Within the framework of VISTA project (Vulnerability of Ecosystem Services to Land Use Change in Traditional Agricultural Landscapes), we have studied impacts of land use change on the grasslands of Villar d’Arène (France, 05) and on their services. For that purpose, we used an approach based on plant functional traits (Specific leaf area, leaf dry matter content, leaf nitrogen content, toughness, vegetative height). Those traits are correlated with plant strategy in its environment. We were able to connect the environment and traits and traits and ecosystem processes, which allowed us to connect, indirectly, the environment, so agricultural practices, and ecosystem processes. Mown meadows, because of the selection of species with fast turnover of mineral nutrients, are more productive and a better litter decomposition rate than grazed meadows. We have also connected agricultural practice and services’ descriptors. Thus, grazed meadows have more grasses contributing to their biomass than the mown one and they also have less diversity than those mown meadows. Nevertheless, we did not notice a real incompatibility between meadows’ services. Thus, mown meadows have to be maintained as well for their good agronomical value as for the other services like aesthetical value, ecological or educational values. We want to insist on the fact that those conclusions are the result of the management practices of the studied area.