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Titel |
Annual CO2 budget and seasonal CO2 exchange signals at a high Arctic permafrost site on Spitsbergen, Svalbard archipelago |
VerfasserIn |
J. Lüers, S. Westermann, K. Piel, J. Boike |
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 ; 11, no. 22 ; Nr. 11, no. 22 (2014-11-24), S.6307-6322 |
Datensatznummer |
250117684
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Publikation (Nr.) |
copernicus.org/bg-11-6307-2014.pdf |
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Zusammenfassung |
The annual variability of CO2 exchange in most ecosystems is primarily
driven by the activities of plants and soil microorganisms. However, little
is known about the carbon balance and its controlling factors outside the
growing season in Arctic regions dominated by soil freeze/thaw processes,
long-lasting snow cover, and several months of darkness. This study presents
a complete annual cycle of the CO2 net ecosystem exchange (NEE) dynamics
for a high Arctic tundra area at the west coast of Svalbard based on
eddy covariance flux measurements. The annual cumulative CO2 budget is
close to 0 g C m−2 yr−1, but displays a strong
seasonal variability. Four major CO2 exchange seasons have been
identified. (1) During summer (snow-free ground), the CO2 exchange
occurs mainly as a result of biological activity, with a dominance of strong
CO2 assimilation by the ecosystem. (2) The autumn (snow-free ground or
partly snow-covered) is dominated by CO2 respiration as a result of
biological activity. (3) In winter and spring (snow-covered ground), low but
persistent CO2 release occurs, overlayed by considerable CO2
exchange events in both directions associated with high wind speed and
changes of air masses and atmospheric air pressure. (4) The snow melt season
(pattern of snow-free and snow-covered areas) is associated with both
meteorological and biological forcing, resulting in a carbon uptake by the
high Arctic ecosystem. Data related to this article are archived at http://doi.pangaea.de/10.1594/PANGAEA.809507. |
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