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| Titel |
Measurement and modelling of sap flow in maize plants |
| VerfasserIn |
Florian Heinlein, Christian Biernath, Peter Hoffmann, Christian Klein, Christoph Thieme, Eckart Priesack |
| 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 |
250090027
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| Publikation (Nr.) |
 EGU/EGU2014-4241.pdf |
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| Zusammenfassung |
| Climate change as well as the changing composition of the atmosphere will have an impact
on future yield of agricultural plants. In order to better estimate these impacts new,
mechanistic plant growth models are needed. These models should be able to dynamically
reproduce the plants’ reactions to modified climate state variables like temperature,
atmospheric CO2-concentration and water availability. In particular, to better describe
the crop response to more strongly changing water availability the simulation of
plant-internal water and solute transport processes in xylem and phloem needs to be
improved.
Our existing water transport model consists of two coupled 1-D Richards equations to
calculate water transport in the soil and in the plants. This model has already been
successfully applied to single Fagus sylvatica L. trees. At present it is adapted to agricultural
plants such as maize.
To simulate the water transport within the plants a representation of the flow paths, i.e.the
plant architecture, is required. Aboveground plant structures are obtained from terrestrial
laser scan (TLS) measurements at different development stages. These TLSs have
been executed at the lysimeter facilities of Helmholtz Zentrum München and at
the TERENO (Terrestrial Environmental Observatories) research farm Scheyern.
Additionally, an L-system model is used to simulate aboveground and belowground plant
architectures.
In a further step, the quality of the explicit water flow model has to be tested using
measurements. The Heat-Ratio-Method has been employed to directly measure sap flow in
larger maize plants during a two-months-period in summer 2013 with a resolution of 10
minutes and thus, the plants’ transpiration can be assessed. Water losses from the soil are
determined by measuring the weight of lysimeters. From this evapotranspiration can be
calculated.
Transpiration and evapotranspiration are also simulated by application of the modelling
system Expert-N. This framework allows for the combination of different models and
sub-models to simulate water, heat, nitrogen and carbon dynamics as well as crop
management and plant growth. A comparison between measured and modeled transpiration
and evapotranspiration is presented and discussed. |
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