Ant and tenebrionid beetle assemblages in arid lands: Their associations with vegetation types in the Patagonian steppe

- Describes the little known arthropod fauna in the South-eastern Patagonian steppe.
- Shows ground-dwelling arthropod perceive vegetation types as different in suitability.
- Shows the importance of considering vegetation heterogeneity in arid environments.
- Provides valuable information for conservation priorities in arid environments.

Arid environments have long been perceived as simple and homogeneous ecosystems, but slight differences in precipitation, topography and soil attributes result in a variety of distinct plant associations. The availability of different vegetation types leads to a non-uniform distribution of resources and abiotic conditions, which may affect the spatial distribution of their associated fauna. Here we describe a study, in the San Jorge Gulf district of Patagonia, where we tested the relationships between ant and tenebrionid diversity and composition and discrete vegetation types in an area where invertebrate fauna is poorly known. We captured 5019 individuals, from 13 to 21 species, of ants and tenebrionids, respectively. We found differences in composition of ants and tenebrionids among the vegetation types, with unique ant composition on peladales and subshrub steppes, and distinct tenebrionid assemblages in all vegetation types. Our results show that ants and darkling beetles responded differently to vegetation type. Because both taxa are key components of arid environment fauna, it is important to consider vegetation heterogeneity when developing management plans to conserve biological diversity and ecological functions in these environments.