Land Transport Infrastructures, Ecosystems and Landscapes


Integration of the mitigation sequence (avoiding, reducing and offsetting impacts on biodiversity) into land planning policies
ITTECOP Apr 2017
Projet: Recherche
En cours


/ Organisation: MNHN
/ Organisation: MNHN


Weissgerber M., Roturier S., Julliard R., Guillet F., 2019. Biodiversity offsetting: Certainty of the net loss but uncertainty of the net gain, Biological conservation, 237, 200-208.

Integration of the mitigation sequence (avoiding, reducing and offsetting impacts on biodiversity) into land planning policies

The mitigation hierarchy is part of environmental assessment, applied to projects and programme plans, aimedatre conciling landuse planning and biodiversity conservation (among other environmental issues). This project questions the prospects for improving the instrument at the project level; and for contributing to the integration of biodiversity in land-use planning through the development of plans and programmes.

We show that avoidance (and reduction) actually concerns only 8% of the species inventoried on the area of the 25 linear infrastructure projects studied. The application of the mitigation hierarchy thus leads to a strong reductionism of biodiversity. “No net loss” target only a certain protected and threatened biodiversity. 80% of the biodiversity offset measures are carried out on naturalorsemi-natural sites where the potential for ecological gain is very low. The way the mitigation hierarchy is applied is thus not ecologically relevant. The challenge of rebalancing the hierarchy for better avoidance practices remains. On this specific point, legal analysis has shown
that the texts are vague and struggle to provide support for jurisprudence. It therefore appears necessary to define the areas that can be developed upstream, in order to avoid sites of biological interest and to have an overview of local land consumption.

However, the application of the mitigation hierarchy at the scale of plans and programmes appears to be weakly appropriate. For most of the 7 urban planning documents studied, the environmental assessment was carried out at the end of the document development process, and fail to contribute to integrate biodiversity in the political project and in the landzoning. Five determinants of the poor integration of biodiversity in planning processes have been identified: (i)the culture of planning perceived as priority to develop territories on the economic and demographic level and territorial engineering that is often limited in scope; (ii) the biodiversity interest,whichisseenasproportionaltotheecologicalcharacteristicsoftheterritoryanditsknowledge; (iii)the tendency to relegate environmental constraints to another scale; (iv) the administrative process in which biodiversity is only a marginal issue among others; (v) a lack of support linked to a change in public and territorial engineering where the reduction in fieldwork is likely to reach the threshold of counter-productivity.

To conclude, the legal framework and application tools already existand are available to territorial stakeholders to take biodiversity into account in land planning. However, public and territorial engineering does not have the means to bring environmental policies into qualitative implementation. However, the application of technical procedures weighs little in the front of the power of local officials involved in development and the prefect's exercise of arbitration.

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