Still little evidence of poleward range shifts in the tropics, but lowland biotic attrition may be underway

Abstract

Sixteen years ago, Colwell et al. (2008: Global warming, elevational range shifts, and lowland biotic attrition in the wet tropics. Science, 322, 258) affirmed predictions that climate change and rising global temperatures would lead to widespread upslope range shifts of tropical species but predicted that poleward range shifts would be unlikely within the terrestrial wet tropics, because of the shallow latitudinal temperature gradient. They also predicted “biotic attrition” (a net loss of species) in equatorial lowlands, where no warmer regions exist as a source of more‐thermophilic species to replace species shifting upslope. Based on three recently published literature reviews of range shifts, covering more than 450 studies and thousands of species worldwide, we document more than 20 cases of elevational range shifts within the tropics, but we find no unambiguous examples of a latitudinal range shift for any fully tropical terrestrial species. In contrast, outside the tropics, the majority of documented range shifts are latitudinal. We summarize the state of knowledge about climate‐driven species range shifts in the terrestrial tropics and highlight the potential for climate change to cause extensive and widespread declines in lowland alpha diversity. in Spanish is available with online material.