The combination of drought and heat affects forest ecosystems by deteriorating the health of trees, which can lead to large‐scale die‐offs with consequences on biodiversity, the carbon cycle, and wood production. It is thus crucial to understand how drought events affect tree health and which factors determine forest susceptibility and resilience. We analyze the response of Central European forests to the 2018 summer drought with 10 × 10 m satellite observations. By associating time‐series statistics of the Normalized Difference Vegetation Index (NDVI) with visually classified observations of early wilting, we show that the drought led to early leaf‐shedding across 21,500 ± 2,800 km², in particular in central and eastern Germany and in the Czech Republic. High temperatures and low precipitation, especially in August, mostly explained these large‐scale patterns, with small‐ to medium‐sized trees, steep slopes, and shallow soils being important regional risk factors. Early wilting revealed a lasting impact on forest productivity, with affected trees showing reduced greenness in the following spring. Our approach reliably detects early wilting at the resolution of large individual crowns and links it to key environmental drivers. It provides a sound basis to monitor and forecast early‐wilting responses that may follow the droughts of the coming decades.

中文翻译：

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中欧森林对2018年极端干旱的大规模早期枯萎反应

干旱和高温的结合使树木的健康状况恶化，从而影响森林生态系统，从而导致大规模的死亡，从而影响生物多样性，碳循环和木材生产。因此，至关重要的是要了解干旱事件如何影响树木健康以及哪些因素决定了森林的敏感性和复原力。我们使用10×10 m卫星观测数据分析了中欧森林对2018年夏季干旱的响应。通过将归一化植被指数（NDVI）的时间序列统计数据与早期萎缩的视觉分类观察结果进行关联，我们表明干旱导致了21,500±2,800 km ^2的早期落叶，尤其是在德国中部和东部以及捷克共和国。高温和低降水，尤其是在八月，主要解释了这些大范围的格局，中小型树木，陡峭的斜坡和浅层土壤是重要的区域危险因素。早期的枯萎揭示了对森林生产力的持久影响，受影响的树木在次年春天显示出降低的绿色度。我们的方法能够可靠地检测出早期的枯萎，且分辨率大，可以将其与重要的环境驱动因素联系起来。它为监测和预测可能在未来几十年的干旱之后的早期枯萎反应提供了良好的基础。