Tolypella salina R. Cor. on the French Atlantic coast: biology and ecology

Abstract Tolypella salina R. Cor. is a Charophyte only known from some French and Iberian stations. Its rarity and the specific richness of the salt marshes where it grows, on the Atlantic and Mediterranean coasts, have led to the proposal to add this species to the French list of protected plants. A survey of stations was realized on the Atlantic coast (Noirmoutier, Guérande) between 2010 and 2013 to complete the distribution map of this taxon. The aim of this work is to improve the knowledge of this plant’s biology and its ecological environment. It appears that the development of this species differs between stations, and also from one year to the next, a phenomenon due to the instability of its living environment (hydrological and salinity conditions, etc.). Phytosociological considerations related to the subassociation tolypelletosum salinae are added. Some recommendations are proposed for the management of these sites, taking into account the human activities there, in order to maintain the salt marsh mosaic that is necessary for the conservation of Tolypella salina.