Rapoport's rule, species tolerances, and the latitudinal diversity gradient: geometric considerations

Abstract

The most pervasive species-richness pattern, the latitudinal gradient of diversity, has been related to Rapoport's rule, i.e., decreasing latitudinal extent of species' ranges toward the equator.We show, using a simple geometric model, that the postulated decrease of species' potential range sizes toward the tropics would itself lead to a latitudinal gradient opposite to that observed.

Keywords

• biodiversity
• biogeography
• equatorial effect
• implicit latitudinal gradient
• macroecology