近日，荷兰乌得勒支大学Arie Staal团队揭示了森林砍伐引起的干燥降低了亚马逊的气候阈值。相关论文于2026年5月6日发表在《自然》杂志上。

人类正通过全球变暖和土地利用变化对亚马孙森林系统施加前所未有的压力。由于亚马孙森林可能发生自我强化的转变，这些压力可能导致亚马孙生态系统大范围的全系统变化。

研究组应用动态系统模型，评估了在不同共享社会经济路径下，亚马孙生物群落向退化生态系统演变的局部及远程级联过渡风险。针对这些排放情景，研究组利用已有的大气水汽追踪模型，构建了水汽在亚马孙流域内的大气输送过程。在不考虑森林砍伐的情况下，他们发现全球变暖的关键阈值为3.7–4.0 °C，一旦超过该阈值，多达三分之一的亚马孙森林将面临失去稳定性的风险。然而，当考虑森林砍伐时，在全球变暖较低阈值范围（1.5–1.9 °C）与森林砍伐率22–28%的共同作用下，研究组发现亚马孙森林将发生近乎全系统的转变（62−77%的区域）。

大多数模拟的转变是由干旱强度增加引发的空间连锁效应造成的，这种效应在数百至数千公里的尺度上产生长距离、自我传播的级联反应。总体而言，该结果强化了将全球变暖水平控制在1.5 °C以下、停止森林砍伐以及对退化森林进行生态恢复的必要性，以避免亚马孙森林系统面临高过渡风险。

附：英文原文

Title: Deforestation-induced drying lowers Amazon climate threshold

Author: Wunderling, Nico, Sakschewski, Boris, Rockstrm, Johan, Flores, Bernardo M., Hirota, Marina, Staal, Arie

Issue&Volume: 2026-05-06

Abstract: Humanity is putting unprecedented pressures on the Amazon forest system through global warming and land use changes1,2. As the Amazon forest may undergo self-reinforcing transitions, these pressures could lead to system-wide changes across major parts of Amazonian ecosystems1,2,3,4. Here we apply a dynamical systems model to assess the local and far-reaching cascading transition risks towards degraded ecosystems in the Amazon biome under different Shared Socioeconomic Pathways. For these emission scenarios, we constructed how moisture is transported through the atmosphere within the Amazon basin using an established atmospheric moisture-tracking model5. Without accounting for deforestation, we find a critical global warming threshold of 3.7–4.0°C, beyond which up to a third of the Amazon forest risks losing stability. However, when considering deforestation, we find a near system-wide transition of the Amazon forest (6277% of the area) under the combination of a lower threshold range of global warming of 1.5–1.9°C and deforestation of 22–28%. The large majority of the simulated transitions is caused by spatial knock-on effects from increasing drought intensities, leading to long-ranging and self-propelling cascades on scales of hundreds to thousands of kilometres. Overall, our results reinforce the need to keep global warming levels below 1.5°C and halt deforestation, as well as ecologically restore degraded forests to avoid high transition risks across the Amazon forest system.

DOI: 10.1038/s41586-026-10456-0

Source: https://www.nature.com/articles/s41586-026-10456-0