Soil animals are important in the conversion of biomass into organic matter in the soil, which is strongly affects the the balance and fate of organic C in the soil. Despite fact that overall direct contribution of soil invertebrates to C turnover is usually assumed to be small soil fauna can substantially enhance or slow down microbial decomposition of organic matter and thus C turnover. This session aims at the studies that quantify the role of (soil) animals on Carbon dynamics in the soil, and their possible impact on climate change by the production of CO2 and CH4.