Quantifying global vegetation recovery speed in response to extreme drought using multi-dimensional spatiotemporal data

Elucidating the spatiotemporal patterns of global vegetation post-drought recovery and their coupling mechanisms with climatic factors is critical for advancing our understanding of terrestrial ecosystem stability and enhancing the accuracy of global carbon sink modeling. However, significant controversies persist regarding the primary determinants influencing vegetation recovery trajectories following drought events and their underlying regulatory mechanisms. This study integrates multi-source vegetation indices (LAI, NDVI, and SIF) with environmental variables (SM, TMP, PRE, VPD) to systematically quantify the spatiotemporal characteristics of post-drought vegetation recovery during extreme events from 2018 to 2021, identifying key regulatory mechanisms across different climatic zones. The results indicate that: (1) the global average vegetation recovery time is 3.25 months, yet prolonged recovery periods are observed in regions like the southwestern United States and southern mid-latitudes; (2) soil moisture and temperature are the dominant drivers of recovery, affecting 72% and 68% of global vegetated areas, respectively; (3) temperature predominantly drives recovery in boreal and southern mid-/low-latitude zones, while soil moisture and VPD dominate in northern mid- and low-latitudes. This study establishes a methodological framework for quantifying vegetation restoration time and identifying its primary climate drivers, aiding understanding of climate change impacts on ecosystems and ecological management strategies.