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| Titel |
Carbon dioxide balance of subarctic tundra from plot to regional scales |
| VerfasserIn |
M. E. Marushchak, I. Kiepe, C. Biasi, V. Elsakov, T. Friborg, T. Johansson, H. Soegaard, T. Virtanen, P. J. Martikainen |
| 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 ; 10, no. 1 ; Nr. 10, no. 1 (2013-01-24), S.437-452 |
| Datensatznummer |
250017481
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| Publikation (Nr.) |
 copernicus.org/bg-10-437-2013.pdf |
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| Zusammenfassung |
| We report here the carbon dioxide (CO2) budget of a 98.6 km2
subarctic tundra area in northeast European Russia based on measurements at
two different scales and two independent upscaling approaches. Plot-scale
measurements (chambers on terrestrial surfaces, gas gradient method and
bubble collectors on lakes) were carried out from July 2007 to October 2008.
The landscape-scale eddy covariance (EC) measurements covered the snow-free
period of 2008. The annual net ecosystem exchange (NEE) of different land cover
types ranged from −251 to 84 g C m−2. Leaf area index (LAI) was an
excellent predictor of the spatial variability in gross photosynthesis (GP),
NEE and ecosystem respiration (ER). The plot-scale CO2 fluxes were first
scaled up to the EC source area and then to the whole study area using two
data sets: a land cover classification and a LAI map, both based on field
data and a 2.4 m pixel-sized QuickBird satellite image. The good agreement of
the CO2 balances for the EC footprint based on the different measuring
techniques (−105 to −81 g C m−2 vs. −79 g C m−2;
growing season 2008) justified the integration of the plot-scale measurements
over the larger area. The regional CO2 balance based on area-integrated
plot-scale measurements was −41 or −79 g C m−2 yr−1
according to the two upscaling methods, the land cover classification and
the LAI map, respectively. Due to the heterogeneity of tundra, the effect of
climate change on CO2 uptake will vary strongly according to the land
cover type and, moreover, likely changes in their relative coverage in the future
will have great impact on the regional CO2 balance. |
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