A static three-dimensional model of the Pinus tabulaeformis Carr.root system was developed by the fractal and pipe model assumptions.The model was constructed from the observations for topology

branching rules

link length and diameter and root orientation.Evaluation tests were carried out at the plant level.The test principally concerned the coefficients of α and q

where factor α is a ratio of the total cross-sectional area of a root before branching to that afterbranching

and the allocation parameter q defines the new link biomass after branching.Although they are independent of root diameter

the coefficients show some variability that may affect the precision of prediction.The model provides adequate predictions for dry root matter

total root length and root diameter at the plant level. The static model appears to be suitable for the root system of adult trees.Compared with other models

the main advantages of the fractal model are its plasticity and ease of use.