Tropical Rain Forest Biodiversity Analyzed by a Large Research Plot

热带雨林的物种丰富度进行了分析，通过使用一个大规模的研究地块，其中有一个大小为52公顷，并于1993年建立在Lambir国家公园，沙捞越，马来西亚。本文主要对生态位理论中的平衡假说和非平衡假说在解释热带雨林生物多样性作用机制中的有效性进行了检验。通过将整个地块面积划分为1300，20 mx20 m的立场，四个地形和五个森林结构变量进行了计算，为1300个立场。地形变量表明，陡峭的斜坡，急剧起伏，复杂的平分地形的阴谋。森林结构变量也表明了一个巨大而复杂的结构与重叠的森林层。地形和结构变量高度相关，表明森林结构与地形的可预测性。在5个林分结构变量中，20 m × 20 m林分每层平均胸径随每层林木密度的增加而减小，表现出单株林木生长的密度依赖性。样地的总物种数为1175种，远高于马来西亚西部Pasoh的物种数（820种/50公顷）和巴拿马的BCI物种数（306种/50公顷）。一些优势种的空间格局与地形因子也有很强的相关性。所有这些结果表明，可预测的变化的巨大和复杂的结构的雨林在兰比尔，似乎是有利的平衡假说作为一个工作机制的热带生物多样性。通过分析叶片同工酶谱来研究遗传多样性，暗示基因漂移对于产生丰富的热带生物多样性的重要性。

The species richness of a tropical rain forest was analyzed by using a large-scale research plot, which has a size of 52 ha and was established at the Lambir National Park, Sarawak, Malaysia in 1993. Questionnaires of the present study are mainly concerned with the tests of availability of two contrasting hypotheses, equilibrium hyporthesis (niche theory) and non-equilibrium hypothesis, for the explanations of working mechanisms of the biodiversity of tropical rain forest. By dividing the whole plot area into 1300,20mx20m stands, four topographic and five forest-structural variables were calculated for each of 1300 stands. The topographic variables suggested the steeply sloped, sharply undulating, and complexly bisected topography of the plot. The forest structural variables also suggested a huge and complex structure with superimposed forest layrs. Both topographic and structural variables were highly correlative, suggesting a predictability of forest structure with respect to topography. Out of the five forest structural variables, mean dbh per forest layr in a 20mx20m stand decreased with and increase of tree density per forest layr, showing a density dependency of individual tree growth. The total number of species in the plot was 1175, which was far greater than those at Pasoh (820 spp/50ha) in west Malaysia and BCI (306) spp/50ha) in Panama. The spatial patterns of some dominant species were also highly correlative with topographic variables. All these results suggested the predictable change of the huge and complex architecture of the rain forest at Lambir and seemed to be favored by the equilibrium hypothesis as a working mechanism of tropical biodiversity. The genetic diversity was studied by analyzing isozyme patterns in leaves and implied the importance of gene drifts for producing the rich tropical biodiversity.