Biogeographic units in the Chihuahuan Desert: implications for regionalization and area nomenclature

There are several biogeographic regionalizations of the Chihuahuan Desert province, which differ in the criteria used, and the names and categories given to the different biotic units recognized. We compared maps of these biogeographic regionalizations, detecting similarities and differences in the units recognized, and searched for endemic plant and animal taxa diagnosing them. Eight biotic units are recognized and named: Chihuahuan Desert province, Chihuahuan subprovince (including the Trans-Pecos and Mapimian districts), and Mexican Plateau subprovince (including the Saladan, Mexican Southern Arid and Tehuacan-Cuicatlan Valley districts). These subprovinces and districts are hypothesized to represent natural biotic units, each harboring a particular assemblage of endemic taxa.