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| Titel |
Dynamics of shoot vs. root C assessed by natural 13C abundance of their biomarkers |
| VerfasserIn |
Mercedes Mendez-Millan, Marie-France Dignac, Cornelia Rumpel, Daniel P. Rasse, Sylvie Derenne |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250040419
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| Zusammenfassung |
| Cutins and suberins are biopolyesters that have been suggested to significantly
contribute to the stable pool of soil organic matter (SOM). They might be used as
tracers for the above- or belowground origin of plant material. The aim of this study
was to evaluate the dynamics of shoot and root-derived biomarkers in soils using a
wheat/maize (C3/C4) chronosequence. Our results suggest that α,Ï-alkanedioic acids
can be considered as root specific markers and mid-chain hydroxy acids as shoot
specific markers of wheat and maize in this agricultural soil. The changes of the
13C isotopic signatures of these markers with years of maize cropping after wheat
evidenced their contrasted behaviour in soil. After 12 years of maize cropping, shoot
markers present in soils probably originated from old C3 vegetation suggesting that
new maize cutin added to soils was mostly degraded within a year. The reasons for
long-term stabilisation of shoot biomarkers remain unclear. By contrast, maize root
markers were highly incorporated into SOM during the first six years of maize
crop, which suggested a selective preservation of root biomass when compared
to shoots, possibly due to physical protection. The contrasting distribution of the
plant-specific monomers in plants and soils might be explained by different chemical
mechanisms leading to selective degradation or stabilization of some biomarkers. |
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