Cost-effectiveness of Natura 2000 forest contracts for biodiversity conservation

Natura 2000 contracts in the European Union aim to maintain or restore natural habitats to a favorable conservation status. This article aims to analyze the cost-effectiveness of Natura 2000 forest contracts at the individual level of intervention areas in France. The level of long-term biodiversity was assessed using ex ante and ex post levels of conservation status, evaluated on a 100-point scale. Data collection was conducted on the contract areas using a combination of plotless and line intersection sampling methods. Cost-effectiveness was analyzed by modeling a cost function of conservation measures that is estimated simultaneously with the ex ante and ex post biodiversity equations. We performed an empirical illustration based on a small number of observations, and, therefore, the results deserve to be confirmed using larger databases. The conservation measures implemented in the contracts studied had a significant effect on maintaining and restoring biodiversity. Nevertheless, we found pronounced diseconomies of scale and low cost-effectiveness. This suggests the possibility of less ecologically ambitious contracts with lower average costs. Our results also recommend new targeting and prioritizing rules to implement more cost-effective conservation measures (e.g., veteran trees) in a less costly context (e.g., targeting main tree species in larger intervention areas). These recommendations could make Natura 2000 contracts significantly more cost-effective.