 |
| Titel |
Modelling Seasonal Carbon Dynamics on Fen Peatlands |
| VerfasserIn |
Michael Giebels, Madlen Beyer, Jürgen Augustin, Mario Roppel, Radoszlav Juszczak, Tomasz Serba |
| Konferenz |
EGU General Assembly 2010
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250044177
|
|
|
|
|
|
| Zusammenfassung |
| In Germany more than 99 % of fens have lost their carbon and nutrient sink function due to
heavy drainage and agricultural land use especially during the last decades and thus resulted
in compression and heavy peat loss (CHARMAN 2002; JOOSTEN & CLARKE 2002;
SUCCOW & JOOSTEN 2001; AUGUSTIN et al. 1996; KUNTZE 1993). Therefore fen
peatlands play an important part (4-5 %) in the national anthropogenic trace gas
budget.
But only a small part of drained and agricultural used fens in NE Germany can be
restored. Knowledge of the influence of land use to trace gas exchange is important for
mitigation of the climate impact of the anthropogenic peatland use. We study carbon
exchanges between soil and atmosphere on several fen peatland use areas at different sites in
NE-Germany. Our research covers peatlands of supposed strongly climate forcing land use
(cornfield and intensive pasture) and of probably less forcing, alternative types (meadow and
extensive pasture) as well as rewetted (formerly drained) areas and near-natural sites like a
low-degraded fen and a wetted alder woodland. We measured trace gas fluxes with manual
and automatic chambers in periodic routines since spring 2007. The used chamber technique
bases on DROESLER (2005). In total we now do research at 22 sites situated in 5
different locations covering agricultural, varying states of rewetted and near-natural
treatments.
We present results of at least 2 years of measurements on our site of varying
types of agricultural land use. There we found significant differences in the annual
carbon balances depending on the genesis of the observed sites and the seasonal
dynamics. Annual balances were constructed by applying single respiration and
photosynthesis CO2 models for each measurement campaign. These models were based on
LLOYD-TAYLOR (1994) and Michaelis-Menten-Kinetics respectively. Crosswise comparison
of different site treatments combined with the seasonal environmental observations give
good hints for the identification of main flux driving parameters. Based on this
procedure we developed a specific methane efflux model, mainly driven by the observed
groundwater fluctuation and soil temperature. Depending on the observed timescale initial
starting points of the model showed up to be remarkably different. We also will
present suggestions for an advanced CO2 modelling as the present approaches are
both based on single parameters. Generally our experiences from our field studies
show that mono-parameterized models often fail in reproducing measured flux
values.
References:
Augustin, J., Merbach, W., Käding, H., Schnidt, W. & Schalitz, G. 1996. Lachgas- und
Methanemissionen aus degradierten Niedermoorstandorten Nordostdeutschlands unter dem
Einfluß unterschiedlicher Bewirtschaftung. Alfed-Wegener-Stiftung (ed.): Von den
Ressourcen zum Recycling: Geoanalytik-Geomanagement-Geoinformatik. Ernst & Sohn
Verlag. Berlin
Charman, D. 2002: Peatland and environmental change. John Wiley & Sons, LTD,
Chichester
Droesler, M. 2005. Trace Gas Exchange and climatic relevance of bog ecosystems,
Southern Germany, phD-thesis, TU München, München
Joosten, H. & Clarke, D. 2002: Wise use of mires and peatlands-background and
principles including a framework for decision-making. International Mire Conservation
Group and International Peat Society (eds.), Finland
Kuntze 1993: Moore als Senken und Quellen für C und N, Mitt. Deutsche Bodenkundliche
Gesellschaft 69, 277-280
Lloyd, J., Taylor, J. A. 1994. On the Temperature Dependence of Soil Respiration,
Functional Ecology, Vol. 8, No. 3, pp. 315-323
Succow, M. & Joosten, H. 2001: Landschaftsökologische Moorkunde, 2nd edition,
Schweizerbart’sche Verlagsbuchhandlung, Stuttgart |
|
|
|
|
|
|