International audienceUnderstanding the benefits humans receive from ecosystems is a high priority in socio-ecological research. Several frameworks describing the delivery of ecosystem services (ES) have been proposed, and recently, an increasing attention is being given to the social component (i.e. the beneficiaries) of ES. Stakeholders do not access ES equally and consequently do not benefit the same way from ecosystems. Inequalities are explained by spatial characteristics (i.e. upstream and downstream beneficiaries of a watershed), interactions among ES (i.e. tradeoffs between the provision of multiple ES) and among stakeholders (i.e. tradeoffs between beneficiaries). Power relationships have an important role in ES tradeoffs. While th...