Characteristics of methane emissions from alpine thermokarst lakes on the Tibetan Plateau.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37253726.
- Also identified by DOI 10.1038/s41467-023-38907-6 and PMC identifier 10229571.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Understanding methane (CH<sub>4</sub>) 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 CH<sub>4</sub> emissions from 120 thermokarst lakes in 30 clusters along a 1100 km transect on the Tibetan Plateau. We find that thermokarst lakes have high CH<sub>4</sub> emissions during the ice-free period (13.4 ± 1.5 mmol m<sup>-2</sup> d<sup>-1</sup>; mean ± standard error) across this alpine permafrost region. Ebullition constitutes 84% of CH<sub>4</sub> emissions, which are fueled primarily by young carbon decomposition through the hydrogenotrophic pathway. The relative abundances of methanogenic genes correspond to the observed CH<sub>4</sub> 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.