Résumé
Identifying the environmental parameters governing patterns of biodiversity and community composition is particularly important for planning conservation schemes and predicting response of communities to global change. To highlight the parameters most relevant for explaining patterns in ant assemblages at a local scale, we described ant communities in 95 plots distributed along environmental gradients on a mountain in the Mediterranean region of southern France. Among the six environmental parameters considered (slope, exposition, elevation, tree basal area, tree species diversity, and the dominant tree species), tree basal area (a good proxy for tree cover) and elevation had by far the strongest influence on ant species richness, diversity, and community composition. Ant richness and diversity decreased with increasing tree cover and elevation. Tree cover had a stronger effect than elevation, corroborating the longstanding hypothesis that radiant energy that heats foraging substrates might be more relevant to ants than average temperature. Deciphering local processes that structure communities contributes to a better understanding of global patterns.