Extensive vs. semi-intensive grazing systems – are ants sensitive to this difference?

Abstract

Our aim was to evaluate environmental changes caused by Voisin grazing system, using ants as bioindicators. Our hypothesis was that species richness and composition are influenced by the impact. We sampled ants in an extensive grazing system, semi-intensive Voisin and a forest fragment using 16 pitfall traps in each area, on the Barro Preto Farm, Carrancas, Minas Gerais. Ant species richness was negatively influenced by the environmental impact, since both grazing systems had the same species richness, and we found a higher species richness in the forest fragment. Species composition follows the same pattern, as the composition between grazing systems was similar but different from the forest fragment. We suggest there was not enough time for the grazing systems to become different from each other in terms of impact, but the agriculture intensification negatively affect terrestrial invertebrate fauna.