[Changes and Driving Factors of Ecosystem Services Supply and Demand in the Yellow River Basin]

Ecosystem services are closely linked to human sustainable development. Studying the supply-demand characteristics of ecosystem services in the research area and identifying their main driving factors are crucial prerequisites for effectively allocating ecological resources and ensuring regional ecological security. The InVEST model was employed to analyze the spatiotemporal evolution and supply-demand matching of water conservation， carbon sequestration and oxygen release， and habitat quality services in the Yellow River Basin from 2001 to 2021. Additionally， a geodetector model based on optimal parameters was used for driving factor analysis. The results indicate： ① Compared to 2001， the supply of water conservation， carbon sequestration and oxygen release， and habitat quality services increased in 2021. Spatially， carbon sequestration and oxygen release services exhibited similar distributions， while water conservation services showed irregular distribution patterns influenced by factors like precipitation and evapotranspiration. ② The spatial distribution of demand for ecosystem services was generally consistent： higher demand in the middle and lower reaches of the basin and lower demand in the upstream river sources， with a fluctuating increasing trend. ③ At the grid scale， the spatial distribution of water conservation， carbon sequestration and oxygen release， and habitat quality services showed characteristics of uneven supply-demand relationships and significant regional differences. At the provincial scale， the supply-demand relationship for water conservation and habitat quality services was relatively balanced overall， with supply generally exceeding demand. However， the supply-demand index for carbon sequestration services showed a continuous declining trend， highlighting prominent supply-demand contradictions. ④ The supply side of ecosystem services was heavily influenced by natural factors， while the demand side was primarily affected by human activities and socio-economic development. Increasing population density and GDP density contributed to the demand for ecosystem services， thereby inhibiting the balance between supply and demand， which is a key influencing factor for ecosystem service supply-demand ratios. The research findings can provide a reference basis for establishing ecological compensation mechanisms in the Yellow River Basin.