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| Titel |
Soil respiration vs. soil CO2 efflux: the role of CO2 storage flux in soil respiration models |
| VerfasserIn |
Martin Maier, Helmer Schack-Kirchner, Hildebrand Ernst |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250043567
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| Zusammenfassung |
| Most studies implicitly consider soil surface efflux of CO2 to be the instantaneous soil
respiration, thereby neglecting possible changes in the amount of CO2 stored in the soil
pore-space. For the widely used chamber-based and micro-meteorological measurements,
filling or depletion of this CO2 pool can result in either an under- or overestimation of the soil
respiration. Soil temperature and moisture are the major abiotic factors controlling soil
respiration, and are used as explanatory variables by most models. However, these two factors
also influence soil gas transport, and thus, the amount of stored CO2. This effect can
add undesired noise to soil respiration models or even interfere with the model
parameters.
To examine the effect of CO2 storage flux, we monitored both the soil CO2 efflux and the
CO2 storage in the soil pore-space of a deep and well-aerated riparian soil. Measurements
were carried out from March 2009 to March 2010 using an automated chamber system and
CO2 concentration measurements at various depths (0.05 to 2.1 m) in the soil profile. First
results show that the integration of the storage flux can lead to a significant divergence of soil
respiration and soil CO2 efflux, potentially affecting respiration models. It will be discussed
whether the integration of the storage flux either changes the overall parameter
estimation or is only relevant to improve the understanding of particular meteorological
situations. |
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