Spatial and taxonomic correlates of species and species trait assemblages in soil invertebrate communities

Whether dispersal limitation and phylogenetic conservatism influence soil species assemblages is still a debated question. We hypothesized that spatial and phylogenetic patterns influence communities in a hump-backed fashion, maximizing their impact at intermediate spatial and phylogenetic distances. Species-environment relationships are blurred by dispersal limitation and restricted habitat choice at long and short spatial distances, respectively (Hypothesis 1). Co-occurrence of species/traits is limited by divergent evolution of species/traits and competitive exclusion at long and short phylogenetic distances, respectively (Hypothesis 2). Springtails were sampled over a wide array of environmental gradients, between-sample distance varying from a few cm to several km. We compared communities using species composition, habitat features, and geo-localization. We compared species using co-occurrence, habitat preference, traits and phylogeny. Mantel tests identified which factors contributed the best to species/traits assemblages. Within the studied area, species composition was influenced by habitat more than space. Traits displayed a strong phylogenetic signal, but they contributed less than habitat preferences to species co-occurrence. Species-environment relationships were better displayed within a 200m distance, supporting Hypothesis 1. Occurrence-habitat preference relationships were better displayed at family level, supporting Hypothesis 2. (C) 2013 Elsevier GmbH. All rights reserved.