Relationships between Collembola, soil chemistry and humus types in forest stands (France)

Soil samples were taken under four tree species in various forest sites located in southern France. For each sampled A horizon of the soil profile, pH, organic matter content, C:N ratio and amounts of exchangeable cations (K, Ca, Mg) were measured, and collembolan fauna was extracted using Berlese-Tullgren funnels. A total of 78 species representing 11 families and 47 genera were identified. The relationships between Collembola and soil parameters were determined by co-inertia analysis which corresponds to the simultaneous Correspondence Analysis of the collembolan data table and the Multiple Correspondence Analysis of the environmental data table. The analysis revealed that the distribution of 10 species was related to pH, organic matter content via C and N and to base cations (K, Ca, Mg). Samples, linking these collembolan species and chemical parameters, were clustered according to humus forms. Collembola seem to be linked closer to the physical structure of humus than to its chemical parameters. Their specific contribution to pedogenetic processes as yet remains to be clarified.