Pathways of driving mechanisms for ecosystem services in the Yellow River Basin: insights from scale prioritization...

Comprehending the intricate interactions between ecosystem services (ESs) and their driving factors at various spatial scales is crucial for enhancing ecosystem management and developing tailored zoning strategies. However, research on cross-scale interactions and integrated multi-method analyses of ESs dynamics in the Yellow River Basin (YRB) remains limited, impeding the precise implementation of ecological conservation policies. This study examines the evolutionary characteristics and interactions of ESs across different spatiotemporal scales in the YRB. By integrating multiple analytical methods, including random forest (RF), partial dependence analysis (PDA), geographically weighted regression (GWR), and partial least squares structural equation modeling (PLS-SEM), we identify key driving factors and their spatial heterogeneity, and elucidate their direct and indirect causal pathways. The results indicate that: (1) Temporally, water yield, food production, and soil conservation have significantly increased, whereas carbon sequestration and habitat quality have slightly declined; spatially, each ecosystem service exhibits distinct gradient differentiation. (2) Interactions among ESs within the basin are predominantly synergistic and have intensified over time. Correlation strength and statistical significance at the county scale are higher than those at other spatial scales. (3) Between 2000 and 2020, nonlinear responses and threshold effects were widespread between ESs and their driving factors. (4) Topography, climate, and vegetation exert significant positive direct effects on ESs, with topography having the strongest influence, while human activities exhibit a weaker direct inhibitory effect. This study underscores the importance of identifying the spatial heterogeneity of ESs and their underlying driving mechanisms to inform ecological management decisions, and provides a scientific foundation and practical guidance for multi-scale ecosystem governance.