The Camargue Biosphere Reserve covers 193 000 ha, including 50% of natural and semi-natural habitats dominated by lagoons, brackish/freshwater open and reed marshes, halophilous steppes, rangelands and fallow lands. Resilience of these ecosystems to anthropogenic influences is variable and can translate into alpha, beta and gamma biodiversity loss through ecosystem fragmentation and transition (eg, from halophilous steppes to reed marsh following freshwater input), and modification of ecosystem health state with feedbacks on ecosystem services, especially in terms of human uses (waterfowl hunting, bull grazing, reed harvesting, nature conservation). These natural ecosystems are intermingled with agro-systems of which the evolution from family to speculative farming is likely to affect biodiversity. The delta is almost completely polderized, and each year about 400 000 000 m3 of water is pumped from the Rhône to permit rice cultivation (and incidentally water management of marshes and pastures), of which 55% is pumped back to the Rhône, the rest being evacuated (when possible!) to the sea through the Vaccarès lagoon. Sea level rise, climatic variability, modification of agricultural policy (affecting rice farming areas), freshwater availability (increased penetration of the saltwater wedge from the Rhône) and underground salinisation will differently affect these ecosystems of which the dependency upon the hydro-system, primarily developed for rice production, is variable. Considering the high degree of 'artificialisation' of the delta, research and transfer activities at Tour du Valat are mostly targeting human behaviors, since we consider that management actions have currently more impact than evolution of abiotic conditions on ecosystems. Our mail goal is to foster adaptation of users, managers and decision makers to global changes.
The Tour du Valat (TdV) is a private research centre located on a 2 600 ha estate (of which 1 800 ha are classified in natural reserve) in the Camargue (Rhône delta), south of France. Created in 1954 and legally recognised as a non-profit-making association, it has set itself the mission to halt and reverse the destruction and degradation of Mediterranean wetlands and their natural resources, and promote their wise use. Pioneer in producing management plans for protected natural areas, its activities are today largely oriented towards multidisciplinary research, co-constructed with or transferred to stakeholders and aimed at preserving the biodiversity, functions and services provided by ecosystems in a context of global changes. Disciplines such as hydrology, remote sensing, plant and animal ecology are combined into three main ecosystem approaches corresponding to modeling, restoration and management. Tour du Valat collaborates with managers, users, research organizations, and administrations. The Biosphere reserve provides a framework for collaborative projects across the entire Delta. Operational decisions are made by the Management Committee, the Technical Committee (made up of partners and stakeholders of the site), and the Scientific Council (involving researchers from Tour du Valat).
