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Title: Diverse sediment microbiota shape methane emission temperature sensitivity in Arctic lakes
Abstract

Northern post-glacial lakes are significant, increasing sources of atmospheric carbon through ebullition (bubbling) of microbially-produced methane (CH4) from sediments. Ebullitive CH4flux correlates strongly with temperature, reflecting that solar radiation drives emissions. However, here we show that the slope of the temperature-CH4flux relationship differs spatially across two post-glacial lakes in Sweden. We compared these CH4emission patterns with sediment microbial (metagenomic and amplicon), isotopic, and geochemical data. The temperature-associated increase in CH4emissions 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 CH4-cycling microorganisms and syntrophs, were predictive of porewater CH4concentrations. Results suggest that deeper lake regions, which currently emit less CH4than shallower edges, could add substantially to CH4emissions in a warmer Arctic and that CH4emission predictions may be improved by accounting for spatial variations in sediment microbiota.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Award ID(s):
2022070
Publication Date:
NSF-PAR ID:
10305337
Journal Name:
Nature Communications
Volume:
12
Issue:
1
ISSN:
2041-1723
Publisher:
Nature Publishing Group
Sponsoring Org:
National Science Foundation
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