Plant diversity as a component of the ecological performance of motorway planning: case study of Mont-aux-Liens (A19).

Abstract

Regulations and societal expectations are now encouraging land developers to assess the environmental impacts of their construction projects, but also to plan measures and actions to create or restore the biodiversity of modified areas. However, ex-post assessment of restoration or creation projects requires appropriate methods and materials. The "Mont-aux-Liens" case study, a landscaping development adjacent to the A19 motorway, showed that plant species diversity was a good indicator of ecological performance of such a development. Quantitative assessment (specific richness) shows better results than those expected initially but qualitative assessment reveals that few sown species have settled and that the site is highly colonized by exogenous species. Ecological characteristics and adaptative strategies of the flora explain these results. They provide useful information for redefining objectives adapted to improving the ecological performance of the planning, from the point of view of plant biodiversity.