Biogeography, ecology, and spatial patterns of patagonian lizards

Abstract

Patagonia has a great diversity of lizards, including 6 families, 11 genera and 163 species. The majority of this diversity with documented geographical records corresponds to the Liolaemidae family (Phymaturus and Liolaemus). Latitudinally, lizard richness is higher between 37° to 39° S, decreasing gradually until latitude 54° S; longitudinally, it is higher between 69° and 71° W. The georeferenced records and the number of collected specimens have some biases, with higher values in the northern regions (up to latitude 42° S). However, there are areas up to latitude 45° S with species richness similar to others with a greater number of collected individuals. The vegetation units with the highest species richness (S) in Argentinean Patagonia are the northern and central areas reaching west of Chubut Province: Western District (S = 60) and Typical Southern Monte (S = 49), passing through areas with intermediate richness and with only one species (Wet Magellanic Steppe) or none (Evergreen shrub, Monte?s Mountains and Valleys, Western Interior Pampa, and Peat Bogs). There is a general trend towards lower species richness in vegetation units located in the extreme south of Argentina and south of latitude 41° S in Chile. We evaluated differences in lizard diversity and evenness among vegetation units through a dendrogram based on species incidences and found 6 clusters. Then, we compared species richness between members of each cluster with rarefaction curves. Species marginally distributed in Patagonia have a narrower altitudinal range than Patagonian endemics. Species in genus Liolaemus have small differences in altitudinal range, but species of Phymaturus have pronounced differences in altitudinal ranges. Our spatial analyses, based on intensive systematic-taxonomic activity over the last two decades, shed light into the understanding of lizard distributions in one of the regions with the greatest diversity of reptiles in the world. We also provide ecological and spatial metrics for an updated list of Patagonian lizards. We highlight that the usefulness of discretizing large volumes of information and geographic space into a synthetic framework allows using quantitative results for the study of spatial patterns of biodiversity, decision-making for design studies, use of resources and creation of protected areas.