Global oilseed trade links cultivated land conservation in China to worldwide land savings

International trade increasingly redistributes natural resources, effectively displacing environmental pressures across borders. As the world's largest oilseed importer, China's consumption significantly impacts global land use, yet the structural evolution of this trade network and its specific consequences for cultivated land protection remain unclear. To bridge this gap, this study adopts a metacoupling framework to examine the evolution of major oilseed trade patterns from 2010 to 2023 and their multi-scale impacts on cultivated land. By constructing a time-series global trade network and integrating it with virtual land flow modeling, we systematically examine how trade structures influence land resource allocation at both the domestic (China) and planetary scales. Our results reveal that the global oilseed trade network has become increasingly complex and efficient over the past decade. However, trade volume remains highly concentrated among a few key nations (e.g., the USA, China, and Canada). Structurally, the network has shifted from large, centralized clusters toward a multi-polar reorganization, indicating a dynamic restructuring of supply chain relationships that balances efficiency with emerging risks. Crucially, despite structural risks in the supply chain, China has leveraged massive virtual land imports to stabilize its domestic cultivated land pressure index at a low level (0.13–0.16). This trade mechanism functions as a critical "land-sparing" strategy at the global scale: the total global land savings generated by China's imports steadily increased from 116.4 Mha to 193.1 Mha during the study period. This study highlights the dual role of China in alleviating domestic land pressure while reshaping global resource distribution. While global trade offers resource efficiency, the reliance on concentrated sources poses potential security risks. Future efforts should focus on building resilient supply chains and strengthening regional collaboration to balance national food security with global sustainable sustainability goals. This study demonstrates how integrated modelling approaches linking global trade networks to local land systems can bridge spatial scales, offering new insights for sustainable land management and resilient agroecosystem strategies.