Optimal allocations of agricultural intensity reveal win-no loss solutions for food production and biodiversity
Résumé
Reconciling biodiversity conservation and food production may require the fine-tuning of both agricultural intensity and its spatial allocation. Here, we explored whether the optimization of allocation of intensity could improve food production and biodiversity outcomes. We developed a spatially explicit, multi-criteria optimization model for agricultural intensity allocation at the scale of France and at the resolution of small agricultural regions (SARs) with a mean area of 669.6 km2. Three thousand allocations were randomly simulated and then optimized under three scenarios: intensification, extensification, and reallocation. Optimization was based on food production and biodiversity outcomes using several metrics, such as habitat specialization and trophic level, that reflect the composition of farmland bird communities. The optimization was based on derived statistical relationships between intensity and the production and biodiversity metrics at the SAR scale using national agricultural statistics and bird census data. Simulations showed that optimal allocations modulated the trade-off among criteria and led to increased efficiency, with optimal extensification increasing biodiversity and minimizing production losses. Furthermore, we revealed “win-no loss” solutions. For example, optimal intensification increased production with almost no biodiversity loss and optimal reallocation benefited biodiversity with almost no cost to production. A variety of agricultural intensity levels were necessary to maintain a diversity of farmland bird communities at the national scale. Although we demonstrate that optimal allocation of intensity can be a powerful means of reconciling diverse criteria at the national scale, its implementation will require new mechanisms for spatially targeted and coordinated policies.