The impacts of urbanization and climate change on urban vegetation dynamics in China

Abstract

Climate change and urbanization are the two major drivers that can alter vegetation growth processes in the urban environment. However, the effects of these two drivers on the continuous vegetation dynamics in the urban environments are not well understood, especially at a high spatial resolution. This study identified the urban fringe zones and explored the spatiotemporal variations of vegetation dynamics (Normalized Difference Vegetation Index) and the mechanisms underlying these variations in the urban core areas and urban fringe zones of China during 2000–2013. The results suggested that from 2000 to 2013, rapid urbanization regions in Yangtze River Delta experienced a high probability of vegetation degradation. However, some rapid urbanization areas in other parts of China did not undergo such sharp vegetation degradation. We demonstrated that about 63 % of the vegetated areas in urban environments showed increasing trends, and the greening trend in the urban core areas was higher than that of urban fringe regions. Furthermore, the relative contributions of climate change, urbanization, and other factors to vegetation variation in the urban area were 33 %, 24 %, and 43 %, respectively. The contribution of urbanization was higher in urban fringe zones than in urban core areas, while the climate change and residual factors were both higher in urban core areas. Our results verified that the urbanization process would not necessarily result in large-scale vegetation degradation. The vegetation in urban environments was mainly determined by climatic variables rather than urbanization. Based on these findings, we propose that the development of fringe areas outside the urban core areas should be avoided as much as possible to effectively mitigate vegetation degradation and the positive influences of urbanization on vegetation growth through effective urban landscape planning should be encouraged.