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Effect of permafrost thaw on labile dissolved organic carbon in a northern palsa mire

Panneer Selvam, Balathandayuthabani LU ; Christensen, Torben LU ; Guillemette, Francois; Lapierre, Jean-François; Voigt, Carolina; Lamprecht, Richard E. and Berggren, Martin LU (2015) ASLO 2015 Aquatic Sciences Meeting
Abstract
Permafrost thaw can substantially increase the total export of dissolved organic carbon (DOC) to aquatic systems. The effects for bio- and photo-degradable DOC, however, are poorly known, because previous studies have mainly targeted lakes and streams which are indirectly affected by permafrost, while direct experimental work on permafrost thaw is lacking. We thus incubated permafrost cores from a northern palsa mire in a climate chamber to directly compare active layer and the effect of thaw on 1) DOC composition (using fluorescence analyses and PARAFAC modeling) and 2) DOC bioavailability and photo-degradability. Our results show that compared with DOC from the active layer, the permafrost-thaw DOC was more bioavailable, coherent with... (More)
Permafrost thaw can substantially increase the total export of dissolved organic carbon (DOC) to aquatic systems. The effects for bio- and photo-degradable DOC, however, are poorly known, because previous studies have mainly targeted lakes and streams which are indirectly affected by permafrost, while direct experimental work on permafrost thaw is lacking. We thus incubated permafrost cores from a northern palsa mire in a climate chamber to directly compare active layer and the effect of thaw on 1) DOC composition (using fluorescence analyses and PARAFAC modeling) and 2) DOC bioavailability and photo-degradability. Our results show that compared with DOC from the active layer, the permafrost-thaw DOC was more bioavailable, coherent with its optical characteristics indicating higher protein content and lower molecular weight DOC. This biolabile DOC, however, does not appear to contribute to photo-oxidation as we found no difference in photo-degradation between the active layer and permafrost DOC. Our study suggests that permafrost thaw results in the export of both bio- and photo-degradable DOC, indicating that an increase in permafrost thaw could positively affect the carbon cycling of aquatic ecosystems. (Less)
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ASLO 2015 Aquatic Sciences Meeting
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English
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0b290f68-29dc-4ffc-86d4-e2a705386296
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@misc{0b290f68-29dc-4ffc-86d4-e2a705386296,
  abstract     = {Permafrost thaw can substantially increase the total export of dissolved organic carbon (DOC) to aquatic systems. The effects for bio- and photo-degradable DOC, however, are poorly known, because previous studies have mainly targeted lakes and streams which are indirectly affected by permafrost, while direct experimental work on permafrost thaw is lacking. We thus incubated permafrost cores from a northern palsa mire in a climate chamber to directly compare active layer and the effect of thaw on 1) DOC composition (using fluorescence analyses and PARAFAC modeling) and 2) DOC bioavailability and photo-degradability. Our results show that compared with DOC from the active layer, the permafrost-thaw DOC was more bioavailable, coherent with its optical characteristics indicating higher protein content and lower molecular weight DOC. This biolabile DOC, however, does not appear to contribute to photo-oxidation as we found no difference in photo-degradation between the active layer and permafrost DOC. Our study suggests that permafrost thaw results in the export of both bio- and photo-degradable DOC, indicating that an increase in permafrost thaw could positively affect the carbon cycling of aquatic ecosystems.},
  author       = {Panneer Selvam, Balathandayuthabani and Christensen, Torben and Guillemette, Francois and Lapierre, Jean-François and Voigt, Carolina and Lamprecht,  Richard E. and Berggren, Martin},
  language     = {eng},
  pages        = {1},
  title        = {Effect of permafrost thaw on labile dissolved organic carbon in a northern palsa mire},
  year         = {2015},
}