Orange tree simulation under heterogeneous environment using agent-based model ORASIM

Abstract This paper presented an agent-based functional–structural model ORASIM for orange tree growth simulation. In ORASIM, detailed geometry, carbon/water acquisitions and expenses, as well as their dynamics are integrated into individual metamer/root agents. The nested-list of metamer/root agents forms a growing, three-dimensional orange tree structure. After model parameterization and validation using field data of orange tree growth, main features of tree functioning, i.e., morphological and physiological responses to environmental heterogeneity on different time scales have been investigated. It demonstrated that, using ORASIM, the phenotypic plasticity can be fully resulted from interactions between agents. Meanwhile, the output of ORASIM shows a good agreement for the characters of shape, branch pattern and other physiological features between the simulation and the real growth orange trees.