Quantifying shallow roots: tree geometry makes root research easy

A new method being developed for root research is described based on a fractal model. An equation was developed to derive the relation between total size of the root system and diameter of the proximal roots for 2 extreme branching patterns - dichotomous and herringbone. The protocol uses proximal root diameters and stem diameter at breast height to provide a tentative index of shallow rootedness (root competitiveness), tests for the fractal characteristics of root branching, and measurements of model parameters (internode lengths as a function of root diameter and the proportionality factor (alpha) between total cross-sectional surface areas, before and after branching). Preliminary tests of the method were done on 18 multipurpose trees on an acid ultisol in northern Lampung, Indonesia (mostly in a home garden, and about 6 yr old). Root data are given for these. The method is relevant to the study of competition between trees and crops in agroforestry systems. The original paper has been noticed separately in CABABSTRACTS.