Elucidate the complex drivers of significant greening on the Loess Plateau from 2000 to 2020

Greening and its drivers in the Loess Plateau of China have been extensively studied, but attributional explorations regarding vegetation restoration in different climatic zones remain unclear. This study quantitatively evaluated greening on the Loess Plateau based on Fraction Vegetation Cover (FVC) calculated by MOD13Q1 dataset, compared FVC in different climatic zones, and explored the relationship between greening and precipitation, evaporation, soil water content (SWC), surface water bodies, and human activities. The study found that FVC on the Loess Plateau increased significantly at a rate of 0.538% yr-1 from 2000 to 2020, resulting in 94% greening. The greening rate was higher in the middle temperate zones (0.557% yr-1) than in the southern temperate zones (0.532% yr-1), but its average FVC was lower. This suggests that the greening rate (0.551% yr-1) is higher within 5 km of water bodies. Cropland (15.26%), grassland (13.66%) and trees (12.57%) had higher FVC increment than other types, while the six-fold increase in urban area is a significant impediment to greening. Additionally, there is a significant positive correlation with FVC when the urban economy exceeds 100 billion. The interaction of natural factors and human activities made the greatest contribution to greening, as calculated by the GeoDetector. It is hypothesized that there is significant potential for greening in the middle temperate zones. However, large-scale tree planting may not have a catalytic effect and could even be counterproductive. To achieve sustainable greening of the Loess Plateau in the future, shrubs and artificial water storage facilities may be key.