Evolution of the heritage identity of salt-marshes subjected to the submersion risk along the Pertuis Charentais coasts – PAMPAS

PAMPAS focuses on the future of the coastal marshes of Charente-Maritime and their management against the marine submersion hazard. This project chooses to tackle this issue through a focus on the heritage identity of those marshes to go beyond the classical approaches of conservation ecology, standard economy and conservation of cultural heritage, all considered insufficient to apprehend the heritage, understood as the particular articulation between the components of a marsh that contribute to build its collective identity. PAMPAS therefore aims to lift this lock by an interdisciplinary approach applied to three study areas (the marshes of Fier d'Ars, Tasdon, and Brouage), contrasting both in terms of natural, cultural, landscape heritage and management (dikes, in project of reopening to the sea, in debate of laissez-faire or diking, respectively). PAMPAS is built on a collective approach (co-coordinated by four researchers) and uses participatory methods to foster interdisciplinary between Social Sciences, Life Sciences, Earth Sciences (48 people from 13 units, 9 disciplines) as well as with managers of marsh areas. It focuses on three major objectives: 1) to characterize the natural functions (biodiversity, biogeochemical functioning and ecosystem functions), cultural (heritage trajectory of property) and landscape (recognition landscape elements by the users and development) of the marshes and integrate these different components into a spatial representation of the heritage identity; 2) define from the socio-ecosystem point of view, the response of these components to the marine submersion hazard: after having characterized physically the submersion hazard, the study of the short-term effects on the heritage components will help to develop a global representation of the socio-ecosystem both in terms of functionalities, services, but also in terms of resilience or ability to adapt to the hazard. The effects at the 100-year scale will also be addressed through the past evolution of territories characterized by contrasting hydrodynamic contexts. Finally, 3) these results will be confronted with the different management practices on the selected sites in order to define evolution scenarios of their heritage identity and evaluate their adaptive potential. This axis includes (i) an analysis of the management methods determining the possible evolutions of the patrimonial identity, following the submersion, (ii) a discussion of the results with managers and the locally elected representatives, using an interactive tool of cartography and focus groups, to discuss the transition of these territories and adaptive management modalities of marshes, and (iii) dissemination of results towards users and the general public to feed an ecosystem vision of marshes exposed to marine submersions. Finally, and based on a revised definition of patrimonial identity adapted to marsh areas, PAMPAS will bring new solutions for sustainable management, by transmitting economic, cultural and ecological knowledge. The stakes and the project issues therefore go far beyond the local level and concern wetlands at the global level for which it is now necessary to review the analysis and management frameworks by integrating the heritage into its various social and ecosystem dimensions. Thus, the project fits naturally into the "Dynamics of ecosystems and their components for sustainable management" stakes of the ANR.