title: Exploring species and site contributions to beta diversity in stream insect assemblages.
abstract: It was recently suggested that beta diversity can be partitioned into contributions of single sites to overall beta diversity (LCBD) or into contributions of individual species to overall beta diversity (SCBD). We explored the relationships of LCBD and SCBD to site and species characteristics, respectively, in stream insect assemblages. We found that LCBD was mostly explained by variation in species richness, with a negative relationship being detected. SCBD was strongly related to various species characteristics, such as occupancy, abundance, niche position and niche breadth, but was only weakly related to biological traits of species. In particular, occupancy and its quadratic terms showed a very strong unimodal relationship with SCBD, suggesting that intermediate species in terms of site occupancy contribute most to beta diversity. Our findings of unravelling the contributions of sites or species to overall beta diversity are of high importance to community ecology, conservation and bioassessment using stream insect assemblages, and may bear some overall generalities to be found in other organism groups.
authors.affiliation: Finnish Environment Institute, Natural Environment Centre, Biodiversity, Paavo Havaksen Tie 3, 90570, Oulu, Finland. jani.heino@environment.fi.
authors.forename: Jani
authors.initials: J
authors.lastname: Heino
authors.affiliation: Department of Environmental Sciences, Section of Environmental Ecology, University of Helsinki, Niemenkatu 73, 15140, Lahti, Finland.
authors.forename: Mira
authors.initials: M
authors.lastname: Grönroos
mesh_terms: D000818:Animals; D044822:Biodiversity; D004463:Ecology; D017753:Ecosystem; D007313:Insecta; D045483:Rivers
keywords: Community ecology; Ecological uniqueness; Niche breadth; Occupancy; Species characteristics