Preserving peri-urban land through biodiversity offsets: Between market transactions and planning regulations

Competition for land use is a severe problem in peri-urban areas where available land is scarce and is also targeted for different purposes such as construction, local food systems, recreational areas, and biodiversity offsets. In this context, mitigation policies can be considered like innovative planning regulations, in order to neutralize land development impacts and sustain ecosystem restoration and conservation. The policies may lead to the production of biodiversity offsets, which are secured pieces of land where ecological restoration is carried out as a way to compensate for impacts. In this way, biodiversity offsets appear to be a viable option to maintaining natural areas in peri-urban areas in the long run. This article examines the different ways to deal with land availability and access to offset sites through the analysis of land strategies developed by public and private intermediary actors involved in the implementation of mitigation policies, and the consequences on the ecological quality of offsets. Based on a sociological survey of 20 case studies and 95 interviews conducted in 2019-2021 in six French regions, the article identifies three situations that rely on different balances between market transactions and planning: (i) private intermediaries and municipalities who coordinate to offer land solutions to developers; (ii) access to land for biodiversity offsets stems from private land transactions which can lead to temporary mobilization of land and thus to ecologically precarious solutions; (iii) attempts by municipalities to include offsets in planning policies. Finally, if municipalities do not intervene to identify and set aside dedicated land, biodiversity offsets will remain temporary and limited in their capacity to conserve biodiversity.