Jard quarry (Charente-Maritime), France — Study of colonizing species and compensatory measuresContext
Imerys Refractory Minerals Clérac carried out operations in the Jard quarry, in the department of Charente Maritime, in the 1970’s. The quarry is located south-west of Angoulême on the territory of Saint-Pierre-du-Palais village. The site extracted kaolin with an outstanding alumina content.
The site is to the east of a ZNIEFF type 2 zone and a Natura 2000 zone for the protection of the banks of the Lary and the Palais, the two neighboring rivers. The wetlands of Charente are rich in terms of biodiversity.
This former quarry, filled with water in the 1980’s, is now a wetland around which specific fauna and flora have established themselves.
Several key environments have been identified on the banks of Jard lake:
- vegetation of peaty moor and alder forest type colonized the areas around the pond. The siliceous soil is subject to flooding, favoring the development of myrica gale, a protected plant species of the Myricacea family.
- the banks of the pond are home to a reed field comprised of floating sedge and submerged bulrush that host Gomphus graslinii (a dragonfly protected by the habitat directive).
- on the hedges near the site, the red-backed shrike (species protected by the bird directive and on the National Red list) has been observed.
A specific study was conducted on myrica gale. Imerys Refractory Minerals Clérac set up measures to understand the plant’s living conditions and so protect its environment:
Three piezometers were installed to determine favorable hydraulic conditions for the plant. Similarly, a pluviometer located on the site complements those data.
Material from drilling is kept and studied to measure the H₂O content of the substrate.
The zone was marked out to confine it.
In addition, biodiversity is taken into account for any change in the site’s use.
In the long term, the study’s findings could be used to create a natural site for the general public.
- GEOARMOR research firm consulted on the developments to be carried out.