Assessing the impacts of rural depopulation and urbanization on vegetation cover: Based on land use and nighttime light data in China, 2000-2020

Since the 21st century, China has shown dramatic rural depopulation and rapid urbanization, and surface vegetation has been affected by this urban-rural development pattern. Using remote sensing and population data from 2000 to 2020, we investigated the spatial and temporal evolution of terrestrial vegetation under the coexistence of "rural population loss and urbanization". We also analyzed the relationship between rural population loss, urbanization and the area covered by four types of vegetation (forest, grassland, shrubs and cropland). We found that from 2000 to 2020, the area covered by forests is increasing, and the area covered by shrubs, grasslands, and cropland is decreasing. Spatially, the results of the Moran index prove that the surface vegetation is characterized by spatial autocorrelation. Grasslands are predominantly located on the western side of the Hu line, and forests, shrubs, and croplands are predominantly located on the eastern side of the Hu line. Rural depopulation contributes to the growth of forest and grassland cover, but inhibits the growth of shrub cover. The advance of urbanization reduces the area covered by forests and shrubs, but benefits the growth of grassland cover. As a result of the direct effect, rural depopulation contributes to the reduction of cropland, while urbanization promotes the growth of cropland, and the opposite is true for the spillover effect. This study helps us to better understand the direction of ecological shifts in urban-rural migration patterns.