Laroche Fabien, Jarne Philippe, Perrot Thomas, Massol Francois
CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul Valéry Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier Cedex 5, France AgroParisTech ENGREF, 19 avenue du Maine, 75732 Paris Cedex 15, France Irstea, UR EFNO, Domaine des Barres, 45290 Nogent-sur-Vernisson, France Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 75007 Uppsala, Sweden
CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul Valéry Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier Cedex 5, France.
Proc Biol Sci. 2016 Apr 27;283(1829). doi: 10.1098/rspb.2016.0548.
Difference in dispersal ability is a key driver of species coexistence in metacommunities. However, the available frameworks for interpreting species diversity patterns in natura often overlook trade-offs and evolutionary constraints associated with dispersal. Here, we build a metacommunity model accounting for dispersal evolution and a competition-dispersal trade-off. Depending on the distribution of carrying capacities among communities, species dispersal values are distributed either around a single strategy (evolutionarily stable strategy, ESS), or around distinct strategies (evolutionary branching, EB). We show that limited dispersal generates spatial aggregation of dispersal traits in ESS and EB scenarios, and that the competition-dispersal trade-off strengthens the pattern in the EB scenario. Importantly, individuals in larger (respectively (resp.) smaller) communities tend to harbour lower (resp. higher) dispersal, especially under the EB scenario. We explore how dispersal evolution affects species diversity patterns by comparing those from our model to the predictions of a neutral metacommunity model. The most marked difference is detected under EB, with distinctive values of both α- and β-diversity (e.g. the dissimilarity in species composition between small and large communities was significantly larger than neutral predictions). We conclude that, from an empirical perspective, jointly assessing community carrying capacity with species dispersal strategies should improve our understanding of diversity patterns in metacommunities.
扩散能力的差异是集合群落中物种共存的关键驱动因素。然而,现有的用于解释自然中物种多样性模式的框架往往忽视了与扩散相关的权衡和进化限制。在此,我们构建了一个考虑扩散进化和竞争 - 扩散权衡的集合群落模型。根据群落间承载能力的分布情况,物种的扩散值要么围绕单一策略(进化稳定策略,ESS)分布,要么围绕不同策略(进化分支,EB)分布。我们表明,有限扩散在ESS和EB情景下会产生扩散性状的空间聚集,并且竞争 - 扩散权衡会在EB情景中强化这种模式。重要的是,较大(分别对应较小)群落中的个体往往具有较低(对应较高)的扩散能力,尤其是在EB情景下。我们通过将模型结果与中性集合群落模型的预测结果相比较,探索扩散进化如何影响物种多样性模式。在EB情景下检测到最显著的差异,α - 多样性和β - 多样性都有独特的值(例如,小群落和大群落之间物种组成的差异明显大于中性预测)。我们得出结论,从实证角度来看,联合评估群落承载能力和物种扩散策略应能增进我们对集合群落中多样性模式的理解。