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| Titel |
Modeling climate change impacts on maize growth with the focus on plant internal water transport |
| VerfasserIn |
Florian Heinlein, Christian Biernath, Christian Klein, Christoph Thieme, Eckart Priesack |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250107250
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| Publikation (Nr.) |
 EGU/EGU2015-6945.pdf |
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| Zusammenfassung |
| Based on climate change experiments in chambers and on field measurements, the scientific
community expects regional and global changes of crop biomass production and yields. In
central Europe one major aspect of climate change is the shift of precipitation towards winter
months and the increase of extreme events, e.g. heat stress and heavy precipitation, during the
main growing season in summer. To understand water uptake, water use, and transpiration
rates by plants numerous crop models were developed. We tested the ability of two existing
canopy models (CERES-Maize and SPASS) embedded in the model environment
Expert-N5.0 to simulate the water balance, water use efficiency and crop growth.
Additionally, sap flow was measured using heat-ratio measurement devices at the
stem base of individual plants. The models were tested against data on soil water
contents, as well as on evaporation and transpiration rates of Maize plants, which
were grown on lysimeters at Helmholtz Zentrum München and in the field at the
research station Scheyern, Germany, in summer 2013 and 2014. We present the
simulation results and discuss observed shortcomings of the models. CERES-Maize and
SPASS could simulate the measured dynamics of xylem sap flow. However, these
models oversimplify plant water transport, and thus, cannot explain the underlying
mechanisms.
Therefore, to overcome these shortcomings, we additionally propose a new model, which
is based on two coupled 1-D Richards equations, describing explicitly the plant and soil water
transport. This model, which has previously successfully been applied to simulate
water flux of 94 individual beech trees of an old-grown forest, will lead to a more
mechanistic representation of the soil-plant-water-flow-continuum. This xylem
water flux model was now implemented into the crop model SPASS and adjusted to
simulate water flux of single maize plants. The modified version is presented and
explained. Basic model input requirements are the plant above- and below-ground
architectures. Shoot architectures were derived from terrestrial laser scanning. Root
architectures of Maize plants were generated using a simple L-system. Preliminary results
will be presented together with simulation results by CERES-Maize and SPASS. |
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