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| Titel |
Sudden cold temperature delays plant carbon transport and shifts allocation from growth to respiratory demand |
| VerfasserIn |
M. Barthel, E. Cieraad, A. Zakharova, J. E. Hunt |
| 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 ; 11, no. 5 ; Nr. 11, no. 5 (2014-03-14), S.1425-1433 |
| Datensatznummer |
250117279
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| Publikation (Nr.) |
 copernicus.org/bg-11-1425-2014.pdf |
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| Zusammenfassung |
Since substrates for respiration are supplied mainly by recent
photo-assimilates, there is a strong but time-lagged link between short-term
above- and belowground carbon (C) cycling. However, regulation of this
coupling by environmental variables is poorly understood. Whereas recent
studies focussed on the effect of drought and shading on the link between
above- and belowground short-term C cycling, the effect of temperature
remains unclear.
We used a 13CO2 pulse-chase labelling experiment to investigate the
effect of a sudden temperature change from 25 to 10 °C on
the short-term coupling between assimilatory C uptake and respiratory loss.
The study was done in the laboratory using two-month-old perennial rye-grass
plants (Lolium perenne L.). After label application, the δ13C
signal of respired shoot and root samples was analysed at regular
time intervals using laser spectroscopy. In addition, δ13C was
analysed in bulk root and shoot samples.
Cold temperature (10 °C) reduced the short-term coupling between
shoot and roots by delaying belowground transfer of recent assimilates and
its subsequent respiratory use, as indicated by the δ13C signal of
root respiration (δ13CRR). That is, the time lag from
the actual shoot labelling to the first appearance of the label in
13CRR was about 1.5 times longer under cold temperature.
Moreover, analysis of bulk shoot and root material revealed that plants at
cold temperature invest relatively more carbon into respiration compared to
growth or storage. While the whole plant C turnover increased under cold
temperature, the turnover time of the labile C pool decreased, probably
because less 13C is used for growth and/or storage. That is, (almost)
all recent C remained in the labile pool serving respiration under these
conditions. Overall, our results highlight the importance of temperature as a
driver of C transport and relative C allocation within the plant–soil system. |
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