Effect of road disturbance on ant diversity in the Monte desert of Argentina

Abstract

Roads are among the most frequent generators of anthropogenic disturbances. Due to the extensive area that is affected along them, these infrastructures represent a major conservation concern worldwide. Ants are an important component of natural ecosystems and are considered to be very sensitive to disturbance. The National Road 150 forms part of the Central Bioceanic Corridor that will connect Brazil with Chile. In its trajectory, it crosses the Ischigualasto Provincial Park in Argentina. In order to evaluate the effects of this road on biodiversity in roadsides that run across this protected area, we compared species and functional group diversity of ants collected using pitfall traps at disturbed and undisturbed sites. Also, we analyzed whether habitat variables, such as plant cover, gravel cover and soil hardness, explain ant species and functional group abundance in both site types. Nineteen and 16 species were captured at disturbed and undisturbed sites respectively, with roadside containing relatively more exclusives and rare species. Hot climate specialists were the most abundant at both sites, whereas Army ants were exclusive at disturbed sites. Ant abundance was positively associated with gravel cover on the roadside. Results suggest that with the current management, there were no profound changes in the ant community due to the road edge effects. In the present context of land use change, roadside could function as reservoir and corridor for some ant species, contributing to the conservation of ant diversity in this arid ecosystem.