Climatic constraints on the indirect impacts of urbanization on vegetation growth in China

Understanding the factors and mechanisms that influence the impact of urbanization on vegetation growth is crucial for climate change mitigation and urban greening initiatives. However, the long-term evolution mechanisms of these impacts, particularly in the context of changing climate and water scarcity, are not yet fully understood. In this study, we evaluated the long-term indirect impacts of urbanization on vegetation growth across 2,385 county-level cities in China. We found that the trend of vegetation enhancement induced indirectly by urbanization is less pronounced in arid zones compared to humid zones. In addition to the vegetation removal caused by urbanization, the expansion of urban spaces can compensate for vegetation loss by fostering growth, surpassing the effects of economic and population growth. However, in arid zones, the positive impacts and regulation amplitudes of urban spatial expansion on vegetation growth are constrained due to high urban water scarcity. These insights may contribute to a more accurate assessment of carbon gains or losses in urbanized vegetation.