Biodiversity-food trade-offs when agricultural land is spared from production

The Kunming-Montreal Global Biodiversity Framework proposes to address biodiversity decline by expanding areas under conservation. Biodiversity conservation in agricultural landscapes, the world’s predominant land use, could involve sparing, or setting aside, agricultural land from production, implying biodiversity-food trade-offs. Employing bird species and agricultural data, we undertake a novel empirical analysis of such trade-offs on a set-aside scheme implemented in England between 1992-2007. Expanding set-aside increases bird species abundance and richness by, respectively, 1.2-2.1% and 0.7-0.9%, but has no impact on diversity (Shannon-Wiener index). These effects are discontinuous, subject to thresholds in set-aside areas. A minimum 3% of agricultural land set aside is required for a positive effect on biodiversity while 13% of agricultural land generates a 15-25% and 30-35% increase in abundance and richness, respectively. Estimates of short- and long-run effects show that impacts are larger in the long-run. Expanding set-aside is also associated with a 10-17% decline in cereal output, with weak evidence of an attenuating land-sparing effect on yields. Our results suggest that although biodiversity-food trade-offs are likely in high-yield agricultural landscapes, such as those in England, the risk of a reduction in food supply could be minimised in settings where there is still scope for intensification.