Larger nations benefit more than smaller nations from the stabilizing effects of crop diversity

Abstract Diversifying crops has increasingly been recognized as key means to stabilizing national food production to a variety of shocks including extreme weather events. However, different nations may benefit differentially from this strategy simply because of the scale dependency of both crop diversity and yield stability. Using crop production data from 131 nations over six decades (1961-2020), we explore the spatial scale dependence of the crop diversity–stability relationship, drawing on new ecological theory and a range of complementary analytical approaches. Our results show that as the total national harvested area increases, yield stability and average crop stability within nations both increases. Crop diversity contributes to stabilizing national yield stability, but such stabilizing effects are weaker in smaller countries. Our findings suggest that enhancing crop diversity at the national level may not provide a de facto universal strategy for increasing yield stability across all countries, simply because larger countries can more easily buffer shocks.