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| Titel |
Nonlinear interactive effects of priming and temperature on soil organic matter decomposition |
| VerfasserIn |
Xingliang Xu, Na Qiao, Weixin Cheng, Douglas Schaefer |
| 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 |
250114732
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| Publikation (Nr.) |
 EGU/EGU2015-15545.pdf |
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| Zusammenfassung |
| Decomposition of soil organic matter (SOM) is sensitive to temperature and can cause
positive feedbacks to climate. Priming, the stimulation of SOM mineralization
induced by inputs of labile organic carbon (LOC), also affects SOM dynamics
and stocks and consequently may trigger positive climate feedbacks3. Therefore,
knowledge about how the interactions between priming and temperature affect SOM
decomposition is central to understanding the terrestrial carbon cycle. Here we
demonstrate that priming decreased with increasing temperature. Activation energy (Ea)
for SOM decomposition nonlinearly responded to increasing temperature. SOM
decomposition with higher LOC inputs showed higher Ea at low temperature, but lower
Ea at higher temperature compared to low or no glucose inputs. Low LOC input
reduced temperature sensitivity, while high LOC input strongly increased it. We
conclude that priming caused by high LOC availability magnified the effect of
increasing temperature on Ea at both the coolest and warmest temperatures while
the effect of increasing temperature on Ea was reduced or absent at lower LOC
availability. Therefore, greater LOC input via root exudates under future climate
conditions (e.g. by elevated CO2 or prolonged growing season) may accelerate SOM
decomposition in a non-linear fashion and cause positive feedbacks to atmospheric
CO2.
Key words: Activation energy, priming effect, temperature sensitivity |
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