Fractal geometery permits the description of many complex natural phenomena using a few relatively simple equations. At least three methods to generate fractal models have been developed to the degree that they can be applied to biological questions of ecological significance: fractal set theory, iterated function systems (IFS), and Lindenmayer systems (L- systems). Plant roots, fungi and soil pore spaces all have fractal properties; hence fractal methods appear to be suitable for the study of interactions between plant roots, the soil and soil microorganisms. The aim of the proposed research it to develop methods for modelling these interactions, to facilitate research into the plant root-soil ecosystem. Work in progress at the P.I.'s laboratory has shown the common species of soil fungi have patterns of mycelial branching that are fractal, and that these patterns can be modelled for up to 5 days after spore germination using L-systems. L-systems appear to work equally well for geometrically simple root systems, such as those of pea. These methods will be extended to other systems, and methods for modelling of the interaction between roots and soil microorganisms that are based on fractal representation will be developed. The methods will be tested by comparing them to laboratory measurements of fungus-root interactions. These type on interactions are broadly important in virtually all terrestrial environments, including many endangered habitats.
