Geographical patterns of phylogenetic beta‐diversity components in terrestrial mammals

Abstract

AbstractAimTo inve stigate geographical patterns of phylogenetic beta diversity (PBD) and its turnover and nestedness‐resultant components for terrestrial mammals. We expect an increase in the importance of the nestedness‐resultant component towards temperate regions given the historical loss of lineages caused by environmental and spatial constraints. Analogously, we expect to find a similar increase in the contribution of the nestedness‐resultant component towards higher elevations. We expect these patterns to be stronger for Rodentia because they have poor dispersal ability and may have been less efficient in recolonizing areas after glaciations.LocationWorld‐wide.MethodsWe generated the species composition of terrestrial Mammalia for 200 km × 200 km cells to calculate PBD and its turnover and nestedness‐resultant components. All measures were computed for each cell and the cells in the surrounding radius of one, two or three adjacent layers. We calculated the relative importance of the nestedness‐resultant component as the proportion of the total PBD (PBDratio) and also PBD deviation given taxonomic beta diversity (PBDdev). PBDdev measures the importance of phylogenetic beta diversity after factoring out taxonomic beta diversity. We used simple linear regressions and piecewise regressions to investigate relationships between PBDratio and mean annual temperature and elevation.ResultsWe found a major contribution of the nestedness‐resultant component linked to temperate climate, especially for groups with better dispersal capacity. Higher elevations were associated with a major contribution of the turnover‐resultant component, particularly for Rodentia.Main conclusionsWe provide the first global representation of PBD in terrestrial mammals and demonstrate that at higher latitudes PBD is mostly a result of lineage loss, whereas in highlands it is linked to lineage turnover. By analysing global patterns of the contribution of PBD components, we demonstrate that dispersal capacity is essential in determining the response of different lineages to geographical and environmental barriers.