Impacts of urbanisation on vegetation dynamics in Chinese cities

Abstract

Urbanisation is a global phenomenon that dramatically impacts ecosystems and their services. In recent years, urbanisation in China increased substantially. To improve the urban environment, the Chinese government has implemented several programs to green the cities' central areas and limit forest and grasslands in expanding areas. However, more information is needed about the trend and the factors affecting vegetation status in urban centres and expanding areas. Here we studied the vegetation in these areas in 3345 cities in China using 30 m spatial resolution Annual Net Primary Production (NPP) Change (ANC) and NPP Change Rate (ANCR) in 2000 and 2020. The results showed that most Chinese cities' central areas have a greening trend. However, vegetation cover decreases in expansion areas, mainly in southern cities. The opposite is observed in some urban areas in the country's North. This is mostly attributed to the highest urbanisation trends observed in the South than in the North. The most important factors that affected the ANC trend were mean temperature/precipitation, expansion area, and CO2 changes. ANCR was mainly affected by mean temperature/precipitation. Political decisions such as increasing the greening areas in city centres in China also affected the increase of vegetation in urban cores. In some cities located in the North, the investment in green infrastructure in expansion areas may have also contributed to increased vegetation. The results are important for managers to improve cities' livability, especially in the South of China, where the degradation of the ecosystems is high in expansion areas.