In its Plan d’Actions Quinquennal (PAQ Cen Normandie Agrégat des PAQs cenno et CenNS), validated by obtaining its State-Region HN approval on September 11, 2014, the Conservatoire d’espaces naturelles de Normandie (Seine) included land management in its protection actions as one of the strongest and obviously sustainable tools. It is in this spirit that it has drawn up its land strategy and in particular identified natural and semi-natural environments, species and habitats and priority areas to be controlled for the purpose of their preservation and in the general interest.It is stated in the same AQP that are PRIORITARY: • the calciculture and sandy slopes of the alluvial terraces for the activities of the Cen because these habitats host an exceptional diversity in terms of faunistic and floristic richness (very numerous protected species, presence of 2 regional endemic plant species, many species at range limit, heritage plant formations...).• Wet meadows and marshes: the location and quality of wet meadows and marshes of high ecological value are still very poorly known in Normandy. Peat and paraturbous meadows, lean mowing meadows, and acidocline meadows appear to be the rarest. These areas are seriously threatened with disappearance, in a general context of the destruction of Norman meadows.In addition, the network of Conservatoires of Natural Spaces has set up a Fund of Dotation within which it can secure any land in such a way as to render inalienable the conservation vocation of the spaces in question. The Cen Normandy may transmit these acquisitions to the Fonds de Dotation des Conservatoires d’espaces naturelles while retaining the mastery of use, management and conservation. This endowment fund is intended to become a Public Utility Foundation in the coming months.Finally, the law to win back the biodiversity of nature and landscapes of August 8, 2016 created the possible contractualisation of Real Environmental Obligations (ORE). This contract between an owner and a public authority, a public establishment or a legal entity governed by private law acting for the protection of the environment allows the owner to give his property a lasting environmental vocation without losing ownership of it. The Cens, by virtue of their social purpose, their missions, their approval may contract with any voluntary owner.In this context, the Conservatoire plans 23 shares of acquisition or contractisation of Real Environmental Obligations of Natural Heritage Areas for a total of 188 ha 65 to 09 ca.These projects all present natural heritage elements of regional, national or international interest:- Species from the red lists of Normandy- Species concerned by a Regional or National Action Plan- Habitats listed in Annex I or Annex II to the Habitats Directive