论文部分内容阅读
在瓦屋山定位研究了中亚热带湿性常绿阔叶林次生群落 1 5a来各乔木种群组成及其重要值、密度、大小结构、高度结构和材积生产力等的动态变化。结果表明 :自然恢复过程中次生常绿阔叶林群落乔木层物种组成变化明显 ,有 1 1种从群落乔木层消失 ,也有 1 0种出现 ,乔木层树种多样性 (丰富度 )基本保持动态平衡和发展 ;优势种地位保持不变 ,但次优势种地位得以加强 ;群落结构变化较大 ,突出表现为种群密度、胸径和树高分布格局的变化和立体空间的分化 ,群落由单优或双优种向双优或多优势种发展 ,由单一乔木层向多层次立体结构发展 ,空间加厚 ,群落更复杂、稳定性增强。乔木种群平均高生长速度在 2 4～ 4 8cm·a-1,平均DBH生长率在 0 34～ 1 1 0cm·a-1,各种群生长速度差异明显 ,按生长速度可划分为适应性强的速生树种如细梗吴茱萸叶五加 ,华木荷 (平均DBH生长在 0 70cm·a-1以上 ) ,中等速度的小叶青冈、扁刺栲 (平均DBH生长在 0 4 0cm·a-1以上 ) ,慢生种如润楠 ,石栎 (平均DBH生长在 0 4cm·a-1以下 ) ;种群材积生产力高低不一 ,优势种扁刺栲种群材积生产力并不是一直增长 ,而是在后期出现下降 ;次优势种增长速度较快。1 997年 3固定样地材积量 2 1 8～ 2 35m3·hm-2 ,优势种群材积生产力是群落材积生
In Wawushan, the dynamics of population composition, density, size structure, height structure and yield capacity of various tree species in subtropical wet-leaved evergreen broad-leaved forest secondary communities after 1 5 years were studied. The results showed that the species composition of arborous layer in secondary evergreen broad-leaved forest changed significantly during natural restoration. There were 11 kinds of tree species disappeared from the community and 10 species appeared, and the species diversity (richness) of arbor layer kept the same Balance and development. The dominance of dominant species remained unchanged, but the dominant position of sub-dominant species was strengthened. The community structure changed greatly, which manifested the change of population density, DBH and tree height distribution and the spatial differentiation. Double-superior species to the double superior or multi-dominant species development, from a single layer of trees to the development of multi-level three-dimensional structure, space thickening, the community more complex, enhanced stability. The average growth rate of arbor population was 24-480 cm-1, and the average growth rate of DBH was 0 34-1 110 cm-1. The growth rate of each group differed significantly. According to the growth rate, Of fast-growing species, such as fine stem Evodia falciparum, Hua Muhe (average DBH growth in more than 0 70cm · a-1), moderate velvety Cyclobalanopsis glauca, flat thorn 栲 (average DBH growth in more than 0 0 cm · a-1 ), Slow-growing species such as Run Nan and Quercus acutissima (average DBH growth below 0 4cm · a-1). The productivity of population volume varied from low to high. The yield productivity of dominant species was not always increasing, but appeared later Decline; sub-dominant species grow faster. In 1997, the volume of fixed plots was 2 1 8 ~ 2 35m3 · hm-2,