英国伯明翰大学Gauci, Vincent团队在研究高地树木木质表面对全球大气甲烷的吸收上取得新进展。相关论文发表在2024年7月24日出版的《自然》杂志上。

团队人员研究了高地热带、温带和北方森林树木的原位木本表面甲烷交换。研究发现，木质表面的甲烷吸收量，特别是在森林地面以上约2m处和以上，可以支配树木对生态系统的净贡献，结果是树木的净甲烷汇。木质表面空气中甲烷的稳定碳同位素测量和提取木芯的过程水平研究与甲烷化一致，表明微生物介导的木材表面和组织中的甲烷减少。

通过应用地面激光扫描衍生的异速测量来量化全球森林树木木材表面积，初步估计树木可能贡献24.6-49.9 Tg的全球大气甲烷吸收量。研究结果强调，热带和温带森林保护和再造林的气候效益可能比以前假设的要大。

据悉，甲烷是一种重要的温室气体，但树木在甲烷收支中的作用仍不确定。虽然已有研究表明，湿地和一些高地树木可以在树干基部释放土壤衍生的甲烷，但也有研究表明，高地树木可以作为大气甲烷的净汇。

附：英文原文

Title: Global atmospheric methane uptake by upland tree woody surfaces

Author: Gauci, Vincent, Pangala, Sunitha Rao, Shenkin, Alexander, Barba, Josep, Bastviken, David, Figueiredo, Viviane, Gomez, Carla, Enrich-Prast, Alex, Sayer, Emma, Stauffer, Tain, Welch, Bertie, Elias, Dafydd, McNamara, Niall, Allen, Myles, Malhi, Yadvinder

Issue&Volume: 2024-07-24

Abstract: Methane is an important greenhouse gas, but the role of trees in the methane budget remains uncertain. Although it has been shown that wetland and some upland trees can emit soil-derived methane at the stem base, it has also been suggested that upland trees can serve as a net sink for atmospheric methane. Here we examine in situ woody surface methane exchange of upland tropical, temperate and boreal forest trees. We find that methane uptake on woody surfaces, in particular at and above about 2m above the forest floor, can dominate the net ecosystem contribution of trees, resulting in a net tree methane sink. Stable carbon isotope measurement of methane in woody surface chamber air and process-level investigations on extracted wood cores are consistent with methanotrophy, suggesting a microbially mediated drawdown of methane on and in tree woody surfaces and tissues. By applying terrestrial laser scanning-derived allometry to quantify global forest tree woody surface area, a preliminary first estimate suggests that trees may contribute 24.6–49.9Tg of atmospheric methane uptake globally. Our findings indicate that the climate benefits of tropical and temperate forest protection and reforestation may be greater than previously assumed.

DOI: 10.1038/s41586-024-07592-w

Source: https://www.nature.com/articles/s41586-024-07592-w