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Effects of compositional changes on reactivity continuum and decomposition kinetics of lake dissolved organic matter

Title: Effects of compositional changes on reactivity continuum and decomposition kinetics of lake dissolved organic matter.
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Name(s): Mostovaya, Alina, author
Koehler, Birgit, author
Guillemette, Francois, author
Brunberg, Anna-Kristina, author
Tranvik, Lars J., author
Type of Resource: text
Genre: Text
Date Issued: 2016-07
Physical Form: computer
online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: To address the link between the composition and decomposition of freshwater dissolved organic matter (DOM), we manipulated the DOM from three boreal lakes using preincubations with UV light to cleave large aromatic molecules and polyvinylpyrrolidone (PVP) to remove colored phenolic compounds. Subsequently, we monitored the dissolved organic carbon (DOC) loss over 4months of microbial degradation in the dark to assess how compositional changes in DOM affected different aspects of the reactivity continuum, including the distribution of the apparent decay coefficients. We observed profound effects on decomposition kinetics, with pronounced shifts in the relative share of rapidly and more slowly decomposing fractions of the DOM. In the UV-exposed treatment initial apparent decay coefficient k(0) was almost threefold higher than in the control. Significantly higher relative DOC loss in the UV-exposed treatment was sustained for 2months of incubation, after which decay coefficients converged with those in the control. The PVP removed compounds with absorbance and fluorescence characteristics representative of aromatic compounds, which led to slower decomposition, compared to that in the control. Our results demonstrate the reactivity continuum underlying the decomposition of DOM in freshwaters and highlight the importance of intrinsic properties of DOM in determining its decomposition kinetics.
Identifier: FSU_libsubv1_wos_000382581900002 (IID), 10.1002/2016JG003359 (DOI)
Keywords: Carbon, decay, decomposition kinetics, Degradation, dissolved organic carbon, fluorescence spectroscopy, fresh-water ecosystems, marine-sediments, model, molecular signatures, photochemical transformation, soils
Publication Note: The publisher’s version of record is available at http://www.dx.doi.org/10.1002/2016JG003359
Persistent Link to This Record: http://purl.flvc.org/fsu/fd/FSU_libsubv1_wos_000382581900002
Owner Institution: FSU
Is Part Of: Journal of Geophysical Research-Biogeosciences.
2169-8953
Issue: iss. 7, vol. 121

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Mostovaya, A., Koehler, B., Guillemette, F., Brunberg, A. -K., & Tranvik, L. J. (2016). Effects of compositional changes on reactivity continuum and decomposition kinetics of lake dissolved organic matter. Journal Of Geophysical Research-Biogeosciences. Retrieved from http://purl.flvc.org/fsu/fd/FSU_libsubv1_wos_000382581900002