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Titel |
Modeling micro-topographic controls on boreal peatland hydrology and methane fluxes |
VerfasserIn |
F. Cresto Aleina, B. R. K. Runkle, T. Kleinen, L. Kutzbach, J. Schneider, V. Brovkin |
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. 19 ; Nr. 12, no. 19 (2015-10-08), S.5689-5704 |
Datensatznummer |
250118115
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Publikation (Nr.) |
copernicus.org/bg-12-5689-2015.pdf |
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Zusammenfassung |
Small-scale surface heterogeneities can influence land-atmosphere fluxes and
therefore carbon, water and energy budgets on a larger scale. This effect is
of particular relevance for high-latitude ecosystems, because of the great
amount of carbon stored in their soils. We introduce a novel
micro-topographic model, the Hummock-Hollow (HH) model, which explicitly
represents small-scale surface elevation changes. By computing the water
table at the small scale, and by coupling the model with a process-based
model for soil methane processes, we are able to model the effects of
micro-topography on hydrology and methane emissions in a typical boreal
peatland. In order to assess the effect of micro-topography on water the
balance and methane emissions of the peatland we compare two versions of the
model, one with a representation of micro-topography and a classical
single-bucket model version, and show that the temporal variability in the
model version with micro-topography performs better if compared with local
data. Accounting for micro-topography almost triples the cumulative methane
flux over the simulated time-slice. We found that the single-bucket model
underestimates methane emissions because of its poor performance in
representing hydrological dynamics. The HH model with micro-topography
captures the spatial dynamics of water and methane fluxes, being able to
identify the hotspots for methane emissions. The model also identifies a
critical scale (0.01 km2) which marks the minimal resolution for the
explicit representation of micro-topography in larger-scale models. |
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