广州白云山次生常绿阔叶林的群落结构动态

根据对广州白云山次生常绿阔叶林群落相隔６ａ的两次植被调查，分析了广州白云山次生常绿阔叶林在保护条件下，自然演变过程中的群落结构动态．群落的垂直结构变化主要以大量幼树进入第一层成树为特点；水平结构则以密度和盖度的增长为特点．在种类组成方面，６ａ前群落中居多的阳性树种现已逐渐为耐阴性较强的种类所代替．在组织结构水平上，乔木层的物种多样性指数、群落均匀度指标趋于增加，而生态优势度指标趋于降低，反映了群落向着组成结构复杂、物种多样性增高的方面演变，且前期变化速度较快，后期较慢并趋于稳定．

DYNAMICS OF COMMUNITY STRUCTURE OF A SECONDARY EVERGREEN BROADLEAVED FOREST IN BAIYUNSHAN OF GUANGZHOU

Based on the vegetation investigations twice in six years on a secondary evergreen broadleaved forest in Baiyunshan of Guangzhou,the community structure dynamics in natural succession process of the forest under protection was studied.In vertical structure,a large number of young trees became mature in the first layer of the community.In horizontal structure, forest density and community coverage increased.As for the speific compeition,the dominant species were changed from heliophytes to mesophytes after six years. The speices diversity and community evenness increased, but the ecological dominance tended downwards. The communitier sradually became complicated in composition and diversified in species, and the chanses took place fast in former stage and slower in later stage,and finally tended to be stable.