Monitorage de la biodiversité urbaine par l’établissement d’un bilan évolutif du capital naturel existant dans les projets

With the general observation of massive and recent disappearance of biodiversity caused essentially by human activities of transformation and exploitation of natural terrestrial and aquatic ecosystems, the establishment of a general concept of ecosystem restoration becomes essential at the scale planetary. Publications proposing ecosystem approach strategies aimed at restoring biodiversity in all environments exploited by man are multiplying but most often use strongly anthropocentric visions of nature’s ecosystem services. With the need for nature in the city, recognized for a good ten years, green city projects are multiplying and encouraging many developers to follow ecological labeling concepts. They are particularly encouraged to do so in France by the new Climate and Resilience law (2021) and the application of the Zero Net Artificialization (ZAN) objective which provides for the restoration of degraded ecosystems in urban environments, respecting in particular the “Avoid – Reduce – Compensate” sequence  as provided for by the impact study procedure. The environmental modelling of the buildings and exterior fittings of a project is possible based on the analysis of the ecological potential developed successively by each element and then by the entire project site. Thus, in each development project, the share of «Natural Capital» resulting from the integration of known environmental constraints and ecological developments implemented by the project is evaluated. The result is a working methodology which establishes rules for analyzing and evaluating in stages the possible ecological contributions in the multiple situations that arise during the development of construction projects. This modeling of the overall ecological efficiency of a site, based on the factorial weighting of Quality, Capacity and Functions, allows the evolutionary monitoring of the ecological value obtained by the stages of construction and long-term management of the urban natural spaces. Beyond the aspects of biophilia and the know-how of the builders attested by labels, it above all attests to the quantified importance of the contribution of a project to the natural capital of the urban environment concerned.