Diversity of Small Mammals in the Pacific Coastal Desert of Peru and Chile and in the Adjacent Andean Area - Biogeography and Community Structure

Abstract

Species diversity patterns of small mammals (sigmodontine rodents) in the Chilean-Peruvian Pacific coastal desert and adjacent Andean area (Puna) were analysed by means of latitudinal and altitudinal transects. The statistical analyses of the patterns show: (1) a wide variation in latitudinal species diversity, with a peak in the region where the Puna reaches its greatest areal extent; (2) the differentiation of at least four groups of distinct faunal elements resulting from the interaction of large-scale biogeographic, geological and evolutionary processes; (3) a positive correlation between species richness and altitude for the altitudinal transects located within the Pacific coastal desert area and Puna; and (4) a highly individualistic pattern of community structure at a regional scale. These results are discussed considering biogeographic, palaeoclimatic and evolutionary processes, such as the establishment of the Pacific coastal desert, and the existence of a major centre of species diversification in the Puna area. Similarities and differences between these community-level patterns and those in North American deserts are discussed.