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| Titel |
Does plasticity in plant physiological traits explain the rapid increase in water use efficiency? An ecohydrological modeling approach |
| VerfasserIn |
Theodoros Mastrotheodoros, Simone Fatichi, Christoforos Pappas, Peter Molnar, Paolo Burlando |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250127513
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| Publikation (Nr.) |
 EGU/EGU2016-7401.pdf |
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| Zusammenfassung |
| The rise of atmospheric CO2 concentration is expected to stimulate plant productivity by
enhancing photosynthesis and reducing stomatal conductance and thus increasing plant water
use efficiency (WUE) worldwide. An analysis of eddy covariance flux tower data from 21
forested ecosystems across the north hemisphere detected an unexpectedly large increase in
WUE (Keenan et al, 2013), which was six times larger than the increase found by most
previous studies based on controlled experiments (e.g., FACE), leaf-scale analyses, and
numerical modelling. This increase could be solely attributed to the increase in atmospheric
CO2 since other confounding factors were ruled out. Here, we investigate the potential
contribution of plant plasticity, reflected in the temporal adjustment of major plant
physiological traits, on changes in WUE using the ecohydrological model Tethys and Chloris
(T&C). We hypothesize that the increase in WUE can be attributed to small variations in
plant physiological traits, undetectable through observations, eventually triggered
by the atmospheric CO2 increase. Data from the 21 sites in the above mentioned
study are used to force the model. Simulation results with and without plasticity
in the physiological traits (i.e., model parameters in our numerical experiments)
are compared with the observed trends in WUE. We test several plant adaptation
strategies in being effective in explaining the observed increase in WUE using a
multifactorial numerical experiment in which we perturb in a systematic way selected plant
parameters.
Keenan, T. F., Hollinger, D. Y., Bohrer, G., Dragoni, D., Munger, J. W., Schmid, H. P.,
and Richardson, A. D. (2013). Increase in forest water-use efficiency as atmospheric carbon
dioxide concentrations rise. Nature, 499(7458), 324–7. |
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