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| Titel |
Physically based model of organic carbon mineralization under varying soil environmental conditions |
| VerfasserIn |
Teamrat Ghezzehei, Chelsea Arnold, Asmeret Asefaw Berhe |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250108379
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| Publikation (Nr.) |
 EGU/EGU2015-8134.pdf |
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| Zusammenfassung |
| In recent years, it is increasingly becoming clear that soil encironmental conditions exert
significant control on the rate of organic matter mineralization. However, the exact
mechanistic coupling between hydrological and biogeochemical processes that govern the
rate of mineralization remains poorly understood. Here we present a modification of the
conventional exponential decay model of organic matter mineralization (dC/dt = -kC) by
incorporating the effects of water content and temperature. First, we redefine the
instantaneous labile carbon concentration term as accessibility of the bulk carbon to
decomposers. This in turn is related to water saturation (S); with the end members
being that all the carbon is accessible in saturated soil and none of the carbon is
accessible in completely dry soil (C / S). The decay constant is refined as a product of
several environmental and biogeochemical factors that regulate rate of mineralization
(k = kWkAkTkB..., where the W, A, T, and B denote water, oxygen, temperature, and
biology, respectively). This modeling framework is tested by comparison with a large set of
experimental data. One important advantage of this physically based model is that it can
be used to describe carbon mineralization rate under dynamic soil environmental
conditions (such as temperature and water content fluctuations). In addition, the model
accurately captures the complex mineralization pattern in aggregated soils that are
characterized by multiple classes of pores (e.g., inter- and intra-aggregate pores). |
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