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Modeling micro-topographic controls on boreal peatland hydrology and methane fluxes.
- Source :
- Biogeosciences Discussions; 2015, Vol. 12 Issue 24, p10195-10232, 38p, 1 Diagram, 1 Chart, 7 Graphs
- Publication Year :
- 2015
-
Abstract
- Small-scale surface heterogeneities can influence land-atmosphere fluxes and therefore carbon, water and energy budgets on 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 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 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. [ABSTRACT FROM AUTHOR]
- Subjects :
- PEATLAND ecology
TOPOGRAPHY
METHANE
WATER balance (Hydrology)
GEOLOGIC hot spots
Subjects
Details
- Language :
- English
- ISSN :
- 18106277
- Volume :
- 12
- Issue :
- 24
- Database :
- Complementary Index
- Journal :
- Biogeosciences Discussions
- Publication Type :
- Academic Journal
- Accession number :
- 112185329
- Full Text :
- https://doi.org/10.5194/bgd-12-10195-2015