Take a tour via
-Report: on the Care-Peat impact within Landemarais peatland (Main Output)
Summary Landemarais
The investment workpackage WP I7 corresponds to the restoration works undertaken in the French site Landemarais. Located at an altitude of 145 m in the commune of Parigné in the Massif Armoricain, the Landemarais peatland is owned, managed and labelled as a "Sensitive Natural Area" (Espace Naturel Sensible - ENS) by the Ille et Vilaine County Council. It covers an area of 26 ha, essentially composed of sedge meadows, Molinia caerulea, ericaceous shrubs and a pond, with local sphagnum patches. The climate of the Landemarais site is oceanic.
The restoration works in Landemarais peatland consisted in stripping the first 10 to 20 cm of peat in 2 areas of approximately 20 m x 20 m, where the vegetation was dominated by Carex paniculata. This plant decreases biodiversity (almost monospecific areas) and probably promotes C losses. The excavated peat (full of seeds of Carex paniculata) was placed in the wooded buffer area of the peatland, between the lateral canal and the peatland itself. In addition, Sphagnum patches were set up. Sphagnum plants were collected from intact area to do 1) dense patches when the situation was not too aquatic, and 2) floating mats when the system was permanently aquatic. To do the dense patches, Sphagnum mosses were taken outside the area to have enough materials to set up 6 dense patches in the less aquatic restored plots. They consisted in squares of 50 cm x 50 cm surrounded by cotton string to make the patch stable. Bamboo sticks were used to installed the cotton string and to serve as supports for Sphagnum. Floating mats were made of cork and hemp to support the Sphagnum plants.
Collars for the GHG fluxes monitoring were installed. To access to the different measuring plots, removable walkboard were constructed by the CD35. Thanks to these walkboard, measuring can be done without trampling of the site. When possible, nets were used to assess the response of the system to varying radiation intensity. In the restored area, the measurements were made in bare peat plots (n=3) and in Sphagnum patches (n=3). In the control area, the measurements were made in bare peat plots (n=3) and in Carex paniculata tussocks (n=3).
The first results of CO2 fluxes show that Carex paniculata plots, in spite of being a large CO2 uptake, tends to functions as a source of CO2 most of the measuring times because of a high ecosystem respiration. Also, the restored area functioned as a sink of CO2 during most of the measuring period. This highlights a positive effect of the restoration works on the CO2 fluxes during this first year.
Setting up a pilot site in the Landemarais peatland was not only important to test restoration actions on C sink capacity in this specific site, but also a tool to communicate to managers and public on the necessity to restore peatlands. A workshop was organised in October 2023. A wide array of people with different interest was reached during these workshops, spanning from site managers to private companies.