Chemodiversity of dissolved organic matter in the Amazon Basin
-
Published:2016-07-29
Issue:14
Volume:13
Page:4279-4290
-
ISSN:1726-4189
-
Container-title:Biogeosciences
-
language:en
-
Short-container-title:Biogeosciences
Author:
Gonsior MichaelORCID, Valle Juliana, Schmitt-Kopplin Philippe, Hertkorn Norbert, Bastviken DavidORCID, Luek Jenna, Harir Mourad, Bastos Wanderley, Enrich-Prast Alex
Abstract
Abstract. Regions in the Amazon Basin have been associated with specific biogeochemical processes, but a detailed chemical classification of the abundant and ubiquitous dissolved organic matter (DOM), beyond specific indicator compounds and bulk measurements, has not yet been established. We sampled water from different locations in the Negro, Madeira/Jamari and Tapajós River areas to characterize the molecular DOM composition and distribution. Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) combined with excitation emission matrix (EEM) fluorescence spectroscopy and parallel factor analysis (PARAFAC) revealed a large proportion of ubiquitous DOM but also unique area-specific molecular signatures. Unique to the DOM of the Rio Negro area was the large abundance of high molecular weight, diverse hydrogen-deficient and highly oxidized molecular ions deviating from known lignin or tannin compositions, indicating substantial oxidative processing of these ultimately plant-derived polyphenols indicative of these black waters. In contrast, unique signatures in the Madeira/Jamari area were defined by presumably labile sulfur- and nitrogen-containing molecules in this white water river system. Waters from the Tapajós main stem did not show any substantial unique molecular signatures relative to those present in the Rio Madeira and Rio Negro, which implied a lower organic molecular complexity in this clear water tributary, even after mixing with the main stem of the Amazon River. Beside ubiquitous DOM at average H ∕ C and O ∕ C elemental ratios, a distinct and significant unique DOM pool prevailed in the black, white and clear water areas that were also highly correlated with EEM-PARAFAC components and define the frameworks for primary production and other aspects of aquatic life.
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Ecology, Evolution, Behavior and Systematics
Reference58 articles.
1. Amado, A. M., Farjalla, V. F., Esteves, F. D. A., Bozelli, R. L., Roland, F., and Enrich-Prast, A.: Complementary pathways of dissolved organic carbon removal pathways in clear-water Amazonian ecosystems: photochemical degradation and bacterial uptake, Fems Microbiol. Ecol., 56, 8–17, https://doi.org/10.1111/j.1574-6941.2006.00028.x, 2006. 2. Aucour, A. M., Tao, F. X., Moreira-Turcq, P., Seyler, P., Sheppard, S., and Benedetti, M. F.: The Amazon River: behaviour of metals (Fe, Al, Mn) and dissolved organic matter in the initial mixing at the Rio Negro/Solimões confluence, Chem. Geol., 197, 271–285, https://doi.org/10.1016/S0009-2541(02)00398-4, 2003. 3. Benner, R., Opsahl, S., ChinLeo, G., Richey, J. E., and Forsberg, B. R.: Bacterial carbon metabolism in the Amazon River system, Limnol. Oceanogr., 40, 1262–1270, 1995. 4. Boutegrabet, L., Kanawati, B., Gebefügi, I., Peyron, D., Cayot, P., Gougeon, R. D., and Schmitt-Kopplin, P.: Attachment of Chloride Anion to Sugars: Mechanistic Investigation and Discovery of a New Dopant for Efficient Sugar Ionization/Detection in Mass Spectrometers, Chem.-Eur. J., 18, 13059–13067, https://doi.org/10.1002/chem.201103788, 2012. 5. Bro, R. and Smilde, A. K.: Principal component analysis, Anal. Meth., 6, 2812–2831, https://doi.org/10.1039/c3ay41907j, 2014.
Cited by
51 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|