Unveiling the Invisible Ecological Cost: Seasonal Biodiversity Footprint of Crop Rotation in China

Multiple cropping systems are widely adopted as a key climate adaptation strategy to ensure food security in China, however, they also impose significant pressure on freshwater ecosystems. While trade-offs between yield and water use are well-documented, the spatiotemporal impacts of specific rotation systems on aquatic biodiversity remain poorly quantified at fine spatial scales. To address this, we present a high-resolution framework integrating 30m-resolution crop rotation maps with monthly gridded characterization factors to quantify the potential fraction of species loss (PDF) at the grid level. This approach specifically distinguishes the impacts of seasonal rotation patterns from annual aggregates. We anticipate three key findings: (1) the identification of seasonal biodiversity hotspots driven by groundwater reliance in winter; (2) a quantification of the biodiversity leakage or savings resulting from China’s Crop Rotation and Fallow Policy; and (3) the revelation of spatial mismatches between agricultural intensification and ecosystem vulnerability. By shifting from a static, national-level perspective to a dynamic, spatially explicit one, this study underscores the urgency of incorporating seasonal biodiversity footprints into climate-smart agricultural policymaking to achieve food targets with ecosystem integrity.