Ecosystem services in the Yangtze River Economic Belt: Spatiotemporal characteristics, trade-offs/synergies, and driving factors.

Abstract

Ecosystem services (ES) play a vital role in socioeconomic development. Existing research has primarily focused on single-service assessments and linear relationships, overlooking often neglecting non-linear interactions, threshold effects, and spatial heterogeneity among ES. The Yangtze River Economic Belt (YREB) was analyzed to evaluate water yield (WY), soil conservation (SC), carbon storage (CS), habitat quality (HQ), and total ecosystem services (TES). Methods including constraint lines, geographically weighted regression, and machine learning were applied to systematically identify spatiotemporal evolution patterns, interrelationships, and driving factors of ES. The results indicate that: (1) From 2005 to 2020, ES in the YREB exhibited marked spatiotemporal variability; WY and SC increased over time, whereas CS, HQ, and TES declined. Spatially, SC, CS, and HQ were consistently higher in western and southern regions, while WY followed a southeast-to-northwest decreasing gradient. (2) Relationships between ES revealed distinct dynamics: CS-HQ, WY-CS, and SC-CS were dominated by trade-offs, whereas WY-SC, WY-HQ, and SC-HQ displayed synergies with constraint effects, demonstrating pronounced spatial heterogeneity. (3) Annual precipitation and the Normalized Difference Vegetation Index (NDVI) significantly enhanced their positive driving effects on TES after exceeding their respective critical thresholds. Conversely, the influence of built-up area proportions sharply reversed from an initially positive effect to a strongly negative one once a threshold was crossed. These findings provide a scientific basis for ecological conservation strategies and regional sustainable development, advancing comprehensive assessment and management of ecosystem services.