Haegeman Bart, Loreau Michel
Centre for Biodiversity Theory and Modelling, Station d'Ecologie Expérimentale du Centre National de la Recherche Scientifique (CNRS), 2 Route du CNRS, 09200 Moulis, France.
Am Nat. 2015 Jan;185(1):E1-13. doi: 10.1086/679066. Epub 2014 Dec 2.
Ecological communities are structured by processes operating at multiple spatial scales, which results in an often daunting complexity. Here we present a simple graphical theory to study the interaction of two fundamental community processes: resource competition at the local scale and dispersal at the regional scale. We consider a metacommunity model with two habitat patches in which consumer species compete for a spatially distributed resource. We introduce a graphical construction of the equilibrium metacommunity composition, analogous to traditional competition theory for two resources. As in the nonspatial case, the zero net growth isoclines (ZNGIs) play a central role in the analysis. We show that a consumer species' ZNGI depends on its dispersal characteristics, and this dependence leads to a unification of various dispersal-based coexistence mechanisms. We illustrate this unification using four specific mechanisms: species-specific dispersal rates, spatially asymmetric dispersal, resource-dependent dispersal, and competition between habitat specialists and generalists.
生态群落是由在多个空间尺度上运行的过程构建而成的，这往往导致令人望而生畏的复杂性。在此，我们提出一种简单的图形理论，以研究两个基本群落过程的相互作用：局部尺度上的资源竞争和区域尺度上的扩散。我们考虑一个具有两个栖息地斑块的集合群落模型，其中消费者物种竞争一种空间分布的资源。我们引入一种平衡集合群落组成的图形构建方法，类似于两种资源的传统竞争理论。与非空间情况一样，零净增长等斜线（ZNGIs）在分析中起着核心作用。我们表明，消费者物种的ZNGI取决于其扩散特征，这种依赖性导致了各种基于扩散的共存机制的统一。我们使用四种具体机制来说明这种统一：物种特异性扩散率、空间不对称扩散、资源依赖性扩散以及栖息地专家物种和通才物种之间的竞争。
