Introduction to the content

Structural-Functional Plant Models depict a combination between the architecture of plants (and of their development) and process-oriented components.
On the one hand, they allow the imaging of the three-dimensional structures of a plant and of its temporal change which is based on morphological units. On the other hand, functions like photosynthesis with a following assimilate transport can be modeled.
The growth of the structure depends then on the modeled processes – the functions.

Structural-Functional Plant Models are implemented in the course and in this learning module by the so called relational growth grammars which are a further development of Lindenmayer-Systems.
Lindenmayer-Systems (L-Systems) are formal grammars, which allow for example an efficient description of the temporal architectural development of a tree by simple rules. The tree is coded by a character string.
The relational growth grammars are a generalization of these rule systems. They are based on the replacement of graphs (instead of character strings) and increase the application possibilities of L-Systems by the diversity of graphs which consist of nodes and edges. Relational growth grammars allow the transformation of subgraphs of a graph with any number of edge-types (relations).

The programming language XL makes it possible to connect the object-oriented and imperative approach of the programming language JAVA with the rule-based approach of the Lindenmayer-Systems and the relational growth grammars.

The modeling platform GroIMP, which is able to interpret and compile the language XL, is used to create, execute and display the models.

The figures 1 and 2 (below) show examples of plant models which were created by relational growth grammars and GroIMP. For the beginning, these are just Structural Plant Models without integrated functions.

Many other examples which include the complete model code – also for other modelling-topics – are to be found at the page www.grogra.de.

You can find on the homepage of the course at www.uni-forst.gwdg.de/~wkurth/sm10_home.htm besides the script a detailed list of literature and links to web resources about this topic.