title: A graphical-mechanistic approach to spatial resource competition.
abstract: 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.
authors.affiliation: 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.
authors.forename: Bart
authors.initials: B
authors.lastname: Haegeman
authors.forename: Michel
authors.initials: M
authors.lastname: Loreau
mesh_terms: D063147:Animal Distribution; D000818:Animals; D058448:Biota; D003163:Competitive Behavior; D017753:Ecosystem; D008962:Models, Theoretical; D011157:Population Dynamics; D013045:Species Specificity