近日，南京大学江飞团队报道了加拿大森林净二氧化碳吸收量因热干旱通过减少呼吸而增加。相关论文于2026年1月5日发表在《自然—地球科学》杂志上。

森林净碳吸收对极端高温的响应仍然难以捉摸。2023年当时是全球“有记录以来最热的一年”，加拿大森林经历了2摄氏度以上的异常高温以及前所未有的干旱和野火，这为研究北方森林净碳吸收对极端气候的响应提供了一个独特案例。

研究组将基于卫星的大气二氧化碳通量反演与基于地面的二氧化碳通量和浓度原位观测相结合，以研究2023年加拿大森林的净碳吸收量及其潜在机制。结果发现，与2015年至2022年相比，2023年加拿大森林的净碳吸收量增加了0.28±0.23 PgC，抵消了加拿大2023年野火排放量的38%至48%。

这种净吸收量的增加主要是由于生态系统呼吸作用的大幅减少，而这一减少主要归因于根区土壤水分严重亏缺以及呼吸作用对温度的单峰响应。然而，大多数动态全球植被模型未能很好地模拟呼吸作用的减少以及对水热条件的响应。该研究加深了学界对北方森林净碳吸收量对极端气候响应的理解，并强调了在全球变暖背景下改进植被模型的迫切需求。

附：英文原文

Title: Canadian net forest CO2 uptake enhanced by heat drought via reduced respiration

Author: Dong, Guanyu, Jiang, Fei, Zhang, Yongguang, Ju, Weimin, Piao, Shilong, Ciais, Philippe, Peters, Wouter, Luijkx, Ingrid T., Liu, Junjie, Chevallier, Frdric, Zeng, Ning, Tian, Xiangjun, Maksyutov, Shamil, Sonnentag, Oliver, Arain, M. Altaf, Barr, Alan G., Huang, Yuanyuan, Yue, Chao, Yuan, Wenping, Liu, Liangyun, Fan, Lei, Yue, Xu, Xiao, Jingfeng, Li, Xing, Sitch, Stephen, Friedlingstein, Pierre, OSullivan, Michael, Knauer, Jrgen, Arora, Vivek, Kennedy, Daniel, Ma, Lei, Thornton, Peter E., Sfrian, Roland, Ntzel, Tobias, Heinke, Jens, Sun, Qing, Zaehle, Snke, Peylin, Philippe, Kato, Etsushi, Alcock, Haley, Lecavalier, Bruno, Wu, Mousong, Wang, Jun, Zhang, Lingyu, Lv, Guoyuan, Zhang, Yuanyuan, Zhao, Dayang, Chen, Jing M.

Issue&Volume: 2026-01-05

Abstract: The response of net forest carbon uptake to warm extremes remains elusive. The year 2023 was at the time ‘the hottest year on record’ globally, with Canada’s forests experiencing warm anomalies of above 2°C and unprecedented drought and wildfires, providing a unique case to examine the response of boreal forest net carbon uptake to climate extremes. Here we combine satellite-based atmospheric CO2 flux inversions with ground-based in situ observations of CO2 fluxes and concentrations to investigate Canada’s forest net carbon uptake and its underlying mechanisms in 2023. We find that, compared with 2015–2022, Canada’s forest net carbon uptake was enhanced by 0.28±0.23PgC, offsetting 38–48% of Canadian wildfire emissions in 2023. This enhanced net uptake was dominated by large ecosystem respiration reductions, mainly attributable to severe root-zone soil moisture deficits and the unimodal temperature response of respiration. However, most dynamic global vegetation models failed to simulate the respiration reductions and the responses to hydrothermal conditions well. This study improves our understanding of boreal forest net carbon uptake in response to climate extremes and highlights an urgent need to improve vegetation models under global warming.

DOI: 10.1038/s41561-025-01875-1

Source: https://www.nature.com/articles/s41561-025-01875-1