Restoration of degraded Chaco woodlands: Effects on reptile assemblages

We report changes in snake and lizard diversity and abundance following 25 years of Chaco forest restoration based on grazing suppression in Salta, Argentina. Reptile diversity and abundance was compared between a restored native forest (Los Colorados Biological Station, 10,000 ha) and an adjacent overgrazed area (Campo Grande, 7500 ha). The following parameters were measured: (a) habitat characteristics (cover of herb, shrub and tree strata) and (b) richness and abundance of lizards and snakes (captured with funnel traps). Herb and tree cover was higher in the restored area. General diversity of lizards and snakes (Shannon index) did not differ between sites. Eighteen snake species were captured (16 in the open area and 15 in the restored forest) and 14 lizard species (10 in the overgrazed and 12 in the restored forest). Relative abundance of some species differed between sites: Sibynomorphus lavillai, Stenocercus doellojuradoi were more abundant in the restored area, whereas Phimophis vittatus, Ameiva ameiva and Tropidurus etheridgei were more abundant in the overgrazed area. Our results suggest that habitat restoration in the Chaco must ensure availability of grasslands and other open areas that characterize the original landscape. Grazing suppression alone, however, may be insufficient to regenerate this kind of landscape.