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| Titel |
Tracing soil erosion impacts on soil organisms using 137Cs and soil nematodes |
| VerfasserIn |
Craig Baxter, John S. Rowan, Blair M. McKenzie, Roy Neilson |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250098389
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| Publikation (Nr.) |
 EGU/EGU2014-14060.pdf |
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| Zusammenfassung |
| The application of environmental radionuclides in soil tracing and erosion studies is now well
established in geomorphology. Sediment and erosion-tracing studies are undertaken for a
range of purposes in the earth sciences but until now few studies have used the technique to
answer biological questions. An experiment was undertaken to measure patterns of soil loss
and gain over 50 years, effectively calculating a field-scale sediment budget, to investigate
soil erosion relationships between physical and biological soil components. Soil nematodes
were identified as a model organism, a ubiquitous and abundant group sensitive to
disturbance and thus useful indicator taxa of biological and physico-chemical changes. A
field site was selected at the James Hutton Institute’s experimental Balruddery Farm in NE
Scotland. 10 metre-resolution topographical data was collected with differential GPS. Based
on these data, a regular 30 m-resolution sampling grid was constructed in ArcGIS, and a
field-sampling campaign undertaken. 104 soil cores (~50 cm-deep) were collected with a
percussion corer. Radio-caesium (137Cs) activity concentrations were measured
using high-purity germainum gamma-ray spectroscopy, and 137Cs areal activities
derived from these values. Organic matter content by loss on ignition and grain-size
distribution by laser granulometry were also measured. Additional samples were
collected to characterise the soil nematode community, both for abundance and
functional (trophic) composition using a combination of low-powered microscopy and
molecular identification techniques (dTRFLP). Results were analysed with ArcGIS
software using the Spatial Analyst package. Results show that spatial relationships
between physical, chemical and biological parameters were complex and interrelated.
Previous field management was found to influence these relationships. The results of
this experiment highlight the role that soil erosion processes play in medium-term
restructuring of the physico-chemical soil environment and the soil community. |
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