Où en est la France en matière de compensation écologique ?

In France, ecological compensation has existed since the 1976 Law on the Protection of Nature. Over the past decade, there has been a renewed interest in its application, though many questions still remain unanswered.. The choices of implementation systems and the effects they will have on the objective of no net loss (NNL) of biodiversity are not resolved. There is potentially a gap between the stated objective for compensation and these real effects when it is implemented. We propose to characterize it. We first describe the different systems for implementing ecological compensation that exist in France: Permitee Responsible Mitigation (PRM) compensation through the case study of the South Europe Atlantic High Speed Line (SEA HSL) and compensation through Mitigation Banks (MB) through the French Natural Compensation Sites (SNC). The article then puts these systems in perspective, with the principles of compensation to which they are supposed to refer. These examples compare the achievement of the following principles: the effectiveness of offset measures (ecological recovery, monitoring and control), the duration of offset measures, ecological equivalence and the proximity of the biodiversity offset sites to the impact sites. We show that in the case of SNC, having a large site with contiguous plots is not systematically verified. The larger the restored sites, the higher the recovery rate of ecosystems, especially for wetlands. Moreover, the sustainability of the compensatory measures seems relative because it has a limited duration of 30 years. In France, it can be observed in their application that the characterization of the MB system compared to the PRM clearing system is much less clear than in the United States. There are therefore two gaps: (i) between the statement of principles to which the different compensation systems respond and their implementation on the ground and (ii) between the NNL of biodiversity objective and the effects of the application of compensation. Finally, we put these systems in perspective with examples of emerging "territorial" approaches that could address a number of principles required to achieve the NNL