Diverse sediment microbiota shape methane emission temperature sensitivity in Arctic lakes

• Published in: Nature Communications
• Main Authors: Emerson, Joanne B., Varner, Ruth K., Wik, Martin, Parks, Donovan H., Neumann, Rebecca B., Johnson, Joel E., Singleton, Caitlin M., Woodcroft, Ben J., Tollerson, Rodney, Owusu-Dommey, Akosua, Binder, Morgan, Freitas, Nancy L., Crill, Patrick M., Saleska, Scott R., Tyson, Gene W., Rich, Virginia I.
• Other Authors: DOE | SC | Biological and Environmental Research, University of California, Davis College of Agricultural and Environmental Sciences and Department of Plant Pathology, NERU, National Science Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: General Physics and Astronomy; General Biochemistry, Genetics and Molecular Biology; General Chemistry; Arctic
• Online Access: http://dx.doi.org/10.1038/s41467-021-25983-9; https://www.nature.com/articles/s41467-021-25983-9.pdf; https://www.nature.com/articles/s41467-021-25983-9

Abstract Northern post-glacial lakes are significant, increasing sources of atmospheric carbon through ebullition (bubbling) of microbially-produced methane (CH 4 ) from sediments. Ebullitive CH 4 flux correlates strongly with temperature, reflecting that solar radiation drives emissions. However, here we show that the slope of the temperature-CH 4 flux relationship differs spatially across two post-glacial lakes in Sweden. We compared these CH 4 emission patterns with sediment microbial (metagenomic and amplicon), isotopic, and geochemical data. The temperature-associated increase in CH 4 emissions was greater in lake middles—where methanogens were more abundant—than edges, and sediment communities were distinct between edges and middles. Microbial abundances, including those of CH 4 -cycling microorganisms and syntrophs, were predictive of porewater CH 4 concentrations. Results suggest that deeper lake regions, which currently emit less CH 4 than shallower edges, could add substantially to CH 4 emissions in a warmer Arctic and that CH 4 emission predictions may be improved by accounting for spatial variations in sediment microbiota.