Biological invasions in the natural regional reserve of Brière: applied research for management

Abstract

The Marshes of Brivet and Brière, located to the north of the Loire estuary, cover 20.500 ha included in the network of Natura 2000 sites and mainly located within the regional nature park of Brière (49 000ha). Among the pressures exerted on the conservation of biodiversity and uses, biological invasions are not a new phenomenon but one that has intensified over tha past in two decades and is currently regarded as a major problem. For the manager, the success of control - and even more so the eradication - of an introduced species depends on a complex implementation of human, financial, scientific and technical means largely exceeding the territorial limits... and seldom combined. However, the mono-specific approach is confronted with the multiplication of invasive, animal and plant species, which increases the costs while the manager is faced with limited means. The field manager must take into account profound ecosystemic changes, where interspecific relationships between introduced-native but also introduced-introduced species are being established, he then solicits the scientists. In collaboration, scientists and managers analyse the situation and experiment in order to pass from the complex management of invasives to the management of the complex of the invasives.