Some New Formalisms for Modelling the Interactions Between Plant Architecture, Competition and Carbo

Dynamical simulation models of tree growth and morphology were developed to address questions about the interrelations between tree structure, functions and environmental conditions on a mesoscale level. The modelling approach has a formal basis in stochastic growth grammars (i.e., extended L-systems), which can be interpreted by the software GROGRA (Growth Grammar Interpreter) yielding time series of attributed 3-D architectural structures representing trees. With appropriate extensions of this string rewriting language (sensitive functions, arithmetical-structural operators, local registers) it is possible to represent environmental control of shoot growth and some simple allocation strategies, and to reproduce typical competition eeects in tree stands qualitatively. The new GROGRA extensions which enable these results are completely documented.