A large variety of plant structure is deeply related to the strategy for growth and survival of species. However, a complex reality of plant structure was usually oversimplified in most of ecosystem simulation models. Thus, such models have their limits in simulating detail interactions between plant and environment. To refine and improve existing plant growth model, we developed a computer program to simulate 3-D structure of plant shoots and roots.

Basic structure units of plant shoot and branching patterns were analyzed using real plants. Obtained data are translated into L-system data format. Then, the 3-D structures of shoots were simulated using the program. The performance of the program was assessed by comparing the simulation outputs with real plants. Furthermore, for simulating basic structures of typical taproot and fibrous root systems, designing of L-system data template and selection of its parameters were conducted, respectively.

This L-system model simulated largely different structures of shoots and roots in different species fairly well in a same manner with different input data. However, the model simulates only geometry of plant structures, thus has its limitation in simulating some characteristic structures formed as a result of responses to environments in growth processes.