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

Abstract

Linear infrastructures such as roads are among the most frequent generators of anthropogenic disturbances. Due to the expensive area that is affected along them, these great 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 Nº 150 is an important road of South America that forms part of the Central Bioceanic Corridor which 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 between disturbed and undisturbed sites. In addition, 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. Twenty-one and 17 ant species were caught in disturbed and undisturbed sites, respectively. Roadside contained relatively more exclusives and rare species, while undisturbed sites harbored more common and dominant species. Hot climate specialists were more abundant at disturbed sites, whereas Opportunists at undisturbed sites. Ant species abundance seems to be positively in uenced by gravel cover on roadside. In the present context of land use change, roadside could have an important function as reservoir and corridor for some ant species, and thus, plays a valuable role in the conservation of ant diversity in arid ecosystems.