Divergent biophysical controls of aquatic CO2 and CH4 in the World's two largest rivers
|Author(s)||Borges Alberto V.1, Abril Gwenael2, 3, Darchambeau Francois1, Teodoru Cristian R.4, Deborde Jonathan2, Vidal Luciana O.5, Lambert Thibault1, Bouillon Steven4|
|Affiliation(s)||1 : Univ Liege, Inst Phys B5, Unite Oceanog Chim, B-4000 Liege, Belgium.
2 : Univ Bordeaux 1, CNRS, Lab Environm & Paleoenvironm Ocean & Continentaux, F-33405 Talence, France.
3 : Univ Fed Fluminense, Programa Geoquim, BR-24020015 Niteroi, RJ, Brazil.
4 : Katholieke Univ Leuven, Dept Earth & Environm Sci, B-3001 Louvain, Belgium.
5 : Univ Estadual N Fluminen, Ctr Biociencias & Biotecnol, Lab Ciencias Ambientais, BR-28013602 Campos dos Goytacazes, RJ, Brazil.
|Source||Scientific Reports (2045-2322) (Nature Publishing Group), 2015-10 , Vol. 5 , N. 15614 , P. 10p.|
|WOS© Times Cited||60|
Carbon emissions to the atmosphere from inland waters are globally significant and mainly occur at tropical latitudes. However, processes controlling the intensity of CO2 and CH4 emissions from tropical inland waters remain poorly understood. Here, we report a data-set of concurrent measurements of the partial pressure of CO2 (pCO(2)) and dissolved CH4 concentrations in the Amazon (n = 136) and the Congo (n = 280) Rivers. The pCO(2) values in the Amazon mainstem were significantly higher than in the Congo, contrasting with CH4 concentrations that were higher in the Congo than in the Amazon. Large-scale patterns in pCO(2) across different lowland tropical basins can be apprehended with a relatively simple statistical model related to the extent of wetlands within the basin, showing that, in addition to non-flooded vegetation, wetlands also contribute to CO2 in river channels. On the other hand, dynamics of dissolved CH4 in river channels are less straightforward to predict, and are related to the way hydrology modulates the connectivity between wetlands and river channels.