One-dimensional analyses of Rapoport's rule reviewed through meta-analysis

RUGGIERO, ADRIANA; WERENKRAUT, VICTORIA

GLOBAL ECOLOGY AND BIOGEOGRAPHY

Blackwell Publishing

Lugar: Oxford; Año: 2007 vol. 16 p. 401 - 414

0960-7447

ABSTRACTAimTo analyse quantitatively the extent to which several methodological,geographical and taxonomic variables affect the magnitude of the tendency for thelatitudinal ranges of species to increase with latitude (the Rapoport effect).LocationGlobal.MethodsA meta-analysis of 49 published studies was used to evaluate the effect ofseveral methodological and biological moderator variables on the magnitude of thepattern.ResultsThe method used to depict the latitudinal variation in range sizes is astrong moderator variable that accounts for differences in the magnitude of thepattern. In contrast, the extent of the study or the use of areal or linear estimations ofrange sizes does not affect the magnitude of the pattern. The effect of geography ismore consistent than the effect of taxonomy in accounting for differences in themagnitude of the pattern. The Rapoport effect is indeed strong in Eurasia and NorthAmerica. Weaker or non-significant latitudinal trends are found at the global scale,and in Australia, South America and the New World. There are no significantdifferences in the magnitude of the pattern between different habitats, however, theoverall pattern is weaker in oceans than in terrestrial regions of the world.Main conclusionsThe Rapoport effect is indeed strong in continental landmassesof the Northern Hemisphere. The magnitude of the effect is primarilyaffected by methodological and biogeographical factors. Ecological and spatial scaleeffects seem to be less important. We suggest that not all methodological approachesmay be equally useful for analysing the pattern.