Oxidative mitigation of aquatic methane emissions in large Amazonian rivers
© 2015 John Wiley & Sons Ltd.
| Publié dans: | Global change biology. - 1999. - 22(2016), 3 vom: 15. März, Seite 1075-85 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2016
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| Accès à la collection: | Global change biology |
| Sujets: | Journal Article Research Support, Non-U.S. Gov't Amazon CH4 greenhouse gas methane oxidation methanotrophs pmoA gene sink tropical rivers plus... |
| Résumé: | © 2015 John Wiley & Sons Ltd. The flux of methane (CH4 ) from inland waters to the atmosphere has a profound impact on global atmospheric greenhouse gas (GHG) levels, and yet, strikingly little is known about the dynamics controlling sources and sinks of CH4 in the aquatic setting. Here, we examine the cycling and flux of CH4 in six large rivers in the Amazon basin, including the Amazon River. Based on stable isotopic mass balances of CH4 , inputs and outputs to the water column were estimated. We determined that ecosystem methane oxidation (MOX) reduced the diffusive flux of CH4 by approximately 28-96% and varied depending on hydrologic regime and general geochemical characteristics of tributaries of the Amazon River. For example, the relative amount of MOX was maximal during high water in black and white water rivers and minimal in clear water rivers during low water. The abundance of genetic markers for methane-oxidizing bacteria (pmoA) was positively correlated with enhanced signals of oxidation, providing independent support for the detected MOX patterns. The results indicate that MOX in large Amazonian rivers can consume from 0.45 to 2.07 Tg CH4 yr(-1) , representing up to 7% of the estimated global soil sink. Nevertheless, climate change and changes in hydrology, for example, due to construction of dams, can alter this balance, influencing CH4 emissions to atmosphere |
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| Description: | Date Completed 02.11.2016 Date Revised 30.12.2016 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1365-2486 |
| DOI: | 10.1111/gcb.13169 |