Global atmospheric methane uptake by upland tree woody surfaces

• 成果类型: Article
• 署名作者: Gauci, Vincent; Pangala, Sunitha Rao; Shenkin, Alexander; Barba, Josep; Bastviken, David; Figueiredo, Viviane; Gomez, Carla; Enrich-Prast, Alex; Sayer, Emma; Stauffer, Taina; Welch, Bertie; Elias, Dafydd; McNamara, Niall; Allen, Myles; Malhi, Yadvinder
• 署名单位: University of Birmingham; University of Birmingham; Lancaster University; Northern Arizona University; Centro de Investigacion Ecologica y Aplicaciones Forestales (CREAF-CERCA); Linkoping University; Open University - UK; Universidade Federal do Rio de Janeiro; Universidade Federal de Sao Paulo (UNIFESP); Smithsonian Institution; Smithsonian Tropical Research Institute; Ulm University; Lancaster University; UK Centre for Ecology & Hydrology (UKCEH); University of Oxford; University of Oxford; University of Oxford
• 刊物名称: Nature
• ISSN/ISSBN: 0028-4930
• DOI: 10.1038/s41586-024-07592-w
• 发表日期: 2024-07-25
• 关键词: litter manipulation; forest; soils; emission; flux

摘要

Methane is an important greenhouse gas1, but the role of trees in the methane budget remains uncertain2. Although it has been shown that wetland and some upland trees can emit soil-derived methane at the stem base3,4, it has also been suggested that upland trees can serve as a net sink for atmospheric methane5,6. 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 2 m 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 24.6-49.9 Tg 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. Studies of in situ woody surface methane exchange in upland tropical, temperate and boreal forest trees find that methane uptake can result in a net tree methane sink that is globally significant and demonstrates an additional climate benefit provided by trees.