The reducing effect of global greening on vegetation recovery time is disappearing

With the ongoing global vegetation greening and the increasing frequency of drought events, the likelihood of drought disturbances to vegetation is rising. The time it takes for vegetation to return to their normal state after a drought is known as recovery time. Investigating how vegetation greening influences drought recovery time is vital for the sustainable development of terrestrial ecosystems. In this study, we assessed global vegetation changes and recovery time over the past forty years using vegetation data. We employed a machine learning model to analyze the relationships between influencing factors and recovery time, while also determining the spatial distribution of the main influencing factors. The results indicate that approximately 40% of global regions exhibit a significant greening trend, with over 90% of drought recovery events occurring between January and April. We found vegetation greening enhances recovery resilience and reduces recovery time. Soil moisture, vapor pressure deficit (VPD), and temperature during recovery can hinder vegetation regrowth when they are at extreme values. In some areas, prolonged greening may lead to longer recovery time following droughts. These findings suggest that while greening typically decreases recovery time, sustained greening may extend recovery duration once a certain regional threshold is reached. Therefore, it is crucial to consider the trade-offs between greening and vegetation resilience in the context of ongoing global greening.