Résumé
Main issue : is functional biodiversity as a key driver of organic matter degradation ?• Soil fauna represents a huge diversity of soil animals involved in a great number of soil ecosystem services (Lavelle et al. 2002, Kibblewhite et al., 2008)• In spite of their crucial issues, the relations between soil fauna biodiversity and soil behaviour are still poorly understood and very poorly predicted.• The use of functional groups and trait-based approaches improved the understanding of soil invertebrate diversity effect on soil functions compared to historiccaly taxonomic approaches.• Soil macrodetritiovres roles are pivotal in sofar as they are implied in organic matter degradation and participate to the regulation of biogeochemical cycles of elements such as carbon and nitrogen• Studies using a functional approach mainly concern litter decomposition in forest systems. Meadow systems are scarcely studied.• There are only scarce studies which dela with both functional diversity of litter and soil invertebrates.