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| Titel |
Carbon fluxes in an acid rain impacted boreal headwater catchment |
| VerfasserIn |
Anne Marx, Simone Hintze, Jakub Jankovec, Martin Sanda, Jaromir Dusek, Tomas Vogel, Robert van Geldern, Johannes A. C. Barth |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250128306
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| Publikation (Nr.) |
 EGU/EGU2016-8286.pdf |
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| Zusammenfassung |
| Terrestrial carbon export via inland aquatic systems is a key process in the budget of
the global carbon cycle. This includes loss of carbon to the atmosphere via gas
evasion from rivers or reservoirs as well as carbon fixation in freshwater sediments.
Headwater streams are the first endmembers of the transition of carbon between soils,
groundwater and surface waters and the atmosphere. In order to quantify these
processes the experimental catchment Uhlirska (1.78 km2) located in the northern
Czech Republic was studied. Dissolved inorganic, dissolved organic and particulate
organic carbon (DIC, DOC, POC) concentrations and isotopes were analyzed in
ground-, soil -and stream waters between 2014 and 2015. In addition, carbon dioxide
degassing was quantified via a stable isotope modelling approach. Results show a
discharge-weighted total carbon export of 31.99 g C m−2 yr−1 of which CO2 degassing
accounts 79 %. Carbon isotope ratios (δ13C) of DIC, DOC, and POC (in ‰ VPDB)
ranged from -26.6 to -12.4 ‰ from -29.4 to -22.7 ‰ and from -30.6 to -26.6 ‰
respectively. The mean values for DIC are -21.8 ±3.8 ‰ -23.6 ±0.9 ‰ and -19.5
±3.0 ‰ for soil, shallow ground and surface water compartments. For DOC, these
compartments have mean values of -27.1 ±0.3 ‰ -27.0 ±0.8 ‰ and -27.4 ±0.7 ‰Ṁean
POC value of shallow groundwaters and surface waters are -28.8 ±0.8 ‰ and
-29.3 ±0.5 ‰ respectively. These isotope ranges indicate little turnover of organic
material and predominant silicate weathering. The degassing of CO2 caused an
enrichment of the δ13C-DIC values of up to 6.8 ‰ between a catchment gauge and the
catchment outlet over a distance of 866 m. In addition, the Uhlirska catchment has
only negligible natural sources of sulphate, yet SO42− accounts for 21 % of major
stream water ions. This is most likely a remainder from acid rain impacts in the area. |
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