Using fractal analysis of root structure to identify the growth stage of plants

Previous research has found plant root structures to be scale invariant, a characteristic of many branching structures created by natural processes. Analysis has previously been performed on the root structure of mature plants to confirm their fractal behavior. However, how this fractal structure evolves in the early stages of plant growth has not been studied. Here, we image two species of plants—Maestro peas and Bush beans—over their first two weeks of life and calculate the fractal dimensions of 2d projections of their root structure. Our results show a rapid increase in fractal dimension in the first week of growth. We also find a distinct plateauing of the root’s fractal dimension when a plant exits the “seedling stage”. This behavior is consistent across both plant species studied, indicating that it may be universal and driven by common functional goals in the seedling stage of plants.