Exploring the effect of soil management intensity on taxonomic and functional diversity of ants in Mediterranean olive groves

Agricultural intensification is one of the major drivers behind biodiversity loss in Mediterranean agroecosystems. The intensification of olive groves as monoculture in large areas of the southern Spain has had important effects on biodiversity and ecological processes. In the present study, we explore the olive grove soil management practices effects on taxonomic and functional diversity of ants along a gradient of soil management intensity. We predict that both species richness and functional diversity decrease with an increasing intensification of olive grove soil management. We used pitfall traps to sample ants in 24 olive groves subject to different soil management regimes in southern Spain, and then compared ant species richness and functional diversity (FD). Nonploughed organic farms showed higher species richness. Ploughing was observed to be the soil management practice with the greatest negative effect on ant species richness. Three functional traits significantly responded to soil management intensity, with tibia length and head width showing a higher FD in organic farms and diet showing a lower FD in ploughed farms. The results of the present study highlight the negative effects of olive grove ploughing on ant biodiversity and provide novel evidence of the nonploughing organic farming role with respect to maintaining higher levels of ant functional diversity.