Spatiotemporal Characteristics of Ecosystem Services and the Threshold Effects of Driving Factors in the Beijing-Tianjin-Hebei Region

Analyzing the driving mechanisms of ecosystem services (ESs) through threshold analysis is crucial for targeted ecological optimization. While ES drivers have been examined in previous research, limited attention has been devoted to nonlinear responses and threshold extraction. Adjusting optimal thresholds for key drivers to enhance ESs remains challenging. Based on assessments of four types of ESs and total ecosystem service (TES), twelve natural and anthropogenic drivers were analyzed through segmented linear regression to identify their interactions with TES from 2000 to 2020. The results identified significant spatial differences in the four ESs: food production (FP) concentrated in plains and valleys; water yield (WY) was high in mountainous-coastal zones; soil conservation (SC) was high in mountains but low across plateaus and plains; carbon sequestration and oxygen production (CSOP) was high in northern BTH yet low in southeastern plains and the Bashang Plateau, together with the maximum TES increasing from 1.39 in 2000 to 1.66 in 2010, then rising slightly to 1.67 in 2020. Geographically weighted regression coefficients reveal the spatial heterogeneity of drivers’ impacts on TES and support differentiated driver-targeted regulation. Key thresholds in natural drivers, including elevation (890 m), slope (17.18°), temperature (7.90 °C), and distance from water bodies (2.40 km), exhibited significant threshold effects. All anthropogenic variables showed negative correlations with ESs, with population density (1695.00 people/km²) and gross domestic product (GDP, 185 × 10⁶ CNY) exhibiting significant threshold effects. According to the thresholds, potential high-ES areas were identified, covering 5.94% of the region and predominantly located in its western and northern parts. With the 20% downward and upward threshold adjustment scenarios, these areas exhibited a 91.63% increase and a 76.26% decrease, respectively, which highlights their high sensitivity to threshold variations. The slope, temperature, and distance from water bodies had the greatest impact on ESs. Our findings highlight the impacts of threshold adjustments on ESs and underscore the significance of target-specific threshold regulation for ecological management and territorial spatial planning.