Aggregation And Spatial Coexistence of Earthworm Community in Grassy Savanna of Lamto (Côte d’Ivoire)

Abstract

Understanding of mechanisms by which species spatially coexist, come from the theoretical framework and has focussed on spatial competition. Earthworms were sampled in rainy season on a grid obtained from grassy savanna to explore spatial competition. We used geostatistical analysis to assess spatial dependence within community between different population patterns. Empirical results revealed among earthworm community two groups of species appeared of interest in term of association. The Eudrilidae species (Stuhlmannia porifera, Chuniodrilus zielae, and Chuniodrilus sp1) on the one part were negatively associated with Millsonia omodeoi (Megascolecidae) on the other part, whereas we observed significant positive association between C.zielae and S.porifera. This study indicates that the competitive interaction structures the community and this competition is detected through reduced density of one competitor when they spatially collocated.