Abstract:
The data for this research came from 137 plots with 600m2 of area, located in Pinus taeda stands, planted in the State of Paraná, with ages, ranging from 4 to 27 years old. The objectives wete to analyse the effect of age and site on the height-diameter relationship, and to search for the best number of pair of values height-diameter far fitting such relationship. The standard error of estimate, and the analysis of residuals were used as a criteria to select the best model to fit this relationship. The analysis of covariance revealed a greater influence, of age and site on the intercepts than on the slopes of the regression lines. The results showed also that 30 to 40 pairs of values are enough to fít the heigth-diamerer curve.