Linkages between digital economy and ecosystem services: Revealing the spatiotemporal relationship based on U-shaped effect

This study employs geographically and temporally weighted regression and spatial Durbin models to investigate the impact of digital economy index (DEI) on ecosystem service value (ESV). Estimates of DEI are obtained from night-time light data, and ESV is assessed by the equivalent factor method. The findings indicate significant spatial agglomeration of both DEI and ESV in China. Overall, the impact of DEI on ESV exhibits a U-shaped effect: initially restrained, then promoted. Moreover, the analysis detects spatiotemporal heterogeneity in the DEI-ESV interaction. Spatially, higher DEI positively impacts lower ESV in eastern China, while lower DEI negatively impacts higher ESV in western China. Temporally, most cities in eastern China, unlike those in western China, surpassed the U-shaped curve's inflection point during the study period. Furthermore, the number of cities exceeding the inflection point has increased, amplifying the dual positive and negative impacts of DEI on ESV over time. By revealing the multi-staged and geographically diverse impact of DEI on ESV, this study helps to address the environmental sustainability challenges posed by the rapid advancement of digital technologies.