How does rapid urban construction land expansion affect the spatial inequalities of ecosystem health in China? Evidence from the country, economic regions and urban agglomerations

Identifying the adaptation mechanisms between urban construction land expansion (UCE) and ecosystem health (EHI) is a crucial aspect of sustainable management. However, there is still progress room for existing studies in distinguishing the impact mechanisms of UCE on the EHI of China's cities, different economic subregions and urban agglomerations. These gaps hinder the development of differentiated supportive frameworks for urban land management policies and ecosystem restoration initiatives across various scales in China. This study integrated multivariate satellite remote sensing data to monitor the heterogeneous evolution patterns of EHI and UCE in Chinese cities, economic subregions and urban agglomerations. A set of spatial measure models are utilized to distinguish the variability impact of UCE on China's EHI from a multi-dimensional perspective, including global and local, whole-area and sub-area, and direct and indirect influences. The results indicate that as UCE continues to grow, EHI steadily declined, reaching 0.512 with an average annual decrease of 1.507% from 2000 to 2020. A diminishing cluster pattern of EHI was observed, primarily concentrated in urban agglomerations such as BTH, GBA, and YRD. UCE exhibited a significant negative spatial dependence on EHI, and both global and local perspectives, UCE had a gradually weakening negative effect on the EHI of Chinese cities and economic subregions. However, the impacts of UCE on EHI in mature urban agglomerations (e.g., GBA, BTH, and YRD) were dominated by spatial spillovers, whereas growing urban agglomerations (e.g., MRYRU and CCU) were more affected by direct shocks from UCE. Our investigation informs site-specific ecologically sustainable management strategies in China based on cross-scale analyses, providing new perspectives into establishing cooperative mechanisms for cross-regional ecological management while emphasizing ecological risks management under the integration of urban agglomerations.