Urbanization weakens vegetation resilience in the Pearl River Delta, China

Rapid urbanization has introduced increasingly complex social-ecological processes, intensifying the impacts on vegetation growth. Assessing urban vegetation resilience is critical to understanding urban vegetation growth. However, the current understanding of vegetation resilience in highly urbanized areas, especially regarding the influence of human activities, remains limited, constraining efforts toward sustainable urban vegetation management. In this study, we identified the spatiotemporal heterogeneity of urban vegetation resilience in the Pearl River Delta (PRD) using the lag-one autocorrelation coefficient (AC1) of the enhanced vegetation index (EVI) derived from Landsat imagery. Referring to the general conceptual framework for quantifying the impacts of urbanization on vegetation growth, we assessed the impacts of urbanization on vegetation resilience in the PRD urban agglomeration from 1998 to 2022. Results revealed that 21% of the urban area experienced one to five vegetation loss events, primarily lasting 1-2 years. Although vegetation growth was enhanced along the urbanization intensity gradient, a significant (p < 0.05) downward trend in vegetation resilience was observed, indicating that urbanization restricted the stability and sustainability of urban vegetation. By distinguishing between direct and indirect impacts, we found that the indirect impacts of urbanization on vegetation resilience gradually outweighed the direct impacts over time. Our findings further demonstrate that while intensive management can promote regreening in urban settings, maintaining the prevalent stability of urban vegetation remains challenging. These findings contribute to a better understanding of the human impact on vegetation resilience and offer significant implications for seeking directions to improve urban vegetation resilience.