Quantitatively analyzing the driving factors of vegetation change in China: Climate change and human activities

Understanding the impact of climate change and human activities on vegetation dynamics is crucial for ecosystem management. Employing the Residual Trend method and integrating Normalized Difference Vegetation Index (NDVI) data with land use/cover, this study assesses the impacts of climate change and human activities on vegetation dynamics across China from 2000 to 2018. The findings indicate a consistent upward trend of China's Growing Season NDVI (GSN), averaging a change rate of 0.0032/yr. Human activities are the primary drivers of this change, contributing 82.47% to GSN in China, while climate change accounts for 17.53%. The effect of human activities on vegetation dynamics showed considerable variation across different river basins, with the Huaihe River Basin experiencing the highest human impact (93.53%) and the Continental Basin the lowest (76.27%). Conversely, the Continental Basin experienced the greatest impact from climate change (23.73%), compared to the minimal influence in the Huaihe River Basin (6.47%). The study results offer contribution rates for each type of changed and unchanged land use, with persistent forestland, persistent grassland, persistent cropland, and grassland to forest conversion contributing 28.65%, 22.09%, 13.76%, and 4.61%, respectively. Persistent forestland emerges as the most efficacious land use type for facilitating vegetation restoration. Within the persistent forestlands of the Yangtze, Pearl, and Southeast River Basins, human activities accounted for 26.99%, 42.18%, and 43.50% of the vegetation alterations, respectively. These findings provide a scientific basis for formulating effective ecosystem management and protection strategies.