Ants (Hymenoptera: Formicidae) as surrogates for epigeic arthropods in Northern Andalusian ‘dehesas’ (Spain)

Abstract

The ‘dehesas’ are important and vast agro-silvo-pastoral systems typical of the Iberian Peninsula that are undergoing a crisis due to their low economic profitability and environmental degradation. Thus, it is necessary to identify effective tools that provide a reliable idea of the status of these ecosystems as a starting point for future measures of conservation. In this study we analyse the possible role of ants as surrogates for epigeic arthropods, a common biodiversity indicator group. A total of 15 farms were sampled throughout Sierra Morena (Andalusia, Spain) with pitfall traps, both for the ‘dehesa’ habitats themselves and for different microhabitats within the study sites. First, we achieve a complete list of the species of ants of the area. The results indicate that the ‘dehesa’ habitats were very homogenous for all farms, while microhabitats showed differences in species richness and ant communities’ composition compared to the ‘dehesas’. To evaluate the role of ants as surrogates, the number of traps occupied by each order of arthropod and by each ant species was compared. We found a high correlation between them what confirm the surrogate character of ants for the rest of arthropods in these ecosystems.

Keywords

• bioindicators
• formicidae
• pastureland
• holm oak
• pitfall traps