Habitat divergence in sympatric Fagaceae tree species of a tropical montane forest in northern Thailand
Habitat divergence in sympatric Fagaceae tree species of a tropical montane forest in northern Thailand
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DOI：
10.1017/s0266467407004403
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发表时间：
2007-08
影响因子：
1.4
通讯作者：
Hideyuki Noguchi;A. Itoh;T. Mizuno;Kriangsak Sri-ngernyuang;M. Kanzaki;S. Teejuntuk;Witchaphart Sungpalee-Witchapha
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文献类型：
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作者：
Hideyuki Noguchi;A. Itoh;T. Mizuno;Kriangsak Sri-ngernyuang;M. Kanzaki;S. Teejuntuk;Witchaphart Sungpalee-Witchapha
许多热带树木的空间分布偏向于特定的生境，即生境专化。然而，特殊物种的生境必须是不同的，即生境分歧，在当地社区共存。当一对物种在同一生境中特化，即生境趋同时，它们不能通过生境特化共存。因此，除了生境特化外，还需要对生境分化进行分析，以探讨同域种的共存机制。在这项研究中，栖息地专业化和栖息地分歧沿着地形梯度的8个同域树种的壳斗科进行了研究，在一个15公顷的研究地块在泰国北方的热带低山地森林。9673株壳斗科树木的环面移位随机化的统计检验显示，所有物种的分布显着偏置，至少有一个四个地形变量：海拔，坡度，方面和凸度。坡度凸度是最关键的地形变量，沿沿着，但一个物种有显着的偏态分布。在112个可能的种对和地形变量组合中，分别有18个（16%）和2个（1.8%）表现出明显的生境分化和生境趋同。单凭栖息地的差异并不能完全解释这8个物种的共存。每个物种的栖息地位置都有一个层次，分布在相似栖息地的物种之间有较大的重叠，而与对比栖息地相关的物种之间的重叠较小。物种栖息地的逐渐变化表明，将物种分为少数不同的栖息地群体，如山脊和山谷专家，并不简单。
Spatial distributions of many tropical trees are skewed to specific habitats, i.e. habitat specialization. However, habitats of specialist species must be divergent, i.e. habitat divergence, to coexist in a local community. When a pair of species specialize in the same habitat, i.e. habitat convergence, they could not coexist by way of habitat specialization. Thus, analyses of habitat divergence, in addition to habitat specialization, are necessary to discuss coexistence mechanisms of sympatric species. In this study, the habitat specialization and habitat divergence along topographic gradients of eight sympatric tree species of the Fagaceae were studied in a 15-ha study plot in a tropical lower montane forest in northern Thailand. A statistical test with torus shift randomizations for 9673 trees of Fagaceae revealed significantly biased distributions for all of the species, for at least one of the four topographic variables used: elevation, slope inclination, aspect and convexity. Slope convexity was the most critical topographic variable, along which all but one species had significantly skewed distributions. Out of 112 possible combinations of species pairs and topographic variables, 18 (16%) and two pairs (1.8%) showed significant habitat divergence and habitat convergence, respectively. The observed habitat divergence alone could not completely explain the coexistence of the eight species. There was a gradation in the habitat position of each species, with relatively large overlaps between species distributed in similar habitats, and small overlaps between species associated with contrasting habitats, respectively. The gradual changes in the habitats of the species suggested that dividing the species into a small number of distinct habitat groups, such as ridge and valley specialists, would not be straightforward.