Relaxing the production-conservation trade-off: Biodiversity spillover in the bioeconomic performance of ecological networks[Assouplissment de l'arbitrage production-conservation : les retombées de la biodiversité dans la performance bioéconomique des réseaux écologiques]

Ecological networks (ENs) aim to accommodate production and conservation within landscapes by shaping the spatial scope of conservation policies based on ecological criteria. The environmental effectiveness of these networks has been extensively studied; however, it has rarely been linked to their economic cost. This paper investigates whether EN-based spatial targeting relaxes the production-conservation trade-off and, if so, what the processes underlying its performance may be. We design an EN at the national level (France), with common farmland birds defined as a conservation goal and grassland expansion defined as a conservation lever. A dynamic, mechanistic, ecological-economic model simulates policy scenarios up to 2050 with alternative targeting strategies, including the EN. The results reveal that EN targeting is almost twice as cost-effective as a nationally homogeneous policy and about as cost-effective as focusing on biodiversity reservoirs, but with higher biodiversity gains. These outcomes rely on higher initial bird abundance in targeted regions, as well as positive feedback and spillover supported by bird dispersal. However, the EN's superiority only appears in the medium term because of ecological inertia. These interdisciplinary insights on a tool from ecology and conservation biology echo policy needs for the design and implementation of sustainable landscape management strategies.