REWANS
REWANS: Restoration and rewilding of aquatic ecosystem corridors through large-scale Nature-based Solutions
Scientific supervisor: Loïs MOREL
Host institution: Institut Agro Rennes-Angers
Context
Waterscape ecosystems – the continuum of aquatic and riparian habitats connected by groundwate – rare among the most vulnerable to global changes. Yet they provide essential ecosystem services (NCPs) such as hydrological regulation, mitigation of climate extremes, water purification, carbon storage, as well as supporting biodiversity and food production. Despite ambitious historical conservation policies (laws of 1992, 2004, the Water Framework Directive, etc.), the ecological restoration of these environments has remained fragmented and struggles to integrate landscape dynamics and multiple pressures.
The project
REWANS proposes to address these challenges by shifting the scale of action: restoring waterscapes at the watershed level by combining several Nature-based Solutions (NbS), designed to alleviate pressure, facilitate agroecological transition, and promote functional restoration, and deployed along a rewilding gradient (urban, agricultural, and natural areas).
The project takes an interdisciplinary approach, combining ecology, biogeochemistry, hydrology, geography, and the social sciences. It draws on a unique corpus of data and citizen science, rarely combined in an integrated approach, supplemented by new field observations and innovative monitoring methods, both integrated into a FAIR hub. These data will enable the establishment of detailed links between landscapes, NbS, and NCPs, and the production of multi-scale, predictive, and operational assessments.
Based on this data, a typology of NbS will be developed, and their effects on key NCPs will be quantified using multiscale analyses. Predictive models will then be used to simulate restoration scenarios under different climate and land-use trajectories, in order to identify optimal combinations of NbS at the small watershed scale. These models will be validated using new data collected at pilot sites in Brittany, a region with a wide gradient of human impact, by combining integrated monitoring of habitats and communities with measurements of biogeochemical fluxes (particularly CO₂ storage and sequestration), ultimately leading to the development of a simple and accessible landscape quality index. Finally, concrete restoration pathways will be tested and co-developed with local stakeholders, leading to operational roadmaps for each watershed and laying the groundwork for a future Living Lab network dedicated to the restoration of small watersheds.
REWANS will deliver a groundbreaking overview of NbS in France, simple and robust indicators, a scalable decision-support tool tailored to small watersheds, and a full-scale pilot project in ecological governance.