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| Titel |
Microbial respiration per unit microbial biomass depends on litter layer carbon-to-nitrogen ratio |
| VerfasserIn |
M. Spohn |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 3 ; Nr. 12, no. 3 (2015-02-10), S.817-823 |
| Datensatznummer |
250117806
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| Publikation (Nr.) |
 copernicus.org/bg-12-817-2015.pdf |
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| Zusammenfassung |
| Soil microbial respiration is a central process in the terrestrial carbon (C)
cycle. In this study, I tested the effect of the carbon-to-nitrogen (C:N)
ratio of soil litter layers on microbial respiration in absolute terms and
per unit microbial biomass C. For this purpose, a global data set on microbial
respiration per unit microbial biomass C – termed the metabolic quotient
(qCO2) – was compiled from literature data. It was found that qCO2 in the soil litter layers was positively correlated with the
litter C:N ratio and was negatively correlated with the litter nitrogen (N)
concentration. The positive relation between qCO2 and the litter
C:N ratio resulted from an increase in respiration with the C:N ratio
in combination with no significant effect of the litter C:N ratio on the
soil microbial biomass C concentration. The results suggest that soil
microorganisms respire more C both in absolute terms and per unit microbial
biomass C when decomposing N-poor substrate. The reasons for the observed
relationship between qCO2 and the litter layer C:N ratio could
be microbial N mining, overflow respiration or the inhibition of oxidative
enzymes at high N concentrations. In conclusion, the results show that qCO2 increases with the litter layer C:N ratio. Thus, the findings
indicate that atmospheric N deposition, leading to decreased litter C:N
ratios, might decrease microbial respiration in soils. |
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