In Geography, a marsh is a type of landscape formation , with the not very broken relief, where the ground is covered, permanently or intermittently, of a layer of stagnant water, in general not very deep, and covered of Végétation. One speaks about Wetland.
The vegetation of the marshes consists of species adapted to moist environment. Its composition varies according to the height of the Eau, the importance of the periods of draining, and according to the rate of salinity. The dominant species are the Poacée S (Roseau X), Typhacée S (Massette S), the Joncacée S (Jonc S), Cypéracée S (Carex), and others herbaceous and watery Plante S, and of the low woody plants. In the salt-water water marshes, one meets species Halophile S.
A marsh indicates a zone covered with marsh.
Formation of the marshesThe marshes are formed in zones badly drained by the hydrographic network, with impermeable basement. Located in not very broken zones, that is to say near River or the Mer, or private depressions of flow towards the sea (endoreism).
Ecosystem of the marshes
The water of a marsh can be fresh, stagnant, or more or less salted. The coastal marshes can be associated with Estuaire S or with Lagune S Littoral be.
The marshes shelter an important wild life. Poisson and Amphibians reproduce there and million insects is nourished there which emergent of this not very deep water. Out of water, these insects will also be used as food resource with the birds and bats until several kilometers of the zone, playing a considerable part on local fauna.
Today the marshes shelter very many rare species thus living only in the marshes, like Gratiole officinal, royal Pepper for the flora, the spangled Bittern, Marouettes or the Teal of summer for the birds and Campagnol amphibian for the mammals.
In the hot areas, they are often unhealthy because of the Paludisme, grave disease due to a parasite of the Sang whose life cycle passes by a Moustique stitcher, the Anophèle, but the Larve of the anophèle lives in stagnant fresh water. The Assainissement of the marshes makes it possible to fight effectively against paludism.
Valorization of the marshes by the manFor a long time, the man drained good number of marshes, difficult to exploit and considered unhealthy. The impact on the fauna and the flora but also on the cycle of water is considerable today and the majority of moist environments which were not destroyed are the object today protection measures.
Locally, on certain wetlands on the lighter ground and where water of the floods brings each winter of many nutritive elements, the man developed very productive cultures. It is the origin of the Maraîchage.
- Pole-relay interior wetlands
- Forum of the Atlantic Marshes Pole relay in favor of the littoral wetlands Atlantic Sleeve and the North Sea
- Gate wetlands
- Presentation of the marsh of Stors
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