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| Titel |
Erosion, deposition and replacement of soil organic carbon in Mediterranean catchments: a geomorphological, isotopic and land use change approach |
| VerfasserIn |
E. Nadeu, A. A. Berhe, J. Vente, C. Boix-Fayos |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 3 ; Nr. 9, no. 3 (2012-03-27), S.1099-1111 |
| Datensatznummer |
250006847
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| Publikation (Nr.) |
 copernicus.org/bg-9-1099-2012.pdf |
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| Zusammenfassung |
| Determination of whether soil erosion can constitute a net terrestrial
carbon dioxide (CO2) sink continues to suffer from lack of sufficient
focused studies and field data. Two of the major gaps in our understanding
of the erosion induced terrestrial carbon sink issue include rate of eroded
soil organic carbon replacement by production of new photosynthate and
stability of eroded organic carbon (OC) post deposition. Here we examined
the effect of erosion processes and land use change on the stock, type, and
stability of OC in two medium-sized subcatchments (18 and 50 ha in size) in
SE Spain. We analysed soil samples from drainage areas and depositional
settings for stock and isotopic composition of OC (14C and 13C),
and particle size distribution. In addition, we conducted land use change
analysis for the period 1956–2008 and a geomorphological survey of the
current erosion processes taking place in the slope-streambed connections.
Our findings demonstrate that land use change influenced the dominating
erosion processes and, thus, the source of eroding sediments. Carbon
isotopes used as tracers revealed that in one of the subcatchments the
deposited sediments were derived from deep soil (average Δ14C
of −271.5 ‰) through non-selective erosion processes and channel incision. In
the other subcatchment, topsoil material was predominantly eroded and the
average Δ14C in sediments was −64.2 ‰. Replacement of eroded
soil OC was taking place in the analysed soil profiles in the slopes
suggesting that erosion processes do not necessarily provoke a decrease in
soil OC stock over time. |
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