China's Holocene crops did not spread as one farming frontier: millet, rice and wheat/barley each followed their own spatial opportunity structure
Holocene agriculture in China did not expand as one uniform farming frontier. Combining archaeological crop records with palaeoclimate, terrain and river-network data, a crop-specific dynamic non-local diffusion model estimates the relative probability of new crop records during 6000–2000 BP. Millet records were most associated with same-crop persistence and non-local diffusion, rice records most with humid-lowland environmental filtering, and wheat/barley records with corridor-like accessibility along the Hexi Corridor–Central Plains belts and higher frontier mobility.