Normandy, France case study

BRANCH used seven case studies in Basse-Normandie to assess how climate change may affect coastal biodiversity. The study sites included sand dunes, saltmarsh, mudflats, grazing marsh and reed beds.

BRANCH models show that mudflats, dunes, wetlands and freshwater ponds are the most vulnerable coastal habitats to climate change. Sand dunes are eroding on all the study sites. Dunes help to protect wetlands and freshwater ponds from salinization and flooding by the sea. Rises in sea level may make the erosion worse.

Saltmarshes are currently expanding at all the study sites, in contrast to the UK case studies, but this may be halted by sea-level rise. There are also high rates of sedimentation.

There are opportunities to protect intertidal habitats. Loss of habitat could be partly compensated by habitat re-creation through managed realignment. But this could lead to new conflicts for space between different protected habitats and with land use, particularly agriculture.

BRANCH has provided guidance to help stakeholders manage and plan for climate change. This includes:

• Reports summarising current wildlife and coastal dynamics at case study sites and considering how these are likely to change in the future.
• A new flexible mapping tool for planners, to help evaluate land use decisions for the coast. This includes habitat and species datasets.

This mapping tool:

• Can show maps of vulnerability to sea-level rises of 50 and 100cm.
• Forms a baseline for a long-term monitoring program at the study sites.
• Takes into account current uncertainties of climate change impacts and will evolve to integrate developments in knowledge on extreme climate events.

A further detailed report on the study sites and model outputs is available in French only.

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