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Titel |
Assessing the biodegradability of terrestrially-derived organic matter in Scottish sea loch sediments |
VerfasserIn |
P. S. Loh, A. E. J. Miller, A. D. Reeves, S. M. Harvey, J. Overnell |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 12, no. 3 ; Nr. 12, no. 3 (2008-05-26), S.811-823 |
Datensatznummer |
250010659
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Publikation (Nr.) |
copernicus.org/hess-12-811-2008.pdf |
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Zusammenfassung |
Lignin oxidation products, oxygen uptake rates, molar organic carbon to
nitrogen (OC/N) ratio (from bulk elemental analysis) and Rp values (from
loss on ignition experiments, the ratio of the refractory to total organic
matter, OM) were determined for sediments along transects of Loch Creran and
Loch Etive. Lignin data indicated the importance of riverine inputs
contributing to land-derived carbon in the lochs as total lignin (Λ, mg/100 mg
organic carbon, OC) decreased from 0.69 to 0.45 and 0.70 to
0.29 from the head to outside of Loch Creran and Loch Etive, respectively.
In addition, significant correlations of lignin content against total OM and
OC (p<0.05) also suggested a distinct contribution of terrestrial OM to
carbon pools in the lochs. The general trend of decreasing oxygen uptake
rates from the head (20.8 mmole m−2 day−1) to mouth (9.4 mmole m−2 day−1)
of Loch Creran indicates decomposition of OM.
Biodegradability of the sedimentary OM was also characterized by the
increase of Rp values from the head to mouth of the lochs: 0.40 to 0.80 in
Loch Etive and 0.43 to 0.63 in Loch Creran. Furthermore, the molar OC/N
ratio decreased from 11.2 to 6.4 in Loch Creran, and from 17.5 to 8.2 in
Loch Etive. Derived rate constants for OM degradation were found to decrease
from LC0 to LC1, and increase from RE5 to RE6. This work demonstrates that
oxygen uptake rates, Rp values and molar OC/N ratio are able to serve as
useful proxies to indicate the biodegradability of sedimentary OM. |
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