OBSERVING NATURE AT THE MARSH OF BLONVILLE-VILLERS
Located between Villers-sur-mer and Blonville-sur-mer,
he swamp of 110 hectares is composed of wet meadows, canals and ditches is of great ecological wealth. Despite its proximity to the sea, it is a freshwater marsh fed by the runoff from four natural watersheds located on the surrounding hillsides.
The marsh is a space developed by man. Before the Middle Ages, this place was a vast reedbed of fresh water protected from the sea by a cordon of dunes. Then men dug canals to drain the land. The plots of land thus delimited were used for market gardening, the cultivation of cereals and especially for grazing. This human occupation created an environment of a beautiful ecological wealth. Today, this space is classified as a Natural Zone of Faunistic and Floristic Interest.
A sensitive natural area, partly protected (about 40 hectares) by the Conservatoire du littoral, the marsh has a diversified fauna and flora. In its meadows grow hygrophilous plants (supporting prolonged flooding), such as phragmites, rushes and sedges. This environment provides shelter, food and "resting place" for more than 150 species of birds, permanent residents or passing through on their way to their breeding grounds (in spring) or wintering grounds (in autumn). In the morning or at the end of the day, it is possible to observe and/or hear them. The tops of the poplars have been specially designed to allow the storks to settle and nest. Nationally protected species of amphibians and reptiles can also be observed here.
Nature tours and walks in Deauville
The agenda hereDISCOVER THE DIFFERENT ANIMAL AND FLORAL SPECIES OF THE MARSH
On the Villers-sur-mer side, there is a lake with playgrounds, benches, petanque courts and a bicycle rental service, as well as nearly 5 km of trails for walkers, cyclists and horseback riders.
A MARSH THAT LIVES IN ALL SEASONS
Grazing and mowing
The diversity of the marsh lies in the agricultural practices that take place there. Grazing allows, through the passage of cows, to maintain low vegetation levels favorable to many birds. By walking in wetlands, the cattle open the ground with their hooves and dig up insects that can be eaten by birds. Similarly, the dung is an excellent food source for other insects. In winter, the cows return to the barn. The marsh is often flooded and the grass no longer grows. However, the cows continue to feed on the marsh grass from the hay harvested in the summer. Mowing is done from July onwards to allow the birds to nest.
The 3 functions of a wetland
- hydrological > Wetlands contribute to the improvement of water quality: they have a purifying power, playing the role of a physical filter (they favour sediment deposition, including the trapping of toxic elements such as heavy metals, suspended solids...) and biological filter. They also regulate hydrological regimes: like sponges, they temporarily "absorb" excess rainwater to gradually return it, during periods of drought, to the natural environment (rivers located downstream). They thus reduce the intensity of floods and support the flow of rivers in periods of low water.
- biological > Wetlands constitute a fabulous reservoir of biodiversity, offering animal and plant species the functions essential to the life of organisms: feeding (concentration of nutrients); reproduction thanks to the varied food resources and the diversity of habitats; the function of refuge and rest, in particular for fish and birds.
- climatic > Wetlands participate in the regulation of microclimates: precipitation and atmospheric temperature can be influenced locally by the phenomena of intense evaporation of water through the land and vegetation that characterize wetlands.
Sources: Ministry of Ecology, Sustainable Development and Energy.
