Effects of soil macrofauna and of drought on the decomposition of dead leaves of mediterranean shrubs

A microcosm experiment was set up to study the impact of a decrease in rainfall on soil fauna activity and its consequences for litter decomposition. Litter consumption by the diplopod Ommatoiulus sabulosus as well as its effect on microbial decomposers was studied under two different moisture levels. Our main finding was that the decrease in water availability did not affect litter consumption by Ommatoiulus sabulosus. This result suggests that soil fauna are more resistant to drought than microbial decomposers. Soil fauna could therefore be important for sustaining decomposition processes in Mediterranean ecosystems where it is predicted that droughts will be more severe and more frequent. Mathieu COULIS CENTRE D’ECOLOGIE FONCTIONNELLE ET EVOLUTIVE UMR 5175 CNRS 1919 route de Mende F-34293 MONTPELLIER CEDEX 5 (mcoulis@gmail.com)