西北农林科技大学赵杰和岳超教授团队合作取得新进展。他们最新的研究探明了森林火灾规模与火灾后地表变暖之间的联系。这一研究成果于2024年9月25日发表在国际顶尖学术期刊《自然》上。

本研究通过卫星观测发现，在北半球的温带和北方森林中，火灾规模持续放大了夏季每单位燃烧面积长达十年后的地表变暖。随着阔叶树丰度的增加，变暖及其随火灾规模的放大都减弱，这与它们比针叶树更低的火灾脆弱性相一致。

火灾规模增强的变暖可能影响火后林分再生的成功和组成以及永久冻土退化，对未来气候和火灾动态产生以前被忽视的额外反馈效应。研究结果强调，考虑到预计北部森林火灾规模的增加，气候智能型林业应致力于减轻大火的气候风险，可能通过适当增加阔叶树的比例，并避免使用活跃的焦植物。

据介绍，气候变暖导致极端火灾天气普遍增加，使森林火灾持续时间更长，规模更大。近几十年来，加拿大、美国和澳大利亚的平均森林火灾规模增加了一倍甚至两倍。反过来，森林火灾通过调节陆地—大气碳、氮、气溶胶、能量和水通量来反馈给气候。然而，越来越大的火灾对地表气候的影响及其对土地管理的影响仍有待确定。

附：英文原文

Title: Forest fire size amplifies postfire land surface warming

Author: Zhao, Jie, Yue, Chao, Wang, Jiaming, Hantson, Stijn, Wang, Xianli, He, Binbin, Li, Guangyao, Wang, Liang, Zhao, Hongfei, Luyssaert, Sebastiaan

Issue&Volume: 2024-09-25

Abstract: Climate warming has caused a widespread increase in extreme fire weather, making forest fires longer-lived and larger. The average forest fire size in Canada, the USA and Australia has doubled or even tripled in recent decades. In return, forest fires feed back to climate by modulating land–atmospheric carbon, nitrogen, aerosol, energy and water fluxes. However, the surface climate impacts of increasingly large fires and their implications for land management remain to be established. Here we use satellite observations to show that in temperate and boreal forests in the Northern Hemisphere, fire size persistently amplified decade-long postfire land surface warming in summer per unit burnt area. Both warming and its amplification with fire size were found to diminish with an increasing abundance of broadleaf trees, consistent with their lower fire vulnerability compared with coniferous species. Fire-size-enhanced warming may affect the success and composition of postfire stand regeneration as well as permafrost degradation, presenting previously overlooked, additional feedback effects to future climate and fire dynamics. Given the projected increase in fire size in northern forests, climate-smart forestry should aim to mitigate the climate risks of large fires, possibly by increasing the share of broadleaf trees, where appropriate, and avoiding active pyrophytes.

DOI: 10.1038/s41586-024-07918-8

Source: https://www.nature.com/articles/s41586-024-07918-8