Assessing planetary boundary transgressions in China’s functional biosphere integrity

Accurately assessing the planetary boundary for China’s functional biosphere integrity is constrained by the scarcity of high-precision agricultural land-use data. To address this limitation, we reconstructed China’s historical cropping patterns based on our recently developed 1-km crop harvest area dataset and used these inputs to drive the dynamic global vegetation model LPJmL, enabling spatially explicit assessments of China’s functional biosphere integrity since the industrial period. We quantified the Human Appropriation of Net Primary Production (HANPP) and an ecological disruption metric (EcoRisk) to characterize the spatiotemporal evolution of functional biosphere integrity and its deviation from the Holocene baseline. We further identified China-specific planetary boundary thresholds and assessed the spatial heterogeneity of transgression patterns in terms of functional biosphere integrity. Our results indicated that the Huang-Huai-Hai Region and the Middle-Lower Yangtze Region experienced persistently high risks of boundary transgression, while Northeast and Southern China regions transitioned from a safe operating space to high-risk states during the mid-to-late 20th century. Notably, while HANPP has stabilized or declined in response to recent ecological policies, EcoRisk remains at a critically high level. These findings provide a valuable reference for assessing biosphere integrity in China and offer a framework for translating planetary boundary thresholds to regional scales.