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| Titel |
The fate of carbon in floodplain sediments: A biogeochemical approach |
| VerfasserIn |
Danielle Alderson, Martin Evans, James Rothwell, Stephen Boult, Edward Rhodes |
| 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 |
250109793
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| Publikation (Nr.) |
 EGU/EGU2015-9732.pdf |
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| Zusammenfassung |
| Inland waters including fluvial systems and their associated sediments have been
predominantly overlooked as part of global carbon budgets until recently. In the UK,
peatlands are dynamically eroding, with the eventual result being ‘off-site’ greenhouse gas
emissions, which must be incorporated into carbon budgets for management strategies.
Evans et al. (2013) concluded fluvial systems are active cyclers of carbon, with
50-90% of particulate organic carbon (POC) exported from peatlands eventually
emitted as CO2. Floodplains, although commonly regarded as zones of carbon
storage, have been identified as potential hotspots of carbon cycling in the fluvial
system with a key process being decomposition of POC. Decomposition is known
to involve mass loss with selective transformation of labile compounds such as
polysaccharides, and preferential preservation of more resistant compounds (refractory
aromatics or aliphatics). Several decomposition proxies including FTIR band intensities,
hydrogen indices and C/N ratios, correlated with molecular structure determinations
using pyrolysis GC-MS, have been used successfully in peat cores (Biester et al.,
2013), to disentangle changes due to decomposition and those that are related to
vegetation variation. The aim of this research is to determine whether similar techniques
can be applied to arguably more complex systems such as floodplains, to examine
stratigraphic records of carbon cycling. Initial results from sediment cores taken
within a floodplain environment downstream of the Bleaklow Plateau in the Peak
District, UK will be presented. An initial OSL date of 640±90 years BP together with
assessment of the valley morphology using high resolution LiDAR DEM’s indicate
potential interaction of post glacial landslide features with the onset of substantial peat
erosion, conditioning the landscape to interrupt the transport of carbon down the
fluvial network. The floodplain under investigation is a potential hotspot for carbon
processing, thus representing an ideal study area for testing some of these ideas. |
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