How does urbanization impact the supply-demand relationship of agroecosystem services? Insights from farmland loss in the Huaihe River Basin, China

China's urbanization has gradually become the dominant factor in farmland loss, but it remains unclear how urbanization impacts the supply-demand relationship of agroecosystem services at different rates of farmland loss, which in turn poses new challenges to the ecological security of farmland. Taking the Huaihe River Basin as a case, this paper analyzes farmland loss from 2000 to 2020, as well as changes in the supply-demand rela-tionship of four types of agroecosystem services: food production, socio-economic security, carbon sequestration, and soil conservation, revealing the driving mechanisms of urbanization on the supply-demand relationship of agroecosystem services in sub-regions with different rates of farmland loss. The results show that: (1) A total of 13588.11 km2 of farmland was converted to construction land from 2000 to 2020, accounting for 75.62 % of the total amount of farmland converted to different land types, and 95.57 % of the total amount of farmland con-verted to construction land. (2) There was a surplus supply of grain production services and socio-economic security services, while there was a deficit in the supply of carbon sequestration services, and a balance in the supply-demand of soil conservation services. (3) The matching degree of supply-demand for agroecosystem services was lower in the Rapid Loss Area compared to the Medium Loss Area and Slow Loss Area. (4) Urban-ization was divided into population, economic, and spatial urbanization. The supply-demand relationships of agroecosystem services were impacted greatly by spatial urbanization in the Rapid Loss Area and by economic urbanization in the Medium Loss Area and Slow Loss Area.