Spatiotemporal evolution and trade-off and synergy analysis of ecosystem service factors in the Yellow River water conservation area

To explore the spatiotemporal evolution patterns of ecosystem services in the water conservation area of the Yellow River, the InVEST model was employed to calculate five ecosystem service factors from 2000 to 2020, including carbon storage, soil retention, habitat quality, water yield capacity, and water conservation. The spatiotemporal evolution characteristics of these factors and their trade-offs and synergies were analyzed. The results indicate that from 2000 to 2020, the water yield capacity, water conservation, and soil retention in the Yellow River water conservation area exhibited consistent fluctuations, while habitat quality and carbon storage showed an overall declining trend. There were varying degrees of synergistic correlations between the ecosystem service factors, with the strongest synergies observed between soil retention and water yield capacity, as well as between soil retention and carbon storage. Other factors exhibited moderate or weak synergistic relationships. The five ecosystem service factors were closely related to land use types, and there are significant differences in each factor under different land use types. Synergies dominated between the various ecosystem service factors, with the overall synergistic relationship showing a slight fluctuating upward trend over time. In terms of spatial distribution, the grasslands in the central and southern regions were dominated by high-high synergies, while low-low synergies were primarily found in the grasslands and forests of the northern region. High-low and low-high trade-offs were mainly scattered in cultivated lands and construction lands in the eastern and western regions.