Importance of topography and soil texture in the spatial distribution of two sympatric dipterocarp trees in a Bornean rainforest
Importance of topography and soil texture in the spatial distribution of two sympatric dipterocarp trees in a Bornean rainforest
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DOI：
10.1046/j.1440-1703.2003.00556.x
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发表时间：
2003-05-01
影响因子：
2
通讯作者：
Lee, HS
中科院分区：
文献类型：
--
作者：
Itoh, A;Yamakura, T;Lee, HS
分析了东马来西亚沙捞越热带雨林中两种同属挺水树——香龙脑香树和龙脑香科——空间分布和立地条件（即地形和土壤质地）之间的关系。一块 52 公顷的永久地块被划分为 1300 个 20 m x 20 m 的样方；对于每个鳞茎树种，d.b.h 大于或等于 1 cm 的树木数量和总断面积。对不同场地条件的样方组之间进行比较。由于鳞木和立地条件变量的空间分布是聚合的，因此应用蒙特卡罗排列检验来分析这些关系。单因素和多因素统计检验均表明，这两个物种的密度和断面积分布与土壤质地和地形变量的关系显着非随机。在较高海拔、沙质土壤以及凸坡和陡坡上，芳香果的数量明显增多。相比之下，D. lanceolata 更喜欢较低的海拔和较少的沙质土壤。在研究样地中，只有极少数地点（测试的 1150 个样方中的 3 个）使用 Hayashi 方法的模型预测了两个物种的共现。这些结果表明，物种间栖息地偏好差异如此之大，以至于仅靠它们就可以解释这两个物种在 52 公顷研究地块内的空间隔离分布。
Relationships between spatial distributions and site conditions, namely topography and soil texture, were analyzed for two congeneric emergent trees, Dryobalanops aromatica and Dryobalanops lanceolata (Dipterocarpaceae), in a tropical rainforest in Sarawak, East Malaysia. A 52-ha permanent plot was divided into 1300 quadrats measuring 20 m x 20 m; for each Dryobalanops species, the number and total basal area of trees greater than or equal to1 cm in d.b.h. were compared among groups of quadrats with different site conditions. Because spatial distributions of both Dryobalanops and site-condition variables were aggregated, Monte-Carlo permutation tests were applied to analyze the relationships. Both single and multifactor statistical tests showed that the density and basal area distributions of the two species were significantly non-random in relation to soil texture and topographic variables. D. aromatica was significantly more abundant at higher elevations, in sandy soils, and on convex and steep slopes. In contrast, D. lanceolata preferred lower elevations and less sandy soils. In the study plot, there were very few sites (3 of 1150 quadrats tested) where the models of Hayashi's method predicted the co-occurrence of the two species. These results suggest that between-species differences in habitat preferences are so large that they alone explain the spatially segregated distributions of these two species within the 52-ha study plot.