The Cassaïre wetland restoration project: defining the reference ecosystem

Résumé En

Defining a reference ecosystem for ecological restoration project is an essential step. The reference can correspond to the historical ecosystem, can be defined to solve environmental issues or can correspond to a socioecosystem. For the restoration of the Cassaïre site in the Camargue delta in southern France, the reference ecosystems chosen are : Mediterranean temporary wetlands and Mediterranean meso-xeric grasslands. The choice of these two reference ecosystems appears logical considering their contribution to regional biodiversity. Temporary wetlands and meso-xeric grasslands are rare, adapted to the Mediterranean climate, seriously endangered and host a high species richness. They are potentially achievable restoration targets because patches of these ecosystems remain in the Camargue area and close to the Cassaïre site. Moreover, an ecological history approach reveals deep human imprints on ecosystems and ensures that historical restoration targets (the state prior to human impacts) cannot be reached, because they are associated with hydraulic functioning (flooding of the Rhône and Durance) that no longer exists. The restored site is planned to be suitable for livestock grazing, thus presenting a new agricultural opportunity, while simultaneously offering new services, such as hunting.