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USGS · 70182178

Source limitation of carbon gas emissions in high-elevation mountain streams and lakes

John T. Crawford·Mark M. Dornblaser·Emily H. Stanley·David W. Clow·Robert G. Striegl
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Abstract

Inland waters are an important component of the global carbon cycle through transport, storage, and direct emissions of CO 2 and CH 4 to the atmosphere. Despite predictions of high physical gas exchange rates due to turbulent flows and ubiquitous supersaturation of CO 2 —and perhaps also CH 4 —patterns of gas emissions are essentially undocumented for high mountain ecosystems. Much like other headwater networks around the globe, we found that high-elevation streams in Rocky Mountain National Park, USA, were supersaturated with CO 2 during the growing season and were net sources to the atmosphere. CO 2 concentrations in lakes, on the other hand, tended to be less than atmospheric equilibrium during the open water season. CO 2 and CH 4 emissions from the aquatic conduit were relatively small compared to many parts of the globe. Irrespective of the physical template for high gas exchange (high k ), we found evidence of CO 2 source limitation to mountain streams during the growing season, which limits overall CO 2 emissions. Our results suggest a reduced importance of aquatic ecosystems for carbon cycling in high-elevation landscapes having limited soil development and high CO 2 consumption via mineral weathering.

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Journal of Geophysical Research G: BiogeosciencesArticle

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John T. Crawford, Mark M. Dornblaser, Emily H. Stanley, David W. Clow, Robert G. Striegl. 2015-05-26. Source limitation of carbon gas emissions in high-elevation mountain streams and lakes. https://doi.org/10.1002/2014jg002861

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