The BIOGEI project aims at disentangling the relationship between biodiversity and biogeochemical services in pastures, including greenhouse gas mitigation and carbon storage. We hypothesize that those interactions depend on climatic conditions, land uses and management options; that is, differences in socio-ecological systems will determine differences in climate change vulnerability and mitigation potential, providing alternative options for mitigation and adaptation. Of particular interest are the links between the carbon and nutrient cycles in mountain pastures and how those respond to global change factors. We evaluate the possible effects of climate change, land use and management by studying pastures along altitudinal and latitudinal gradients. Mechanisms linking biodiversity and biotic interactions with greenhouse gas emissions and carbon storage in pastures are assessed through infrastructures to continuously measure CO2 fluxes in eddy-covariance micrometeorological towers and photoacoustic instrumentation to calculate CO2 , CH4 and N2O fluxes in field campaigns among other techniques. Special attention is paid to extending generalized biodiversity-interactions (GDI) modeling from experimental set-ups to semi-natural grasslands. Strong interaction with stakeholders is expected to clarify the role of socio-ecological systems on climate change mitigation and adaptation options, and guarantee the dissemination of BIOGEI results to farmers, managers and policy-makers.