Science Source

Causes of warm-edge range limits: systematic review, proximate factors and implications for climate change

Synthesizes the known causes of species' warm-edge range limits, with emphasis on the underlying mechanisms (proximate causes)
Searches the literature for studies testing the causes of warm-edge range limits
Identifies 125 studies that address the causes of warm-edge limits, from a search including > 4000 studies
Finds that among the species in these studies, abiotic factors are supported more often than biotic factors in setting species range limits at warm edges, in contrast to the widely held view that biotic factors are more important
Finds in addition, only 23 studies (61 species) identified proximate causes of these limits, and these overwhelmingly support physiological tolerances to abiotic factors (primarily temperature)
Number of species (out of 178) for which various abiotic and biotic factors were examined (black bars) and supported (grey bars) as setting their warm-edge range limits, from a global set of studies examining ≤ 10 species. Note that a single species may have been examined for (and may support) more than one factor.