Supplementary file 1_Scenario-driven optimization of land-use/land-cover conversion pathways to improve ecosystem service performance in the Yellow River Basin.docx

Because NE is a negative attribute, its increase indicates weakened water-purification performance and may reflect intensified land-use pressure or agricultural activity. More diverse LULC configurations were generally accompanied by more synergies among ESs, while trade-offs mainly occurred between HQ and WY, particularly in downstream regions. IESI broadly increased, except in “spatially clustered low-performance” or “spatial mismatch” areas characterized by low-low clusters or low-high outliers of IESI and often located in upstream and midstream regions with cropland expansion.

A moderate conversion of cropland and undeveloped land in LULC-optimization priority areas into a combination of grassland (12.2%–15.7% of the priority-area extent) and forest (4.3%–6.8%) was identified as the preferred conversion pathway. This pathway increased mean IESI within the priority areas by 6.2%–6.4% and basin-wide mean IESI by approximately 0.9%–1.1%. Under this LULC conversion pathway, the modelled socioeconomic-IESI relationships changed differently, with the negative association between population and IESI weakening and gross domestic product (GDP) shifting from a negative to a positive association with IESI, while significant spatial spillover effects indicated interdependence among neighboring cities.

These findings warrant greater consideration of targeted LULC optimization and cross-city interactions in future basin-scale ES management.</p>