The project aims to understand to what extent road networks and river networks are biologically connected, and what are the consequences of this connectivity on the biodiversity (plant communities) of these two landscape systems, both at regional and local scale. It will focus on the inter-network nodes that are the bridges, as strategic elements of ecological communication. By comparing the plant communities in place and the mechanisms of their structuration according to the stress gradients (stress and / or disturbance) of the two networks, we will establish homology models to predict the probability of occurrence and the level of resilience. species facing constraints. These gradients will be partitioned at the regional (upstream-downstream gradient) and local (transverse gradients at both corridors) scales. Local mechanisms (resilience, dispersion, interactions) will be analyzed more finely from in situ experiments on adult vegetation and diaspores (fruits, seeds), and molecular tracing of populations. Particular attention will be paid to ruderal and / or invasive species, as well as species of heritage interest. The final objective is to understand how the management modalities (roads, rivers) and the alteration of natural constraint regimes (rivers) contribute to exchanges, vicariance or species substitution between networks, and how this translates. in terms of taxonomic and functional structuring.
Recommendations will be made for the design and management of structures and corridors, with a view to better conserving existing biodiversity, or to considering satisfactory alternative evolutionary trajectories from the functional and operational points of view.