Ontogenetic shifts in habitat-association of tree species in a neotropical wetland
Ontogenetic shifts in habitat-association of tree species in a neotropical wetland
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DOI：
10.1007/s11104-016-2844-y
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发表时间：
2016-07-01
期刊：
影响因子：
4.9
通讯作者：
Guimaraes Couto, E.
中科院分区：
文献类型：
--
作者：
Arieira, Julia;Penha, Jerry;Guimaraes Couto, E.
Aims我们评估了两个树的生活史阶段，年轻人和成年人之间的栖息地关联是否是一致的，以及空间梯度是否解释物种组成variation.Methods我们调查了栖息地关联的树组合使用多元回归树分析（MRT）。生境偏好进行了测定，使用指示种分析。我们解决了纯环境（即栖息地），空间结构化的环境和纯空间上的物种组成变化的贡献，使用部分冗余分析（pRDA）的变化分区。结果在植物个体发育过程中，生境联结性发生了变化。淹水深度解释了幼树阶段物种组成的差异。成木的分布格局可以用土壤肥力的空间变异来解释。纯空间对幼树群落变异的解释率（16%）高于生境（5%）.与此相反，成年树木的结构主要由栖息地（10%）。结论生态位扩张观察沿着树个体发育，与成年树木占据更广泛的洪水条件。纯空间对幼树分布的影响更大，突出了距离依赖过程（如扩散）对群落组成变化的重要性。大的原因不明的组件导致的变化分区表明，随机环境事件（如气候历史）可能有助于解释树组合动力学在潘塔纳尔系统。
Aims We evaluated whether habitat association is consistent between two tree life history stages, young and adult, and whether spatial gradients explain species composition variation.Methods We investigated habitat association of tree assemblages using multivariate regression tree analysis (MRT). Habitat preference was assayed using indicator species analysis. We addressed the contribution of pure environment (i.e. habitat), spatially structured environment and pure space on species composition variation using variation partitioning by partial redundancy analysis (pRDA). Principal coordinates of neighbor matrices (PCNM) were used to produce spatial regressors.Results Habitat association changed during plant ontogeny. Flooding depth explained differences in species composition at young tree stages. Distribution pattern of adult trees was explained by spatial variation in soil fertility. Pure space explained a higher fraction of community variability of young trees (16 %) than habitat (5 %). In contrast, adult trees were structured mostly by habitat (10 %).Conclusions Niche expansion was observed along tree ontogeny, with adult trees occupying a wider range of flooding conditions. The higher effect of pure space on young tree distribution highlights the importance of distance-dependent processes (e.g. dispersal) on the variation in community composition. The large unexplained component resulted from variation partitioning indicates that stochastic environmental events (e.g. climate histories) might contribute to explaining tree assemblage dynamics in the Pantanal system.