Analysis of the Trade-offs/Synergies and DrivingForces of Ecosystem Services in the Yellow RiverBasin from 2000 to 2020

The Yellow River Basin (YRB) has been central to China's strategy for achieving high-quality development by balancing ecological, economic, and social growth while ensuring environmental protection and restoration.Despite macro-level policy successes, detailed micro-level studies on the trade-offs, synergies, and driving forces of ecosystem services (ES) in this region remain limited.This study addresses this gap by examining the spatiotemporal dynamics, trade-offs, synergies, and driving forces of six key ES -soil conservation, food supply, habitat quality, water conservation, climate regulation, and wind and sand control -in the YRB from 2000 to 2020.Utilizing ecological models like InVEST and diverse data sources, including MODIS satellite imagery and climate databases, we quantified these ES and used Spearman's correlation coefficients along with spatialtemporal regression models to assess trade-offs and synergies.The Random Forest model and multiple linear regression were employed to identify ES drivers in both temporal and spatial dimensions.Results indicate significant spatial heterogeneity in ES within the YRB over the past two decades, with a general upward trend in service provision.The range of high and medium-value areas in each ecosystem gradually expanded while the range of low-value areas gradually shrank.Temporally, ES exhibited fluctuating but generally increasing trends.Among them, grain yield, soil conservation, and water conservation increased by 70.3%, 74.1%, and 17.7% on average.The synergistic effect between water resources protection and climate regulation is the strongest, with an average correlation coefficient of 0.39 in the past 20 years, while the trade-off between windbreaks and climate regulation caused by land use change is particularly prominent, with an average correlation coefficient of -0.3712.The analysis identified natural factors (NDVI, AET) and human activities (population density) as primary ES drivers.NDVI has an important impact on ecosystem services, and the contribution rate of NDVI to HA and HM is more than 40%.POP is dominant in HA and SR, especially in FP, with a driving degree greater than 40%.This research provides vital insights into YRB ES dynamics, Pol.J. Environ.Stud.Vol.XX, No. X (XXXX), 1-13 offering a scientific foundation for policies aimed at ecological sustainability and high-quality regional development.