Diversity and Inter-specific Association between Vertical Layers in Coastal Natural Plant Communities

关键词:  滨海地区  植物群落  物种多样性  垂直层次  优势种  种间联结

Key words:  coastal zone  plant communities  species diversity  vertical layers  dominant species  inter-specific association

摘要:

通过对滨海植物群落物种多样性和种间联结性研究，探索群落的形成及种间的共生与竞争关系，为滨海沙地和海岛修复的树种选择与配置提供理论依据。以广西防城港市滨海自然植物群落为对象，研究其群落结构、物种多样性及垂直层次间物种的联结性与相关性。结果表明：广西防城港滨海自然森林群落组成复杂，物种丰富，分层比较明显，大致可分为乔木层（含乔木层和亚乔木层）、灌木层和草本层。各物种丰富度指数（S）、Shannon-Wiener指数（H'）、Simpson指数（D）和Pielou均匀度指数（J_sw）均表现为灌木层 > 乔木层 > 草本层，三者变化趋势较为一致，草本层处于退化状态；χ²统计量、种间关联系数AC和物种共同出现百分率PC检验结果表明，乔木层与亚乔木层物种总体存在显著负联结，相互独立的种对较多，较少种对显著联结；乔木层与灌木层物种总体存在显著正联结，显著联结的种对较多，种对间较紧密；亚乔木层与灌木层物种间总体存在显著负联结，处于不稳定的演替阶段。表明群落内垂直层次间物种相似的生境要求、生态习性，以及在垂直方向上对生境要求的互补性差异是导致种对间关系的主要原因。

Abstract:

Through the study of species diversity and inter-specific association of coastal plant communities, the formation of communities and the symbiotic and competitive relationship between species were explored, which provided a theoretical basis for the selection and allocation of tree species for coastal sandy land and island restoration. The coastal natural plant community in Fangchenggang City of Guangxi Province was taken as object, and the community structure, species diversity and the association and correlation of species between vertical layers were studied. The results show that the coastal natural forest community of Fangchenggang in Guangxi has complex composition, abundant species and obvious stratification. It can be roughly divided into tree layer (including tree and sub-tree layers), shrub layer and herb layer. The species richness index (S),Shannon-Wiener index (H'),Simpson diversity index (D) and Pielou evenness index (J_sw) were all expressed as shrub layer > tree and sub-tree layers > herb layer. The variation trend of species diversity index was consistent with the variation trend of richness index. The herb layer was in a state of degradation. The results of χ² tests, inter-species association coefficient (AC) and percentage co-occurrence (PC) showed that there was significant negative association between tree layer and sub-tree layer, while there were more independent species pairs, and fewer pairs were significantly connected. There was a significant positive association between the species in tree layer and shrub layer, and there were more pairs of species that were significantly connected, and the species pairs were much closer. Generally there was a significant negative association between the species in sub-tree layer and shrub layer, which was in an unstable stage of succession. The results suggested that similar habitat requirements and ecological habits of species between vertical levels within a community and complementary differences in habitat requirements between the vertical layers might be the main driver affecting the relationship between species.