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Controls on Dissolved Organic Carbon Bioreactivity in River Systems

Soares, Ana R.A. LU ; Lapierre, Jean François ; Selvam, Balathandayuthabani P. ; Lindström, Göran and Berggren, Martin LU (2019) In Scientific Reports 9(1).
Abstract

Inland waters transport, transform and retain significant amounts of dissolved organic carbon (DOC) that may be biologically reactive (bioreactive) and thus potentially degraded into atmospheric CO2. Despite its global importance, relatively little is known about environmental controls on bioreactivity of DOC as it moves through river systems with varying water residence time (WRT). Here we determined the influence of WRT and landscape properties on DOC bioreactivity in 15 Swedish catchments spanning a large geographical and environmental gradient. We found that the short-term bioreactive pools (0–6 d of decay experiments) were linked to high aquatic primary productivity that, in turn, was stimulated by phosphorus loading... (More)

Inland waters transport, transform and retain significant amounts of dissolved organic carbon (DOC) that may be biologically reactive (bioreactive) and thus potentially degraded into atmospheric CO2. Despite its global importance, relatively little is known about environmental controls on bioreactivity of DOC as it moves through river systems with varying water residence time (WRT). Here we determined the influence of WRT and landscape properties on DOC bioreactivity in 15 Swedish catchments spanning a large geographical and environmental gradient. We found that the short-term bioreactive pools (0–6 d of decay experiments) were linked to high aquatic primary productivity that, in turn, was stimulated by phosphorus loading from forested, agricultural and urban areas. Unexpectedly, the percentage of long-term bioreactive DOC (determined in 1-year experiments) increased with WRT, possibly due to photo-transformation of recalcitrant DOC from terrestrial sources into long-term bioreactive DOC with relatively lower aromaticity. Thus, despite overall decreases in DOC during water transit through the inland water continuum, DOC becomes relatively more bioreactive on a long time-scale. This increase in DOC bioreactivity with increasing WRT along the freshwater continuum has previously been overlooked. Further studies are needed to explain the processes and mechanisms behind this pattern on a molecular level.

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author
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type
Contribution to journal
publication status
published
subject
in
Scientific Reports
volume
9
issue
1
article number
14897
publisher
Nature Publishing Group
external identifiers
  • pmid:31624278
  • scopus:85073561728
ISSN
2045-2322
DOI
10.1038/s41598-019-50552-y
language
English
LU publication?
yes
id
9f94de9c-b163-45e3-a213-1548e7ebc5f8
date added to LUP
2019-10-25 12:02:32
date last changed
2021-01-19 04:09:43
@article{9f94de9c-b163-45e3-a213-1548e7ebc5f8,
  abstract     = {<p>Inland waters transport, transform and retain significant amounts of dissolved organic carbon (DOC) that may be biologically reactive (bioreactive) and thus potentially degraded into atmospheric CO<sub>2</sub>. Despite its global importance, relatively little is known about environmental controls on bioreactivity of DOC as it moves through river systems with varying water residence time (WRT). Here we determined the influence of WRT and landscape properties on DOC bioreactivity in 15 Swedish catchments spanning a large geographical and environmental gradient. We found that the short-term bioreactive pools (0–6 d of decay experiments) were linked to high aquatic primary productivity that, in turn, was stimulated by phosphorus loading from forested, agricultural and urban areas. Unexpectedly, the percentage of long-term bioreactive DOC (determined in 1-year experiments) increased with WRT, possibly due to photo-transformation of recalcitrant DOC from terrestrial sources into long-term bioreactive DOC with relatively lower aromaticity. Thus, despite overall decreases in DOC during water transit through the inland water continuum, DOC becomes relatively more bioreactive on a long time-scale. This increase in DOC bioreactivity with increasing WRT along the freshwater continuum has previously been overlooked. Further studies are needed to explain the processes and mechanisms behind this pattern on a molecular level.</p>},
  author       = {Soares, Ana R.A. and Lapierre, Jean François and Selvam, Balathandayuthabani P. and Lindström, Göran and Berggren, Martin},
  issn         = {2045-2322},
  language     = {eng},
  number       = {1},
  publisher    = {Nature Publishing Group},
  series       = {Scientific Reports},
  title        = {Controls on Dissolved Organic Carbon Bioreactivity in River Systems},
  url          = {http://dx.doi.org/10.1038/s41598-019-50552-y},
  doi          = {10.1038/s41598-019-50552-y},
  volume       = {9},
  year         = {2019},
}