title: Inferring species roles in metacommunity structure from species co-occurrence networks.
abstract: A long-standing question in community ecology is what determines the identity of species that coexist across local communities or metacommunity assembly. To shed light upon this question, we used a network approach to analyse the drivers of species co-occurrence patterns. In particular, we focus on the potential roles of body size and trophic status as determinants of metacommunity cohesion because of their link to resource use and dispersal ability. Small-sized individuals at low-trophic levels, and with limited dispersal potential, are expected to form highly linked subgroups, whereas large-size individuals at higher trophic positions, and with good dispersal potential, will foster the spatial coupling of subgroups and the cohesion of the whole metacommunity. By using modularity analysis, we identified six modules of species with similar responses to ecological conditions and high co-occurrence across local communities. Most species either co-occur with species from a single module or are connectors of the whole network. Among the latter are carnivorous species of intermediate body size, which by virtue of their high incidence provide connectivity to otherwise isolated communities playing the role of spatial couplers. Our study also demonstrates that the incorporation of network tools to the analysis of metacommunity ecology can help unveil the mechanisms underlying patterns and processes in metacommunity assembly.
authors.affiliation: Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago CP 6513677, Chile Instituto de Ecología y Biodiversidad (IEB), Casilla 653, Santiago, Chile Centro Universitario Regional Este (CURE), Universidad de la República Uruguay, Maldonado, Uruguay borthagaray@gmail.com.
authors.forename: Ana I
authors.initials: AI
authors.lastname: Borthagaray
authors.affiliation: Centro Universitario Regional Este (CURE), Universidad de la República Uruguay, Maldonado, Uruguay Departamento de Ecología y Evolución, Facultad de Ciencias, Iguá 4225 Piso 9 Sur, Montevideo, Uruguay.
authors.forename: Matías
authors.initials: M
authors.lastname: Arim
authors.affiliation: Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago CP 6513677, Chile Instituto de Ecología y Biodiversidad (IEB), Casilla 653, Santiago, Chile Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA Laboratorio Internacional en Cambio Global (LINCGlobal), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Pablo A
authors.initials: PA
authors.lastname: Marquet
mesh_terms: D000818:Animals; D001181:Arthropods / Q000502:physiology*; D049628:Body Size; D060435:Carnivory; D002677:Chile; D003889:Desert Climate; D017753:Ecosystem; D060434:Herbivory; D008116:Lizards / Q000502:physiology*; D016015:Logistic Models; D011157:Population Dynamics
keywords: body size; co-occurrence network; metacommunity structure; modularity analysis; trophic position