Climatic and geographic correlates of global forest tree species-abundance distributions and community evenness.
Climatic and geographic correlates of global forest tree species-abundance distributions and community evenness.
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全球森林树种丰度分布和群落均匀度的气候和地理相关性。
DOI：
10.1111/jvs.12346
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发表时间：
2016
影响因子：
2.8
通讯作者：
Shiono T. & Kubota Y.
中科院分区：
文献类型：
--
作者：
Ulrich W.;Kusumoto B.;Shiono T. & Kubota Y.
问题物种-丰度分布(SADS)长期以来一直是生态学研究的中心，因为它们以浓缩的形式总结了群落聚集的各种模式。在这里，我们将观测到的SAD形状和均匀度模式与纬度和气候条件联系起来，以推断全球物种丰度分布的全球趋势。定位全球方法我们汇编了来自全球605个地点的树木物种丰度和气候协变量的数据。将对数序列和对数正态分布的线性回归模型和非线性最小二乘拟合法应用于物种排序对数丰度图，以评估物种丰度分布和Pielou均匀度的纬度和气候梯度。结果即使在考虑丰富度和空间效应后，我们仍观察到SAD形状和均匀度的显著纬向趋势。均匀度有向低纬方向增加的趋势，与实际蒸散量呈正相关，与气候变率呈负相关。我们观察到低纬地区的对数序列SADS过剩，而北纬地区的对数正态分布有所增加。相应地，从对数系列分布中不如预期的物种比例向热带方向下降。结论我们推测，观察到的纬度趋势是由于扩散对当地乔木群落聚集的重要性的不同梯度造成的。这一解释意味着，与温带社区相比，热带社区往往更开放和更受投入驱动。
QuestionsSpecies–abundance distributions (SADs) have long been at the centre of ecological interest because they summarize various patterns of community assembly in condensed form. Here we link observed patterns of SAD shape and evenness to latitude and climatic conditions to infer global trends in abundance distributions.LocationGlobal.MethodsWe compiled data on tree species abundances and climate covariates from 605 sites worldwide. We applied linear regression modelling and nonlinear least squares fitting of log‐series and lognormal abundance distributions to species rank–order log‐abundance plots to assess latitudinal and climatic gradients in abundance distributions and Pielou evenness.ResultsWe observed significant latitudinal trends in SAD shape and evenness, even after accounting for richness and spatial effects. Evenness tended to increase towards lower latitudes and was positively correlated with actual evapotranspiration and negatively with climatic variability. We observed an excess of log‐series SADs at lower latitudes and an increase in lognormal distributions towards northern latitudes. Accordingly, the proportion of species less abundant than expected from a log‐series distribution decreased towards the tropics.ConclusionsWe speculate that the observed latitudinal trends are caused by respective gradients in the importance of dispersal for local tree community assembly. This interpretation implies the hypothesis that tropical communities tend to be more open and input‐driven in comparison to temperate communities.