Topography and neighborhood crowding can interact to shape species growth and distribution in a diverse Amazonian forest
Topography and neighborhood crowding can interact to shape species growth and distribution in a diverse Amazonian forest
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DOI：
10.1002/ecy.2441
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发表时间：
2018-10-01
期刊：
影响因子：
4.8
通讯作者：
Kraft, Nathan J. B.
中科院分区：
文献类型：
--
作者：
Fortunel, Claire;Lasky, Jesse R.;Kraft, Nathan J. B.
非生物的限制和生物的相互作用同时作用，以塑造社区。然而，这些社区组装机制往往是独立研究，这可能会限制了解它们如何相互作用，影响物种动态和分布。我们开发了一个分层贝叶斯邻域建模方法，以量化的同时影响的地形和拥挤的邻居的124,704个单独的茎1cm胸径的1,047热带树种在25公顷的映射在亚马逊厄瓜多尔雨林地块的增长。我们建立多层次的回归模型，以评估四个关键的功能性状（比叶面积，最大树的大小，木材比重和种子质量）介导树木生长的地形和邻里拥挤的反应。树木在山谷中的生长速度比在山脊上快，并且由于邻里拥挤而减少。地形和拥挤的相互作用，影响树木生长在类似的10%的物种。比叶面积，最大树的大小和种子质量与地形的生长反应，但不与邻里拥挤或地形和拥挤之间的相互作用的反应。总之，我们的研究表明，地形和邻里拥挤的热带森林中的树木生长的影响，但在很大程度上独立地塑造物种分布。虽然性状与物种对地形的反应有关，但它们在物种对邻域拥挤的反应中的作用不太清楚，这表明性状对邻域动态的影响可能取决于生物相互作用的方向（负/正）和对称程度。我们的研究强调了同时评估在高多样性热带系统中塑造物种动态的多种机制的个体和互动作用的重要性。
Abiotic constraints and biotic interactions act simultaneously to shape communities. However, these community assembly mechanisms are often studied independently, which can limit understanding of how they interact to affect species dynamics and distributions. We develop a hierarchical Bayesian neighborhood modeling approach to quantify the simultaneous effects of topography and crowding by neighbors on the growth of 124,704 individual stems 1cm DBH for 1,047 tropical tree species in a 25-ha mapped rainforest plot in Amazonian Ecuador. We build multi-level regression models to evaluate how four key functional traits (specific leaf area, maximum tree size, wood specific gravity and seed mass) mediate tree growth response to topography and neighborhood crowding. Tree growth is faster in valleys than on ridges and is reduced by neighborhood crowding. Topography and crowding interact to influence tree growth in similar to 10% of the species. Specific leaf area, maximum tree size and seed mass are associated with growth responses to topography, but not with responses to neighborhood crowding or with the interaction between topography and crowding. In sum, our study reveals that topography and neighborhood crowding each influence tree growth in tropical forests, but act largely independently in shaping species distributions. While traits were associated with species response to topography, their role in species response to neighborhood crowding was less clear, which suggests that trait effects on neighborhood dynamics may depend on the direction (negative/positive) and degree of symmetry of biotic interactions. Our study emphasizes the importance of simultaneously assessing the individual and interactive role of multiple mechanisms in shaping species dynamics in high diversity tropical systems.