Landemarais peatland restoration : 20 years of monitoring

Abstract

Resulting from terrestrialization of a pond built in Xth century, the telmatic wetland of Landemarais is an acidic fen-land community, locally differentiated by ombrotrophic bogs. Linked to peat digging, particularly in 1968, the drainage has amplified the woodland dynamics. Integrated within the ENS ("Espaces naturels sensibles") network of the Conseil Général 35 in 1989, the objectives of peatland restoration were recovering open areas after woodland clearing and peat rewetting. These two actions had to be performed for re-initialisation of natural dynamic trajectories, already existing before disturbances. The targeted species populations and peat plant communities have recovered a steady state close to the reference state (pre-1967). Nevertheless the managers have to face the woody species encroachment, such as Betula and Salix, by cutting and / or digging them every 2-4 years in order to maintain open habitats for conservation of the peatland target species and plant communities. A hypothesis of sod-cutting of the upper peat after woodland clearing is discussed.