FRACTAL CHARACTERIZATION OF ROOT-SYSTEM ARCHITECTURE

1. The fractal dimensions of seedling root systems of two grasses and two dicots growing in situ against glass sheets have been measured using the dividers method. Values were mostly below 1.5. 2. D was little affected by nutrient supply in Trifolium pratense, but differed significantly between four other species. 3. Values of D increased with age, slowly at first, then more rapidly and finally levelled off or declined slightly. This behaviour appears to correspond to the initial phase of radical branching pattern, which is then maintained. 4. D was negatively correlated with exterior link length and positively with topological index. 5. The fractal dimension appears to be a valuable additional index of the topology and geometry of root systems.