瑞士苏黎世联邦理工学院Lei Gu团队近日揭示极端高温加剧了突发性干旱对全球生态系统的影响。该研究于2025年6月2日发表在《自然—地球科学》杂志上。
以快速发生为特征的突发干旱会造成毁灭性的社会经济和农业损失。在此类事件中，土壤水分消耗不仅是由降水短缺造成的，也是由极端高温引起的大气水分需求增加造成的。然而，极端高温在塑造突发干旱演变及其生态影响方面的作用仍然不确定。
研究组通过分析1950年至2022年的全球再分析数据来研究所涉及的过程。 结果发现，当闪旱伴随着极端高温时，它们的严重程度比没有极端高温的闪旱高6.7-90.8%，恢复时间长8.3-114.3%。突发干旱期间极端高温的存在加速了高纬度地区的土壤水分下降，潮湿的土壤和增强的辐射促进了蒸散。相比之下，由于蒸散量的限制，它减缓了亚热带过渡气候带的绝对发病速度。
该机器学习方法进一步揭示，高温突发干旱导致生态系统生产力急剧下降，特别是在农田中，从而威胁到全球粮食安全。这些发现强调了在变暖的未来，迫切需要加强基础设施和生态系统对高温突发干旱的抵御能力。
附：英文原文
Title: Flash drought impacts on global ecosystems amplified by extreme heat
Author: Gu, Lei, Schumacher, Dominik L., Fischer, Erich M., Slater, Louise J., Yin, Jiabo, Sippel, Sebastian, Chen, Jie, Liu, Pan, Knutti, Reto
Issue&Volume: 2025-06-02
Abstract: Flash droughts—characterized by their rapid onset—can cause devastating socioeconomic and agricultural damage. During such events, soil moisture depletion is driven not only by precipitation shortages but also by the elevated atmospheric moisture demand arising due to extreme heat. However, the role of extreme heat in shaping the evolution of flash droughts and their ecological impacts remains uncertain. Here we investigate the processes involved by analysing global reanalysis data from 1950 to 2022. We find that, when flash droughts are accompanied by extreme heat, they exhibit 6.7–90.8% higher severity and 8.3–114.3% longer recovery time than flash droughts without extreme heat. The presence of extreme heat during flash droughts accelerates soil moisture drawdown over high latitudes, where wet soils and enhanced radiation foster evapotranspiration. By contrast, it slows the absolute onset speed in subtropical transitional climate zones owing to evapotranspiration throttling. Our machine learning approach further reveals that hot flash droughts lead to sharper declines in ecosystem productivity, particularly in croplands, thereby threatening global food security. These findings underscore the pressing need for enhanced infrastructure and ecosystem resilience to hot flash droughts in a warming future.
DOI: 10.1038/s41561-025-01719-y
Source: https://www.nature.com/articles/s41561-025-01719-y