Evidence of vegetation greening benefitting from the afforestation initiatives in China

Abstract

Recent research shows that China is experiencing significant greening, with afforestation initiatives being the main cause. Quantitative calculation of vegetation change influencing factors and evaluation of the contribution of afforestation to vegetation greening in China are critical to coping with climate change and improving the implementation and efficacy of forestry projects. We investigated the temporal and spatial dynamics of the Normalized Difference Vegetation Index (NDVI) from 1982 to 2020, and quantified the contribution of afforestation initiatives, a typical human activity, to the dynamic changes of vegetation. The results showed that NDVI in China has primarily increased in the last 39 years. 57% of the pixels increased, 27% were stable and unchanged, and 16% decreased. Climate change was responsible for 72.34% of vegetation restoration, while human activities were responsible for 27.36% of vegetation restoration, according to residual analysis. In the future, only 14% of the regions showed continuous growth of the NDVI, while the remaining regions showed obvious antipersistence (59% will go from increasing to decreasing, and 22% will go from decreasing to increasing). The contribution of climate factors to vegetation change will decrease in the future, and human activities will become more complex. Except for Huaihe River and Taihu Lake (SPHRTL), other forestry projects showed an increasing trend of NDVI after the implementation of ecological engineering. However, due to differences in climate conditions and ecological engineering implementation, there are differences in the benefits of forestry projects. Some forestry project areas still have obvious vegetation degradation, and appropriate forestry management is necessary. This work provides a quantitative analysis of vegetation change and its driving factors in China, which will help to cope with future climate change and provide a reference for the implementation and management of ecological projects.

Keywords

• Vegetation greening
• climate change
• human activities
• afforestation initiatives
• China