Asymmetric Responses of Ecosystem Health to Urbanization in a Typical Karst City: Spatiotemporal Patterns and Driving Mechanisms in Guilin, China

ABSTRACT

Urban expansion can substantially reshape ecosystem structure and functioning, especially in ecologically fragile Karst landscapes. Clarifying how ecosystem health (EH) responds to urbanization and identifying the factors that drive spatial variation in EH are important for regional sustainability. In this study, the Vigor–Organization–Resilience–Services (VORS) framework was used to construct an ecosystem health index (EHI), and a multidimensional urbanization level (UL) index was developed to examine the spatiotemporal patterns of EH and urbanization in Guilin from 1990 to 2020. Bivariate Moran's I , the geographical detector model, and geographically weighted regression (GWR) were further applied to reveal the spatial association and driving mechanisms of EHI. The results showed that: (1) EHI in Guilin generally improved from 1990 to 2020, whereas UL expanded rapidly along valleys and transportation corridors under Karst topographic constraints; (2) EHI and UL showed a significant negative spatial association, with areas of high UL and low EHI mainly concentrated in the central urban core and expanding urban fringes; (3) UL, normalized difference vegetation index, potential evapotranspiration, and elevation were the dominant factors affecting EHI, with UL showing the strongest explanatory power; and (4) the ecological effect of urbanization was spatially asymmetric, characterized by ecological saturation in the central built‐up area and high ecological sensitivity in the urban expansion frontier. These findings provide spatially explicit evidence for differentiated ecological governance in fragile Karst cities.