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Seasonal changes in the age and structure of dissolved organic carbon in Siberian rivers and streams
Author(s) -
Neff J. C.,
Finlay J. C.,
Zimov S. A.,
Davydov S. P.,
Carrasco J. J.,
Schuur E. A. G.,
Davydova A. I.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl028222
Subject(s) - dissolved organic carbon , radiocarbon dating , tributary , environmental science , streams , spring (device) , total organic carbon , hydrology (agriculture) , environmental chemistry , leaching (pedology) , soil water , geology , oceanography , chemistry , soil science , geography , computer network , geotechnical engineering , computer science , mechanical engineering , paleontology , cartography , engineering
We examined the age and structural composition of dissolved organic carbon (DOC) transported in the Kolyma River, two large tributaries and several small upland and lowland streams in 2003. The sampling took place under ice through the winter and included the spring flood period. Radiocarbon measurements of the DOC indicated that the bulk of the annual DOC flux was modern in origin (Δ 14 C > 100‰) and pyrolysis‐gas chromatography/mass spectroscopy techniques showed high concentration of terrestrial lignin monomers consistent with vigorous leaching of surface horizons during the spring thaw. By September 2003 however, little terrestrial lignin was present and the radiocarbon age became significantly older (Δ 14 C < 0‰) indicating that the mechanism of DOC generation transitions from surface to deeper soils or other terrestrial sources of old, previously stabilized C.