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| Titel |
Isotopic Forced-Diffusion Technique for Soil Respiration Pathway Studies |
| VerfasserIn |
Nick Nickerson, Jocelyn Egan, David Risk, Gordon McArthur, Kevin Cunningham, Gloria Jacobson, Nabil Saad, Robert Panetta |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250084064
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| Zusammenfassung |
| Isotopic ratio measurements of soil-respired CO2Â can provide a wealth of insight into
soil-level carbon-cycle processes that is not available using bulk CO2Â emissions
measurements alone. Soil contains substantial amounts of carbon, and can contribute CO2to
the atmosphere through various respiration pathways. Isotopic analysis can distinguish
autotrophic root and rhizosphere respiration from heterotrophic respiration due to the
catabolism of soil organic matter (SOM). Because of this, researchers have shifted
their efforts toward the use of natural abundance and tracer isotopic techniques
in ecosystem respiration studies. However, recent experimental and theoretical
evidence indicates that these traditional techniques yield biased estimates of the soil
isotopic flux, largely owing to disturbances to the soil’s natural diffusive regime. To
help eliminate theses biases, we have developed a new technique called Isotopic
Forced-Diffusion (IsoFD). The Isotopic Forced-Diffusion technique integrates a
Forced Diffusion dynamic chamber with a cavity ringdown spectrometer measuring
δ13C-CO2, which are operated together as a closed, recycling system where the
leakage and pressures through the system are properly managed. The system produces
real-time, high temporal resolution isotopic soil efflux data. We will present the
theory behind this technique and present preliminary laboratory and field data. |
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