南亚热带森林群落种-多度的对数正态分布模型研究

通过对地处南亚热带的广东省黑石顶自然保护区森林群落的定点研究结果的分析表明：当用１，２，３，…分组每种个体数ｒ时，５个不同类型的群落样地的种一多度分布的直方图都呈明显的倒Ｊ－形；经Ｐｒｅｓｔｏｎ“倍程（ｏｃｔａｖｅｓ）”法分组ｒ后，其种－多度都服从对数正态分布。由种－多度模型可以推出另一新的模型一个体一多度分布模型，即Ｉ（Ｒ）＝２R0ＳＯＥＸＰ［［１ｎ２）２／４ａ２〕ＥＸＰ｛－ａ２（Ｒ－（ＲＯ＋１ｎ２／２ａ２）］２｝，它也符合对数正态分布。另外，还运用积分方法推导出估计总体（整个群落）中总种数Ｓ*和总个体数Ｉ*理论值的公式，用此公式估计的结果较为合理。

Studies on log normal distribution patterns of species abundance of south subtropical forest community, China

Resesrch data of forest community in the permanent plots in Heishiding Nature Reserve,Fengkai County of Guangdong Province, are analysed. The results shown When' r' value (number ofindividuals every species) is divided into groups with l, 2, 3,.., species abundance distributionhistogram of each of five state quadrats (1600 square meters each) assumes inverted J-form. When' r' value is divided into groups with Preston's octaves method, species abundance distribution ofevery state quadrat is subordinated to log normal distribution Pattern. Moreover' a' value, one ofcoefficients of log normal distribution Pattern, is almost equal to 0.2. This Paper also deduces withintegral method the formula estimating theoretical value of total number of species (S*) and of individuals (I*) in population (that is, the whole community). The results calculated with the aboveformula are relatively reasonable. A conclusion is drawn that species abundance distribution of forest community in south subtropical area, China, abeys log normal distribution.