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| Titel |
Dissolved organic carbon characteristics in surface ponds from contrasting wetland ecosystems: a case study in the Sanjiang Plain, Northeast China |
| VerfasserIn |
L. L. Wang, C. C. Song, G. S. Yang |
| 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 ; 17, no. 1 ; Nr. 17, no. 1 (2013-01-29), S.371-378 |
| Datensatznummer |
250017696
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| Publikation (Nr.) |
 copernicus.org/hess-17-371-2013.pdf |
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| Zusammenfassung |
| Dissolved organic carbon (DOC) is a significant component of carbon and
nutrient cycling in fluvial ecosystems. Natural wetlands, as important DOC
sources for river and ocean ecosystems, have experienced extensive natural
and anthropogenic disturbances such as climate change, hydrological
variations and land use change in recent years. The DOC characteristics in
surface ponds from contrasting wetlands in the Sanjiang Plain, Northeastern
China were investigated. Surface ponds at seven sites (two natural
phialiform wetlands, three natural riparian wetlands, one degraded wetland
and one artificial wetland, i.e., rice paddy) were monitored during the
growing seasons of 2009 and 2010. The results show that the surface ponds at
the five natural wetland sites exhibited a wide range of DOC concentrations
(10.06–48.73 mg L−1) during the study period. The DOC concentrations showed
no annual differences (P > 0.05) at all the wetland sites, except
one of the phialiform wetland sites. The two phialiform wetlands exhibited
higher DOC concentrations than the three riparian wetlands (P < 0.05).
The DOC concentration in the surface pond at the artificial wetland site was
relatively low (P < 0.05) compared to that at the degraded wetland
site. The C/C ratios (the color per carbon unit ratio, Abs400/DOC
concentration) showed inconsistent variations among these seven wetland
sites, while the E4/E6 ratio (Abs465/Abs665, fulvic acid/humic
acid) from the surface pond in the rice paddy land exerted 42.07–55.36%
reductions (P < 0.05), compared to those at the five natural wetland
sites. Furthermore, the E4/E6 ratio in the surface pond at the rice paddy
site was significantly lower compared to that at the degraded wetland site
(P < 0.05), which indicated that disturbance to wetland DOC in surface
ponds might be stronger when natural wetlands were converted to rice paddies
in comparison with wetland degradation. This study could not only provide
insightful points for understanding the aquatic DOC dynamics from different
wetland ecosystems, but also support data information for incorporating the
aquatic DOC into the model for regional carbon budgets in the future. |
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