GreenLab Course
Development
Factorisation
Foctorisation basis
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According to structural models, sets of similar organs are created for each growth cycle.
However, simulation models usually handle each of them individually, which may lead to cumbersome computation in the case of tree growth simulations, as the number of organs may exceed several million.
However, it is not usually necessary to consider local environmental conditions at organ level.
Thus, we can assume that all organs of the same kind, created during the same growth cycle, behave identically.
From a modelling point of view, it leads to a powerful structural factorization of the plant, based on botanical instantiations derived from the concept of physiological age.
Compact inductive equations of organogenesis can thus be deduced.
Arguments
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About sink organ Geometry
- Organ dimensions (internode lengths, diameter, leaf aera, etc. )
are assumed to be defined from functional modelling, resulting from the
organ biomass increase.
The biomass allocated is a ratio of the common biomass pool, defined by the organ sink strength divided by plant demand (the sum of all sink strengths).
This sink strength is related to organ maturity, and doest not depend on its position within the plant structure.
This applies for both structure geometry and structure topology.
About source organ geometry
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In GreenLab, biomass production modelling is based on the Beer-Lambert law,
thus light interception is evaluated by a simple global function.
It does not involve individual organs (leaf) or the orientations of groups of organs; the interception model considers the total leaf area for each growth cycle.
As a result, the geometrical and topological aspects of plant structure can thus be ignored.