title: Environmental filtering determines metacommunity structure in wetland microcrustaceans.
abstract: Metacommunity approaches are becoming popular when analyzing factors driving species distribution at the regional scale. However, until the popularization of the variation partitioning technique it was difficult to assess the main drivers of the observed patterns (spatial or environmental). Here we propose a new framework linking the emergence of different metacommunity structures (e.g., nested, Gleasonian, Clementsian) to spatial and environmental filters. This is a novel approach that provides a more profound analysis of how both drivers could lead to similar metacommunity structures. We tested this framework on 110 sites covering a strong environmental gradient (i.e., microcrustacean assemblages organized along a salinity gradient, from freshwater to brackish water wetlands). First we identified the metacommunity structure that better fitted these microcrustacean assemblages. Then, we used hierarchical variation partitioning to quantify the relative influences of environmental filters and the distance among wetlands on the identified structure. Our results showed that under strong environmental filtering metacommunity structures were non-random. We also noted that even passive dispersers, that are supposed to be poorly spatially filtered, showed spatial signals at a large geographical scale. However, some difficulties arose when inferring biotic interactions at finer-scale spatial signals. Overall, our study shows the potential of elements of metacommunity structure combined with variation partition techniques to detect environmental drivers and broadscale patterns of metacommunity structure, and that some caution is needed when interpreting finer-scale spatial signals.
authors.affiliation: GRECO, Institute of Aquatic Ecology, University of Girona, Girona, Spain. stephanie.gascon@udg.edu.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Gascón
authors.affiliation: GRECO, Institute of Aquatic Ecology, University of Girona, Girona, Spain.|BETA Research Group, University of Vic-Central University of Catalonia, Catalonia, Spain.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Arranz
authors.affiliation: BETA Research Group, University of Vic-Central University of Catalonia, Catalonia, Spain.|FEM (Freshwater Ecology and Management) Research Group, University of Barcelona, Barcelona, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Cañedo-Argüelles
authors.affiliation: IRTA Aquatic Ecosystems, Sant Carles de la Ràpita, Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Nebra
authors.affiliation: GRECO, Institute of Aquatic Ecology, University of Girona, Girona, Spain.|Global Institute of Sustainability, Arizona State University, Tempe, USA.
authors.forename: Albert
authors.initials: A
authors.lastname: Ruhí
authors.affiliation: FEM (Freshwater Ecology and Management) Research Group, University of Barcelona, Barcelona, Spain.|IRBio (Institut de Recerca de Biodiversitat), University of Barcelona, Barcelona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Rieradevall
authors.affiliation: IRTA Aquatic Ecosystems, Sant Carles de la Ràpita, Spain.
authors.forename: Nuno
authors.initials: N
authors.lastname: Caiola
authors.affiliation: GRECO, Institute of Aquatic Ecology, University of Girona, Girona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Sala
authors.affiliation: IRTA Aquatic Ecosystems, Sant Carles de la Ràpita, Spain.
authors.forename: Carles
authors.initials: C
authors.lastname: Ibàñez
authors.affiliation: GRECO, Institute of Aquatic Ecology, University of Girona, Girona, Spain.
authors.forename: Xavier D
authors.initials: XD
authors.lastname: Quintana
authors.affiliation: GRECO, Institute of Aquatic Ecology, University of Girona, Girona, Spain.
authors.forename: Dani
authors.initials: D
authors.lastname: Boix
mesh_terms: D000818:Animals; D058448:Biota; D003445:Crustacea / Q000145:classification / Q000502:physiology*; D013030:Spain; D053833:Wetlands
keywords: Cladocera; Copepoda; Moran eigenvector maps; Ostracoda; Salinity