Land sharing strategies for addressing the trade-off between carbon storage and crop production in France

Carbon storage (CS) is essential in mitigating atmospheric CO2 levels, but crop production (CP) contributes to food supply. Land management requires understanding the trade-offs between these important, but conflicting, ecosystem services. We studied land use-based strategies to identify the optimal balance between the two, in particular investigating the role of agricultural intensification. We calibrated a statistical model that linked land cover, land use, climate, and biophysical variables to CS and CP in France at 10 km by 10 km resolution. We designed four optimization scenarios: maximisation at the country scale of (1) CS; (2) CP; (3) joint optimization of CS and CP; (4) same as (3) but with minimization of total energy input. The mono-objective scenarios, (1) and (2), enhanced one ecosystem service while decreasing the other. In scenario (3), both ecosystem services were increased at the same time (+ 2.1% for CS and + 9.6% for CP) with a land sparing approach (decrease and intensification of annual crops and increased forest). In scenario (4), the minimization of energy input resulted in less of an increased in both ecosystem services compared to scenario (3): + 1% for CS and + 1.5% for CP. This scenario promoted a land sharing strategy with enhancement of heterogeneous agricultural land. The good performance of the land sparing approach comes at the cost of a high energy use; on the contrary, the land sharing approach allows improvements that, although more modest, come with energy input minimization. As a vast body of literature stresses the biodiversity conservation value and the positive social impacts of land sharing approach, we argue that scenario (4) is more sustainable.