Sciences, Eaux & Territoires (May 2011)
Restauration de la Tourbière de Landemarais, vingt années de suivi Landemarais peatland restoration : 20 years of monitoring
Abstract
Procéder à la restauration de la dynamique naturelle d’un écosystème passe par un suivi scientifique efficace des opérations et de leurs effets écologiques. Après vingt ans de suivi de la réhabilitation de la tourbière de Landemarais en Bretagne, quels sont les résultats sur le maintien des espèces et des habitats ? Quelles sont les améliorations à envisager dans les pratiques de gestion ?Resulting from terrestrialization of a pond built in Xth century, the telmatic wetland of Landemarais is an acidic mire, locally differentiated by local 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 states close to the previous ones. 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. Hypothesis of sod-cutting of the upper peat after woodland clearing is discussed.
