Habitat patterns in tropical rain forests: a comparison of 105 plots in northwest Borneo

Understanding the maintenance of high tropical tree species diversity requires disentangling the effects of habitat vs. geographic distance. Using floristic, topographic, and soil nutrient data from 105 0.6-ha plots in mixed dipterocarp forest throughout Sarawak, Malaysian Borneo, we explore the degree to which floristic patterns are habitat-driven from local to landscape scales. We assess how the floristic influence of geographic distance vs. abiotic factors varies from local to regional scales. We employ several multivariate analytical techniques and perform a hierarchical clustering of the research plots using the Steinhaus index of floristic dissimilarity, as well as Mantel analyses on matrices of floristic, habitat, and geographic distance. These analyses indicate that floristic variation is more strongly correlated with habitat than with geographic distance on the regional scale. On the local-landscape to community scale, we find evidence of a resource threshold above which habita...

阐明生境与地理距离的影响差异，是揭示热带树木高物种多样性维持机制的核心任务。本研究利用马来西亚婆罗洲沙捞越地区全境混交龙脑香林内105块面积为0.6公顷的样地的植物区系、地形及土壤养分数据，探究从局地到景观尺度下，植物区系格局在多大程度上由生境驱动。本研究同时评估从局地到区域尺度，地理距离与非生物因子对植物区系组成的影响强度如何变化。研究采用多种多元分析方法：基于植物区系相异度的斯坦豪斯（Steinhaus）指数对研究样地开展层级聚类，并针对植物区系、生境及地理距离矩阵进行曼特尔（Mantel）分析。结果表明，在区域尺度上，植物区系变异与生境的相关性显著强于其与地理距离的相关性。在局地-景观至群落尺度上，本研究发现存在某一资源阈值，当生境条件高于该阈值时……