Les invasions biologiques dans le Parc naturel régional de Brière : présentation d'une recherche-action Biological invasions in the natural regional Reserve of Brière: applied research for management

Sur le territoire du parc naturel régional de Brière, les invasions biologiques ne sont pas un phénomène nouveau et les conséquences s’avèrent d’ores et déjà importantes écologiquement, humainement et économiquement. Des réflexions et expérimentations réunissant gestionnaires et scientifiques sont donc conduites localement afin qu’émergent des méthodes de gestion adaptées à la complexité des problèmes posés par les espèces invasives. The Marshes of Brivet and Brière, located at the north of the estuary of the River Loire, cover20.500 haregistered in the network of the sites Natura 2000 and mainly localised in the perimeter of the regional natural reserve of Brière (49 000ha). Among the pressures which are exerted there on the conservation of the biodiversity and the uses, biological invasions are not a new phenomenon but in 2 decades, it increased and now is currently regarded as a major problem. For the manager, the success of control and even more the eradication of an immigrant species depends on implementation of human, financial, scientific, technical means largely exceeding the territorial limits… and seldom joined together. However, the specific mono approach is confronted with the multiplication of invasive, animal and vegetable species, which increases the costs whereas the manager is in a context of limited means. The field manager must take into account huge ecosystemic changes, where inter specific exotic-native but also exotic-exotic relations appear; he solicits the scientists then. In collaboration, scientists and managers analyse the situation and test to pass from the complex management of invasive to the management of the complex of the invasive ones.