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| Titel |
Patterns and persistence of hydrologic carbon and nutrient export from collapsing upland permafrost |
| VerfasserIn |
B. W. Abbott, J. B. Jones, S. E. Godsey, J. R. Larouche, W. B. Bowden |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 12 ; Nr. 12, no. 12 (2015-06-17), S.3725-3740 |
| Datensatznummer |
250117990
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| Publikation (Nr.) |
 copernicus.org/bg-12-3725-2015.pdf |
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| Zusammenfassung |
| As high latitudes warm, vast stocks of carbon and nitrogen stored in
permafrost will become available for transport to aquatic ecosystems. While
there is a growing understanding of the potential effects of permafrost
collapse (thermokarst) on aquatic biogeochemical cycles, neither the spatial
extent nor temporal duration of these effects is known. To test hypotheses
concerning patterns and persistence of elemental export from upland
thermokarst, we sampled hydrologic outflow from 83 thermokarst features in
various stages of development across the North Slope of Alaska. We
hypothesized that an initial pulse of carbon and nutrients would be followed
by a period of elemental retention during feature recovery, and that the
duration of these stages would depend on feature morphology. Thermokarst
caused substantial increases in dissolved organic carbon and other solute
concentrations with a particularly large impact on inorganic nitrogen.
Magnitude and duration of thermokarst effects on water chemistry differed by
feature type and secondarily by landscape age. Most solutes returned to
undisturbed concentrations after feature stabilization, but elevated
dissolved carbon, inorganic nitrogen, and sulfate concentrations persisted
through stabilization for some feature types, suggesting that aquatic
disturbance by thermokarst for these solutes is long-lived. Dissolved
methane decreased by 90% for most feature types, potentially due to high
concentrations of sulfate and inorganic nitrogen. Spatial patterns of carbon
and nutrient export from thermokarst suggest that upland thermokarst may be
a dominant linkage transferring carbon and nutrients from terrestrial to
aquatic ecosystems as the Arctic warms. |
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