COSAR

Many river restoration projects, recreating local hydromorphological structures and habitats, have been implemented worldwide aiming at improving the ecological status of rivers. However, ecological outcomes (e.g. improved community structure and functions, reinforcement of ecosystem processes) strongly depend on multiple drivers and processes at various spatial scales, submitted to multiple human stressors, also potentially affected by past conditions legacies. The landscape “context” is crucial in restoration planning but the quantitative effects of the various context variables in restoration practice, as well as the role of metacommunities, the scale issue and the role of legacy effects are still understudied and thus poorly considered. Furthermore, knowledge also lacks on societal needs and benefits from restoration, as most operations focus on the ecological quality criteria. The achievement of societal goals is rarely reviewed and factors of success are not yet systematically examined, although this is crucial for a complete and sustainable success of restoration project. In this context, COSAR is designed to identify the combined effects of context variables on both ecological and societal outcomes of river physical restoration projects, and which combinations favour synergies or antagonisms between both outcomes types.