Résumé
In a climate change context, soil ecosystem services can be threatened, notably through impacts on soil fauna. Collembola can be therefore used for bioindication of soil mesofauna functionality. Here we aim (i) to link distribution of the collembolan communities with their functional traits adaptations to climate conditions at a large scale, (ii) to evaluate how trait patterns are impacted by an experimental climatic treatment. The VULCAN project was carried out from 2001-2004 at 6 European shrublands sites located in Wales, Denmark, Netherlands, Hungary, Spain and Sardinia. Each site received warming and drought treatments in addition to an ambient control. Collembola were sampled from plants, soil surface, and soil, and the communities were characterised and compared in terms of taxonomic diversity and trait composition. Most up-to-date trait database version of the BETSI project (France) and SoilBioStore.au.dk (Denmark) were compiled. Observations on collembolan community structure tended to reflect long-term adaptations to climate. From North to South, biomass and density decreased while species richness tended to increase. Furthermore, analyses of collembolan trait adaptations are ongoing and traits patterns are expected to change along the climatic gradients. We know that in European collembolan communities, temperature play a major role in the variation of species traits, especially in open habitats. The present study aims to go further and qualify this role, and to quantify the effects of experimental warming and drought on traits shifts along climatic gradients. This work encourages further inquiries on collembolan responses from a functional biogeographic angle.