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| Titel |
Changes in Flow and Transport Patterns in Fen Peat as a Result of Soil Degradation |
| VerfasserIn |
Haojie Liu, Manon Janssen, Bernd Lennartz |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250123605
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| Publikation (Nr.) |
 EGU/EGU2016-2890.pdf |
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| Zusammenfassung |
| The preferential movement of water and transport of substances play an important role
in soils and are not yet fully understood especially in degraded peat soils. In this
study, we aimed at deducing changes in flow and transport patterns in the course of
soil degradation as resulting from peat drainage, using titanium dioxide (TiO2)
as a dye tracer. The dye tracer experiments were conducted on columns of eight
types of differently degraded peat soils from three sites taken both in vertical and
horizontal directions. The titanium dioxide suspension (average particle size of 0.3 μm;
10 g l−1) was applied in a pulse of 40 mm to each soil core. Twenty-four hours
after the application of the tracer, cross sections of the soil cores were prepared for
photo documentation. In addition, the saturated hydraulic conductivity (Ks) was
determined. Preferential flow occurred in all investigated peat types. From the stained soil
structural elements, we concluded that undecomposed plant remains are the major
preferential flow pathways in less degraded peat. For more strongly degraded peat,
bio-pores, such as root and earthworm channels, operated as the major transport
domain. Results show that Ks and the effective pore network in less degraded peat
soils are anisotropic. With increasing peat degradation, the Ks and cross section
of effective pore network decreased. The results also indicate a strong positive
relationship between Ks and number of macropores as well as pore continuity. Hence,
we conclude that changes in flow and transport pathways as well as Ks with an
increasing peat degradation are due to the disintegration of the peat forming plant
material and decrement of number and continuity of macropores after drainage. |
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