Salinity causes widespread restriction of methane emissions from small inland waters
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Date
2024
Authors
Soued, Cynthia
Bogard, Matthew J.
Finlay, Kerri
Bortolotti, Lauren E.
Leavitt, Peter R.
Badiou, Pascal
Knox, Sara H.
Jensen, Sydney
Mueller, Peka
Lee, Sung Ching
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Nature
Abstract
Inland waters are one of the largest natural sources of methane (CH4), a potent greenhouse gas, but emissions models and estimates were developed for solute-poor ecosystems and may not apply to salt-rich inland waters. Here we combine field surveys and eddy covariance measurements to show that salinity constrains microbial CH4 cycling through complex mechanisms, restricting aquatic emissions from one of the largest global hardwater regions (the Canadian Prairies). Existing models overestimated CH4 emissions from ponds and wetlands by up to several orders of magnitude, with discrepancies linked to salinity. While not significant for rivers and larger lakes, salinity interacted with organic matter availability to shape CH4 patterns in small lentic habitats. We estimate that excluding salinity leads to overestimation of emissions from small Canadian Prairie waterbodies by at least 81% ( ~ 1 Tg yr−1 CO2 equivalent), a quantity comparable to other major national emissions sources. Our findings are consistent with patterns in other hardwater landscapes, likely leading to an overestimation of global lentic CH4 emissions. Widespread salinization of inland waters may impact CH4 cycling and should be considered in future projections of aquatic emissions.
Description
Open access article. Creative Commons Attribution 4.0 International license (CC BY 4.0) applies
Keywords
Carbon cycle , Ecosystem ecology , Geochemistry , Limnology , Methane emissions , Salinity , Inland waters
Citation
Soued, C., Bogard, M. J., Finlay, K., Bortolotti, L. E., Leavitt, P. R., Badiou, P., Know, S. H., Jensen, S., Mueller, P., Lee, S. C., Ng, D., Wissel, B., Chan, C. N., Page, B., & Kowal, P. (2024). Salinity causes widespread restriction of methane emissions from small inland waters. Nature Communications, 15, Article 717. https://doi.org/10.1038/s41467-024-44715-3