title: Hierarchical spatial segregation of two Mediterranean vole species: the role of patch-network structure and matrix composition.
abstract: According to ecological theory, the coexistence of competitors in patchy environments may be facilitated by hierarchical spatial segregation along axes of environmental variation, but empirical evidence is limited. Cabrera and water voles show a metapopulation-like structure in Mediterranean farmland, where they are known to segregate along space, habitat, and time axes within habitat patches. Here, we assess whether segregation also occurs among and within landscapes, and how this is influenced by patch-network and matrix composition. We surveyed 75 landscapes, each covering 78 ha, where we mapped all habitat patches potentially suitable for Cabrera and water voles, and the area effectively occupied by each species (extent of occupancy). The relatively large water vole tended to be the sole occupant of landscapes with high habitat amount but relatively low patch density (i.e., with a few large patches), and with a predominantly agricultural matrix, whereas landscapes with high patch density (i.e., many small patches) and low agricultural cover, tended to be occupied exclusively by the small Cabrera vole. The two species tended to co-occur in landscapes with intermediate patch-network and matrix characteristics, though their extents of occurrence were negatively correlated after controlling for environmental effects. In combination with our previous studies on the Cabrera-water vole system, these findings illustrated empirically the occurrence of hierarchical spatial segregation, ranging from within-patches to among-landscapes. Overall, our study suggests that recognizing the hierarchical nature of spatial segregation patterns and their major environmental drivers should enhance our understanding of species coexistence in patchy environments.
authors.affiliation: Unidade de Biologia da Conservação, CIBIO/InBio-Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade de Évora, Pólo de Évora, Núcleo da Mitra, Apartado 94, 7002-554, Évora, Portugal. ricardo.pita@gmail.com.|CEABN/InBIO, Centro de Ecologia Aplicada "Professor Baeta Neves", Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017, Lisboa, Portugal. ricardo.pita@gmail.com.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pita
authors.affiliation: School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK.
authors.forename: Xavier
authors.initials: X
authors.lastname: Lambin
authors.affiliation: Unidade de Biologia da Conservação, CIBIO/InBio-Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade de Évora, Pólo de Évora, Núcleo da Mitra, Apartado 94, 7002-554, Évora, Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Mira
authors.affiliation: CEABN/InBIO, Centro de Ecologia Aplicada "Professor Baeta Neves", Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017, Lisboa, Portugal.|EDP Biodiversity Chair, CIBIOI/InBIO-Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, Porto, 4485-661, Vairão, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Beja
mesh_terms: D000383:Agriculture; D000818:Animals; D003411:Arvicolinae; D002980:Climate; D017753:Ecosystem; D004777:Environment
keywords: Cabrera vole; Competition; Landscape heterogeneity; Patchy environments; Southern water vole; Species coexistence