Spatiotemporal Characteristics of Typical Ecosystem Services and Their Spatial Responses to Driving Factors in Ecologically Fragile Areas in Upper Yellow River, China

The identification of dominant driving factors for different ecosystem services (ESs) is crucial for ecological conservation and sustainable development. However, the spatial heterogeneity of the dominant driving factors affecting various ESs has not been adequately elucidated, particularly in ecologically fragile regions. This study employed the integrated valuation of ESs and trade-offs (InVEST) model to evaluate four ESs, namely, water yield (WY), soil conservation (SC), habitat quality (HQ), and carbon storage (CS), and then to identify the dominant driving factors of spatiotemporal differentiation of ES and further to characterize the spatial heterogeneity characteristics of the dominant driving factors in the eco-fragile areas of the upper Yellow River, China from 2000 to 2020. The results demonstrated that WY exhibited northeast-high and northwest-low patterns in the upper Yellow River region, while high values of SC and CS were distributed in central forested areas and a high value of HQ was distributed in vast grassland areas. The CS, WY, and SC exhibited decreasing trends over time. The most critical factors affecting WY, SC, HQ, and CS were the actual evapotranspiration, precipitation, slope, and normalized difference vegetation index, respectively. In addition, the effects of different factors on various ESs exhibited spatial heterogeneity. These results could provide spatial decision support for eco-protection and rehabilitation in ecologically fragile areas.