Understanding global patterns in amphibian geographic range size: does Rapoport rule?

摘要: Aim  Species geographic ranges are the ‘fundamental units’ of macroecology. Range size is a major correlate extinction risk in many groups, and also critical studies biotic responses to climate change. Despite this, there lack exploring role environmental, historical anthropogenic processes determining large-scale patterns range size. We perform first global analysis putative drivers variation any group, choosing amphibians as our study taxon. Our aims disentangle hypothesized causes evaluate support for ‘Rapoport's rule’, observation that correlates with latitude. Location  Global. Methods  develop map gridded median using International Union Conservation Nature (IUCN) distribution maps. From this we spatial non-spatial regressions explore relationships between nine variables six biogeographic realms. use information-theoretic model selection compare multiple competing variables, simultaneously evaluating relative each one. Results  Current – environmental water energy, temperature seasonality consistently highly ranked analyses. Human impacts other measures (topographic landscape complexity, effective area, extremes) show mixed support, glacial history unimportant. findings add further evidence view Rapoport's rule regional, not global, phenomenon. Main conclusions  The primary importance may explain why largely restricted northern latitudes, where most pronounced. More generally, dominance contemporary analyses (even when accounting space) has stark implications future status amphibians. Changes will almost certainly interact already threatening third globally, effects being keenly felt by species range.