Pilot site La Guette
A brief tour of the pilot sites via:
-Report: La Guette as a showcase to promote Carbon sequestration in French peatlands (Main Output)
Summary La Guette
The Guette peat bog is located in Neuvy sur Barangeon, 200 km south of Paris. The site is drained by a ditch dug along a road at the bog's outlet. This disturbance lowers the water table and increases its fluctuations. These hydrological changes favor the occurence of common pioneer species (Molinia caerulea, Betula spp) to the detriment of typical bog species (e.g. Eriophorum spp, Rhynchospora spp), including Sphagnum, a moss considered an engineer species and a major contributor to peat deposition.
Restoration work began in 2014 as part of a project funded by the Centre-Val de Loire Region.The work focused on the site's hydrology (reducing the rate at which water leaves the system) and vegetation (transplnatation of spahignes).Results showed the positive effect of adding Sphagnum on C fluxes and vegetation in small plots (2m x 2m).The Interreg NWE CARE-PEAT project extended the first restoration experiment, stripping the peat from the top 5-10 cm in plots of around 20 m x 30 m in 2 hydrologically contrasting areas (total 1200 m2). Appropriate equipment was used to avoid any irreversible damage to the site. Excavated peat (full of Molinia caerulea and ericaceous shrub seeds) was placed at the edge of the bog to form a dam, where these common species are already present along with Betula spp. The dam can filter water from upstream and prevent Betula spp. that have been cut from growing back from their trunks.
Sphagnum mosses were collected to make two types of patches: 1) dense patches from an intact area, 2) sparse patches from a strand-by-strand transplant of Sphagnum moss. One of these two situations can be chosen depending on the initial amount of Sphagnum moss in the site to be restored. If sufficient sphagnum remains, the dense patch solution can be chosen. If few individuals are present, then strand-by-strand transplanting should be chosen.
The dense patches managed to maintain themselves over time and to develop. This technique, which promotes the survival of sphagnum mosses, therefore seems promising. The patches with strand-by-strand transplants did not withstand the sucessive droughts. Almost all the individuals died. In view of the recurring drought conditions, dense patches are therefore to be preferred.
Finally removable wooden walkboards were then installed to enable the various monitoring operations to be carried out.
The first results showed that peat stripping induces the growth of several plant species typical of bogs, as well as an increase in floristic diversity. Furthermore, the Sphagnum patches tend to function as a C store, compared to a control adjacent area dominated by Molinia carulea. In the long term, these management actions, combining actions on hydrology and vegetation, could increase the area's capacity to store carbon.