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| Titel |
Stabilization Mechanisms of Soil Organic Matter in Eroding Watersheds: Implications for Erosion induced Terrestrial Carbon Sequestration |
| VerfasserIn |
Asmeret Asefaw Berhe, Margaret S. Torn, Jennifer W. Harden, Sarah D. Burton, Markus Kleber, John Harte |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250054131
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| Zusammenfassung |
| The terrestrial biosphere is dominated by sloping landscapes where biogeochemical cycling
of essential elements is controlled by the geomorphic, pedogenic, and ecological processes
that shape them. Soil organic matter (SOM) dynamics in such dynamic landscapes is greatly
influenced by process of soil erosion Here we determine the contribution of three classes of
stabilization mechanisms (physical isolation inside aggregates, chemical interaction with soil
minerals, and changes in molecular architecture of SOM) for protection of SOM from decay
in different types of eroding and depositional landform positions. We found that the
depositional positions have high C inventory, and are generally more effective in C
stabilization than the eroding positions. But, the effectiveness of different stabilization
mechanisms greatly depends on the nature of the landform positions considered. Our
findings show that protection of SOM by physical isolation inside aggregates and
chemical association of organic matter (OM) with soil minerals are more effective in
poorly drained depositional settings, compared to the well-aerated ones. Using
13C-NMR we showed that SOM in depositional settings is less transformed, better
preserved, than SOM in eroding landform positions. In this study, we demonstrate
that the nature of landform position where eroded SOM is deposited on exerts a
critical control on its stability and mechanisms of its stabilization post-deposition. |
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