Characteristics of methane emissions from alpine thermokarst lakes on the Tibetan Plateau

• Published in: Nature Communications
• Main Authors: Guibiao Yang, Zhihu Zheng, Benjamin W. Abbott, David Olefeldt, Christian Knoblauch, Yutong Song, Luyao Kang, Shuqi Qin, Yunfeng Peng, Yuanhe Yang
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2023
• Subjects: Science; Q; Ice; permafrost; Thermokarst
• Online Access: https://doi.org/10.1038/s41467-023-38907-6; https://doaj.org/article/f0d5208d96cf4cfe904021a1f5fc7e8f

Abstract Understanding methane (CH4) emission from thermokarst lakes is crucial for predicting the impacts of abrupt thaw on the permafrost carbon-climate feedback. However, observational evidence, especially from high-altitude permafrost regions, is still scarce. Here, by combining field surveys, radio- and stable-carbon isotopic analyses, and metagenomic sequencing, we present multiple characteristics of CH4 emissions from 120 thermokarst lakes in 30 clusters along a 1100 km transect on the Tibetan Plateau. We find that thermokarst lakes have high CH4 emissions during the ice-free period (13.4 ± 1.5 mmol m−2 d−1; mean ± standard error) across this alpine permafrost region. Ebullition constitutes 84% of CH4 emissions, which are fueled primarily by young carbon decomposition through the hydrogenotrophic pathway. The relative abundances of methanogenic genes correspond to the observed CH4 fluxes. Overall, multiple parameters obtained in this study provide benchmarks for better predicting the strength of permafrost carbon-climate feedback in high-altitude permafrost regions.