Vegetation dynamics of the north Chinese grassland in the past 20 years

Grasslands represent an important green ecological barrier in the terrestrial environment. The north Chinese grassland accounts for 40.72% of the total grassland area in China. Using satellite data on vegetation index, this study analyzed vegetation dynamics in the north Chinese grassland over the past 20 years, from 2000 to 2019. It was found that from 2000 to 2019, the vegetation index of China’s northern grassland showed a significant growth trend (P < 0.01), with an annual increase of 0.0029 in normalized difference vegetation index and a stable growth rate of 24% over this 20-year period. From 2000 to 2019, the northern grassland showed overall vegetation restoration despite partial vegetation degradation in some areas; areas where vegetation was restored accounted for 52.22% of the grassland, while areas where it was degraded accounted for 0.86%. The effects of this restoration were most obvious at lower latitudes and in humid and semi-humid regions. Areas with no obvious change were mainly distributed in higher latitudes and arid regions, where natural conditions are very poor and vegetation restoration is more difficult. More attention should be given to the long-term and continuous restoration of the grassland.