Segmented optimization for river ecological corridor width based on ecosystem services: a case study of the North Canal River, China.

Adapting to climate change requires a better understanding of how the spatial configuration of river ecological corridors influences both ecological connectivity and ecosystem service delivery. Corridor width is a critical factor in corridor planning, yet uniform design approaches often overlook the strong spatial heterogeneity between urban and rural river segments. In this study, we investigated the North Canal River in Beijing, quantifying the effects of corridor width on ecosystem service value through integration land use data (1990–2020), landscape pattern metrics, and segmented regression analysis. The results revealed pronounced contrasts in land–use trajectories between urban and rural corridors. Urban cropland declined by more than 70%, while built–up land expanded substantially before partially retreating following large–scale ecological restoration after 2015. Rural corridors experienced more moderate cropland loss and consistently maintained higher landscape aggregation and lower fragmentation. Increasing corridor width enhanced spatial connectivity and landscape stability, particularly in rural segments. Ecosystem service value exhibited a clear non–linear response to corridor width. Urban river corridors were increasingly dominated by cultural services, whereas rural corridors retained robust regulation and supporting services. Breakpoint models identified service–based width thresholds at approximately 126 m for urban and 311 m for rural corridors, respectively. These findings underscore the importance of context–specific corridor design that accounts for spatial heterogeneity in ecosystem service responses and provide quantitative support for adaptive river corridor planning in rapidly urbanizing regions.