Restoring fen habitats of Northern France and Belgium in the Anthropocene

PROJECT DESCRIPTION

BACKGROUND

Since the Holocene, alkaline fens have significantly expanded in the Paris Basin due to the presence of limestone bedrocks and the associated chalk groundwater aquifers. This particular context generated a great diversity of hydrogenetic wetland types, such as typical topogenous fens, sloping spring fens, coastal fens and, most importantly, fluviogenous valley fens. Despite their apparent homogeneity, these habitats show a trophic and a biogeographical gradient from the Atlantic to the Continental region. The specific background of each site also contributes to the diversification of fen successional seral stages, from pioneer semi-aquatic to mature forest habitats.

For several centuries, the Paris Basin has experienced one of the most important expansions of human activity in western Europe. As a consequence, primeval fens were heavily impacted by peat and groundwater extraction for domestic and agricultural use. The small fen communities that have survived until the so-called Anthropocene are now facing the combined effects of the abandonment of traditional agricultural practices and an ever-increasing anthropic pressure. The resulting artificialisation of wetlands is a major cause of drying and eutrophication of fens, which prevents the conservation of species and habitats.

OBJECTIVES

The conservation of fen habitats in the Paris Basin, both in northern France and southern Belgium, represents a major challenge for the protection of biodiversity. The overall goal of the ANTHROPOFENS project is to restore 480 ha of these habitats (totalling 35% of their total surface area known in the regions Natura 2000 network sites) to a favourable conservation status, by (i) implementing appropriate eco-hydrological management, (ii) developing and promoting integrated practices adapted to the successive seral stages of the targetedhabitats (e.g. extensive grazing), and (iii) re-establishing ecological continuity between Natura 2000 sites.

The projects actions aim at restoring the wetlands ecosystem provisioning and regulating services, while improving their resilience to future perturbations, including the effects of climate change. This project also aims at engaging all relevant stakeholder groups, to ensure an integrated and common approach to fen habitats conservation. The project will directly contribute to the implementation of the Habitats Directive.

RESULTS

Expected results:

improvement of the conservation status of 13 fen-related Natura 2000 sites (15 000 ha) in northern France and southern Belgium, considered to be biodiversity hotspots of the Paris Basin These sites include the main remnants of the following habitats of Community interest: - alkaline fens (475 ha); - calcareous fens with Cladium mariscus (222 ha); - transition mires (95 ha); - fen meadows with Molinia caerulea (122 ha); - bog woodland (64 ha); and - alluvial carrs with Alnus glutinosa and Fraxinus excelsior (406 ha).

All of these habitats conservation status are currently evaluated as Unfavourable. By the end of the project it is expected that:

the eco-hydrological dynamics of at least 10 typical sites from each of the main fen systems is understood and can be used as a showcase for nature conservation professionals and policymakers;

the project team and at least five stakeholders are trained in the fundamentals of eco-hydrology;

alkaline groundwater is stored in ecologically-strategic locations (circa 180 ha on 6 sites), so as to supply Alkaline fens and Calcareous fens with Cladium mariscus habitats;

six sources of pollution are controlled to reduce eutrophication and/or mineral sedimentation of meso-oligotrophic fen habitats (Alkaline fens, Calcareous fens with Cladium mariscus);

1 800 m of Transition mires habitat on land-water interface areas (a pilot site) are restored;

32 ha of woodlands are managed specifically for Bog woodland, and Alluvial carrs with Alnus glutinosa and Fraxinus excelsior, habitat restoration, to allow the maturation of late successional stages;

195 ha of open herbaceous vegetation are restored to favour open fen habitats;

18 ha of mid-successional habitats and poplar plantations are converted into fen meadows and pastures at two locations;

decision-making, planning and evaluation tools are developed and disseminated (e.g. website, publications, workshops) to promote good management practices;

stakeholders (local decision-makers, hunters, fishers, etc.) are better aware of the challenge of restoring fen habitats; and

a technical and administrative framework to implement and/or expand non-conventional grazing by large herbivores is designed and tested.