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| Titel |
The intraspecific variability of short- and long-term carbon allocation, turnover and fluxes under different environmental conditions |
| VerfasserIn |
Frederik Wegener, Wolfram Beyschlag, Christiane Werner |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250095113
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| Publikation (Nr.) |
 EGU/EGU2014-10555.pdf |
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| Zusammenfassung |
| Carbon allocation strategies differ clearly between functional plant groups (e.g. grasses,
shrubs and trees) and to a lesser extent between different species of the same functional
group. However, little is known about the plasticity of carbon allocation within the same
species.
To investigate the variability of carbon (C) allocation, we induced different allocation
pattern in the Mediterranean shrub Halimium halimifolium by changing growing
conditions (light and nutrition) and followed the plant development for 15 months. We
analyzed morphological and physiological traits, and changes in C allocation and
δ13C values in seven tissue classes: 1st generation leaves, 2nd generation leaves,
emerging leaves, lateral shoots, stem, main roots and fine roots. We used a soil/canopy
chamber system that enables independent measurements of above and belowground
δ13CO2-exchange, enabling total estimates of carbon gain during photosynthesis and the
carbon loss during respiration on a whole plant level. Moreover, we followed the fate
of recently assimilated carbon in all plant tissues by 13CO2 pulse labeling for 13
days.
A reduction of light (Low L treatment) increased allocation to stems by 84% and the
specific leaf area (SLA) by 29%, compared to control. Reduced nutrient availability (Low N
treatment) enhanced carbon allocation into fine roots by 57%. We found high intraspecific
variability in turnover times of C pools. The Low N treatment enhanced transport of recently
assimilated C from leaves to roots in quantity (22% compared to 7% in control plants) and
velocity (13C peak in main roots after 5h compared to 18h in control). The treatments
differed also in fractions of 13C recovered within leaves: 48%, 28% and 41% of 13C
from labeling were found after 13 days in leaves of control, Low N, and Low L,
respectively.
Through the combination of natural carbon isotope analysis, 13CO2 labeling and
whole-plant chamber measurements we obtained information about long and short-term C
allocation to different tissues and respiration. The results give valuable new information to
understand the total plant C balance and to characterize its intraspecific variability due to
environmental factors. |
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