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| Titel |
CO2 and CH4 supersaturation of headwater streams across forested Sweden |
| VerfasserIn |
M. Wallin, S. Löfgren, K. Bishop |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250070395
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| Zusammenfassung |
| Lateral export of carbon (C) from soils to running waters is a persistent pathway for C with
terrestrial origin. This “aquatic conduit” might be especially important in boreal regions
where a significant part of the global C stock is stored in the soil. Even though the awareness
of the fate of terrestrially derived C is increasing in regional and global C budgets, the
scarcity of data on the contribution of streams is widely acknowledged. In particular, the
evasion (degassing) of gaseous C (i.e. CO2 and CH4) from the water surface of streams
requires better characterization.
In this study we present CO2 and CH4 data from ~200 randomly selected headwater streams
in forested catchments along the west coast and in the central part of Sweden. The streams
were sampled by headspace technique at four occasions during different seasons to cover
seasonal dynamics. All streams, independent of season, were supersaturated in CO2 (median
pCO2=2763 μatm) and a majority (~60%) in CH4. There were however large seasonal
variability and with indications that the main source of dissolved inorganic carbon (DIC)
(geogenic vs. biogenic) varies both with space and time. To determine the source of the DIC
is important when including aquatic C fluxes into the terrestrial C balance. Without this
information the source strength of evasion from headwater streams will remain
uncertain |
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