Abstract
A quantitative analysis was done for the root system of Xylocarpus granatum with reference to the Pipe model theory of tree form proposed by Shinozaki et al. (1964a, b). For this objective, six root systems of X. granatum were excavated using a water-pump, and the roots were weighed for respective diameter categories. A significant allometric relationship between the squared stem-base diameter and the individual root weight was seen. The coefficient of this relationship was statistically regarded to be 1.0, meaning that the individual root weight is proportional to the squared value of stem-base diameter. We also analyzed the relationship between diameter and number of roots for the six sample trees. The number of roots with a given diameter and length was calculated from the weight and the specific gravity of roots. Significant linear relationships were recognized in this relationship for the six sample trees. For all sample trees, the coefficients of relationships were statistically regarded to be - 2.0. From these analyses based on population and individual level, we conclude that the root system of X. granatum obeys the pipe model. Application of this model is helpful in the estimation of root biomass, since individual root weight can be estimated from a proportional constant and the stem-base diameter of a mangrove tree.
