Chorotypes and geographic relationships among endemic species of the Transmexican Volcanic Belt, Mexico

Abstract

The Transmexican Volcanic Belt (TVB) is a complex biogeographical province characterized by several areas of endemism and high diversity of flora and fauna produced by complex geological and evolutionary processes. Chorotypes are biogeographical patterns that occur either when 2 or more independently distributed species share the same occupied area, or even when a single species’ distribution area differs significantly from others. Here, we identified chorotypes of 167 endemic species inhabiting the TVB using geographic distribution models and quantitative methods. Of those species, 136 were included in 11 chorotypes, named I to XI. In addition, the insect Aedes niveoscotum constituted chorotype XII. The 30 remaining species did not belong to any chorotype. All chorotypes included species from different taxonomic groups, which may be due to a shared biogeographical history. The chorotypes with the highest richness were located in the central and eastern TVB, suggesting that volcano peaks and surrounding areas are important for generating the particular environmental conditions that restrict the distribution of species of different taxonomic groups.