Résumé

Investigating how trophic interactions influence the b-diversity of meta-communities is of paramount importance to understanding the processes shaping biodiversity distribution. Here, we apply a statistical method for inferring the strength of spatial dependencies between pairs of species groups. Using simulated community data generated from a multi-trophic model, we showed that this method can approximate biotic interactions in multi-trophic communities based on b-diversity patterns across groups. When applied to soil multi-trophic communities along an elevational gradient in the French Alps, we found that fungi make a major contribution to the structuring of b-diversity across trophic groups. We also demonstrated that there were strong spatial dependencies between groups known to interact specifically (e.g. plant-symbiotic fungi, bacteria-nematodes) and that the influence of environment was less important than previously reported in the literature. Our method paves the way for a better understanding and mapping of multi-trophic communities through space and time.

Référence : Ohlmann, M., Mazel, F., Chalmandrier, L., Bec, S., Chave, J., Coissac, E., Gielly, L., Pansu, J., Schilling, V., Taberlet, P., Zinger, L. & Thuiller, W. (2018) Mapping the imprint of biotic interactions on ?-diversity. Ecology Letters, 21, 1660-1669