Development of a standardized framework for the evaluation of biodiversity in the context of biodiversity offsets

In response to biodiversity erosion caused by human activities, biodiversity offsets are widely used to compensate for negative impacts with an objective of “No Net Loss” (NNL). One major challenge is to measure the biodiversity that will be impacted and compensated for. In most European countries and in France particularly, there are no recommended and available standardized indicators to measure biodiversity for offsets. This leads to heterogeneous practices with no guarantee of achieving NNL. In response to this fact we suggest a set of organized indicators to measure terrestrial biodiversity, which can be used in European and French offset programs to conciliate scientific knowledge, offset policies requirements and operational constraints that stakeholders have. To do this, we proceeded in four steps: (1) agreeing on a scientific definition of biodiversity; (2) Identifying the components of biodiversity targeted by the offset policy (3) developing a framework in which the relevant indicators will be organized and (4) prospecting for and selecting a set of indicators based on data collected on eight sites in France. We argue that the set of indicators address the legal requirements as well as the good practices recommended by the scientific sphere, while remaining operational for the stakeholders using it for their projects. It can also easily be adapted to other contexts where offset policy and ecosystems are different. Finally, we identify perspectives for losses and gains calculation, which is the next step to evaluate ecological equivalence between impacts and offsets.