| Autor: |
Jan Karlsson, Georgia Destouni, Elin J. Jantze, Carl-Magnus Mörth, Christoph Humborg, Reiner Giesler, Steve W. Lyon |
| Rok vydání: |
2013 |
| Předmět: |
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| DOI: |
10.5194/bgd-10-7953-2013 |
| Popis: |
Climatic change is currently enhancing permafrost thawing and hydrological cycling in subarctic and arctic catchments with major consequences for the carbon export to aquatic ecosystems. We studied stream water carbon export in several tundra dominated catchments in northern Sweden. There were clear seasonal differences in both dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) concentrations. The highest DOC concentrations occurred during the spring freshet while the highest DIC concentrations were always observed during winter baseflow conditions for the six catchments considered in this study. In these subarctic catchments, DIC accounted for at least about half of the annual mass of C exported. Further, there was a direct relationship between both hydrologic flow pathway length and the maximum flow to minimum flow ratio (which serves as a proxy for fractioning between surface and subsurface flow pathways) and annual carbon fluxes for these six catchments. Further, these relationships were more prevalent for annual DIC exports than annual DOC exports in this region. These results highlight that there can be large regional differences in high latitude ecosystems and emphasize the importance of proper representation of subsurface hydrogeological conditions. This is particularly relevant in subarctic environments were thawing permafrost and changes to subsurface ice due to global warming can influence stream water fluxes of C. The large proportion of stream water DIC flux also has implications on regional C budgets and needs to be considered in order to understand climate induced feedback mechanisms across the landscape. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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