The main objective of the present project consists of analyzing experimentally the impact of two sources of stress (climate and land-use changes) on functioning of mediterranean savannah-like ecosystems (dehesa systems) via changes in the functional structure and diversity of plant and soil microorganism communities. For this purpose, we will set up a manipulative experiment of rainfall exclusion and increased temperature in three dehesa systems facing a different grazing intensity. We will use a trait-based, multidisciplinary and multi-trophic approach, quantifying relevant functional attributes not only in dominant plants but also in the soil biota that interacts with them for the provision of key ecosystem services related with net primary productivity and the biogeochemical cycles of carbon, nitrogen and phosphorous. In addition, we will evaluate the potential role of isolated trees to mitigate the impact caused by the on-going aridity conditions. We hypothesize that the increasing aridity will exercise a strong impact on the functional structure and diversity of plant and microbial communities, with important repercussions for ecosystem processes and services. In general, it would be expected that the most important changes occur in those dehesas facing to a higher grazing intensity, likely as a consequence of the strong filter of both stress sources.The findings provided by this project will be contribute to better understand the ecological consequences of global change drivers on ecosystem potential to deliver relevant services as well as to implement successful management and conservation plans in future environmental scenarios.