Ecosystem drought recovery and influencing factors in temperate China and the Qinghai-Tibet alpine region

The increasing frequency and severity of droughts are expected to pose serious threats to vegetation growth in temperate China and the Qinghai-Tibet alpine region. Although drought recovery time represents a crucial aspect of vegetation recovery, the relationship between recovery time and resilience remains insufficiently understood. This study employed remote sensing vegetation indices and the standardized precipitation evapotranspiration index (SPEI) to analyze vegetation drought recovery time and resilience in temperate China and the Qinghai-Tibet alpine region. Furthermore, the study applied an extreme gradient boosting (XGBoost) model integrated with SHapley Additive exPlanations (SHAP) framework to identify key determinants of vegetation recovery. The results showed that vegetation in approximately 70 % of the study area recovered to normal conditions within 6 months after drought. Recovery time was longer in arid and humid regions, while it was 0.5–1 month shorter in semi-humid and semi-arid regions. Recovery time was strongly influenced by the climatic conditions during and before the drought recovery period. Drought resilience was markedly lower in arid regions relative to semi-arid, semi-humid, and humid regions. Elevation, drought intensity, and vegetation conditions were identified as key drivers of resilience. Additionally, droughts occurring in the early growing season required a longer recovery time but exhibited generally higher resilience than those occurring in the late growing season. This study also highlights regions that are facing severe drought recovery challenges. These results provide important insights for understanding ecosystem drought recovery and offer scientific support for drought management strategies in temperate China and the Qinghai-Tibet alpine region.