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| Titel |
Annual carbon gas budget for a subarctic peatland, Northern Sweden |
| VerfasserIn |
K. Bäckstrand, P. M. Crill, M. Jackowicz-Korczyñski, M. Mastepanov, T. R. Christensen, D. Bastviken |
| 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 ; 7, no. 1 ; Nr. 7, no. 1 (2010-01-11), S.95-108 |
| Datensatznummer |
250004367
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| Publikation (Nr.) |
 copernicus.org/bg-7-95-2010.pdf |
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| Zusammenfassung |
| Temperatures in the Arctic regions are rising, thawing permafrost and
exposing previously stable soil organic carbon (OC) to decomposition. This
can result in northern latitude soils, which have accumulated large amounts
of OC potentially shifting from atmospheric C sinks to C sources with
positive feedback on climate warming. In this paper, we estimate the annual
net C gas balance (NCB) of the subarctic mire Stordalen, based on automatic
chamber measurements of CO2 and total hydrocarbon (THC; CH4 and
NMVOCs) exchange. We studied the dominant vegetation communities with
different moisture and permafrost characteristics; a dry Palsa underlain by
permafrost, an intermediate thaw site with Sphagnum spp. and a wet site with
Eriophorum spp. where the soil thaws completely. Whole year accumulated fluxes of
CO2 were estimated to 29.7, −35.3 and −34.9 gC m−2 respectively
for the Palsa, Sphagnum and Eriophorum sites (positive flux indicates an addition of C to the
atmospheric pool). The corresponding annual THC emissions were 0.5, 6.2 and
31.8 gC m−2 for the same sites. Therefore, the NCB for each of the
sites was 30.2, −29.1 and −3.1 gC m−2 respectively for the Palsa,
Sphagnum and Eriophorum site. On average, the whole mire was a CO2 sink of 2.6 gC m−2
and a THC source of 6.4 gC m−2 over a year. Consequently, the
mire was a net source of C to the atmosphere by 3.9 gC m−2 (based on
area weighted estimates for each of the three plant communities). Early and
late snow season efflux of CO2 and THC emphasize the importance of
winter measurements for complete annual C budgets. Decadal vegetation
changes at Stordalen indicate that both the productivity and the THC
emissions increased between 1970 and 2000. Considering the GWP100 of
CH4, the net radiative forcing on climate increased 21% over the
same time. In conclusion, reduced C compounds in these environments have
high importance for both the annual C balance and climate. |
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