Abstract
Aim This study assesses the extent to which biogeographic patterns in freshwaterfish beta diversity and nestedness are due to dispersal limitation, from differencesin dispersal opportunity across geographic areas and in dispersalability across species.Location Europe and the Atlantic and Pacific realms of North America (NA),east and west of the Continental Divide.Methods The effects of glaciation, realm shape, connectivity, current climateand vagility on regional-level beta diversity and nestedness were investigated.Turnover and nestedness-resultant dissimilarity components of beta diversityand the nestedness metric based on overlap and decreasing fill (NODF) werecalculated from regional species lists and the contributions of turnover andsegregation to nestedness structure quantified.Results Geographic distance was a stronger predictor of beta diversity thanclimatic and environmental heterogeneity distances. Species range shapes variedwith postglacial colonization direction, being more extensive in an east–westdirection in Europe than in Atlantic NA. Turnover increased with decliningconnectivity, in unglaciated areas, and in non-migratory species. Species weresignificantly less nested than expected because of high turnover and withinrealmheterogeneity in regional faunas. Deviations from nestedness were greaterin unglaciated areas and in migratory species. Non-migrants, but not migrants,exhibited coincident range boundaries.Main conclusions Spatial trends in beta diversity and nestedness in freshwaterfish in NA and Europe result primarily from differences in postglacial recolonizationopportunity across realms and in dispersal ability across species.Multiple metrics are necessary to identify the processes determining the spatialstructure of species assemblages.
Original language | English |
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Pages (from-to) | 1723-1733 |
Journal | Journal of Biogeography |
Volume | 44 |
DOIs | |
Publication status | Published (in print/issue) - 1 Aug 2017 |
Keywords
- anti-nestedness
- beta diversity
- dispersal limitation
- freshwater fish
- glaciation
- idiosyncrasy
- latitudinal gradients
- nestedness-resultant dissimilarity
- species segregation
- turnover