Figure 1. Conceptual scheme of the functional-structural tree model coupled with soil water balance for Mongolian Scots pines: the seed gives the initial pool of biomass, which is used to build organs (internodes, leaves) and thus the plant architecture.

The seedlings take up water from soil for leaf transpiration and biomass production during each growth cycle. The biomass produced is a product of the amount of water transpired by plant and water-use efficiency (WUE). The biomass is stored in the common pool of reserves and is then distributed among organs, which ends the growth cycle. The plant topology, which deals with the physical connections between plant components, is constructed based on automaton rules at the organ scale. Plant architecture can be constructed by topological and geometric information, which includes the shape, size, orientation and spatial location of the components.