Abstract
The coastal areas of Nord-Pas-de-Calais are made up of a mosaic of natural environments which are very diverse but heavily subjected to disturbances linked to human activities, which leads to a strong fragmentation of the natural habitats. These environments are however home to a fraction of the populations of two iconic pioneer amphibian Nord-Pas-de-Calais species: the natterjack toad (Bufo calamita) and the common parsley toad (Pelodytes punctatus), which find their original habitat there. Paradoxically, the growing anthropization has also created new habitats which are conducive to colonisation by pioneer species, to some extent during industrial exploitation, but much more intensely after it was abandoned. The coalfield example is striking: the mining and related activities have led to the establishment of secondary habitats which are purely anthropogenic in origin but provide favourable conditions for the reproduction of amphibian species. Among them, the natterjack toad and common parsley frog who, initially present in original coastal and meadow habitats, have progressively colonised the “industrial habitats” of the mining area of northern France, which were abandoned after the mining activities ended. This research project aims to (i) evaluate and contrast the levels of diversity and neutral and adaptive genetic differentiation in the native populations and the populations having recently colonised the mining area sites, and (ii) to understand how the gene flows between populations establish themselves in those two amphibian species. An analysis of the genetic composition of egg-laying is also proposed, to describe those species’ reproduction system and quantify its influence on the effective size of populations and on the levels of inbreeding. According to the knowledge of the genetic diversity of populations and its spatial and temporal dynamic, some conservation strategies for the species and their habitats will be proposed, in an on-site precautionary management perspective but also in a landscape ecology framework in relation with the regional ecological coherence plan. From an applied point of view, this project’s expected results fit into a regional action plan policy which will be immediately operational and aimed towards the technicians, decision-makers and ecologists involved in the spatial planning of Nord-Pas-de-Calais.
France