Historical relationships of the Mexican cloud forests: A preliminary vicariance model applying Parsimony Analysis of Endemicity to vascular plant taxa

Abstract

Mexican cloud forests, situated between 600 and 3000 m of elevation, exhibit a remarkable high biotic diversity. They follow a freagmented pattern, similar to that of an archipelago, that makes them suitable to vicariance modelling. A Parsimony Analysis of Endemicity (PAE) was applied to the presence/absence of 1267 species of vascular plants (gymnosperms, angiosperms, and pteridophytes) freom twentyfour patches of Mexican cloud forests, in order to postulate a preliminary hypothesis of relationships. The single cladogram obtained grouped the twentyfour cloud forests into five clades. These results indicate that the Sierra Madre Oriental, Sierra Madre del Sur, and Serranias Meridionales floristic provinces do not represent natural units. A preliminary vicariance model is presented to explain the sequence of freagmentation of the Mexican cloud forests.