Bio-economic models to design viable agri-environmental schemes in France

Abstract

Significant declines in farmland biodiversity have been reported in Europe for several decades. Agricultural changes have been identified as a main driver of this erosion. Although different agri-environmental schemes have been implemented, their positive role on biodiversity remains in question. This raises the question as to how to reconcile farming production and biodiversity conservation in order to operationalize a sustainable and multifunctional agriculture. To deal with such issues, the present paper proposes a bio-economic model and an analysis based on a co-viability perspective. The co-viability approach intends to extend the Population Viability Analysis to bio-economic risk. The model couples stochastic dynamics of both biodiversity and farming land-uses selected at the micro level with public policies at the macro level based on financial incentives (taxes or subsidies) for land-uses. The co-viability approach makes it possible to evaluate bio-economic risks for these public incentives through the probability of satisfying a mix of biodiversity and economic constraints throughout time. The model is calibrated and applied to metropolitan France at the SAR (small agricultural regions) scale using a community of 34 common birds. We identify different public policies and scenarios with tolerable agro-ecological risk on the time horizon 2050. Our results suggest that some combinations of taxes on cereals and subsidies on grasslands could be relevant to develop a multifunctional agriculture. Moreover, the flexibility and multi-criteria viewpoint underlying the approach can be fruitful for decision makers in the context of adaptive management.