The objective of the research was to use three different forms to calcuate the basic wood density of trees to obtain the estimate of dry mass and lignin mass of nine Eucalyptus wood species, at different ages. Three different forms were used to estimate the basic density of wood, at only one point on the trunk (1,3 m of height from the ground), the average weighted estimate by volume, and the arithmetical average. These estimates were used for the determination in the estimates of dry mass and lignin mass in the wood. The results showed the Eucalyptus grandis W. Hill., at four years of age, and the hybrid, at other ages were the species that highlighted in volumetric increment. The effects of species, age, and interaction species x age were significant for all the evaluated features. The effect of the estimate form was only significant for the basic density at ages five, six, and seven years. The hybrid was the only species that presented a difference in the forms of estimating basic wood density. Eucalyptus grandis and the hybrid were the species that highlighted in the production of dry mass and lignin, in spite of not being wood with the greater basic density and lignin content. The volumetric increment played an important role in the estimates of dry mass and lignin in the wood. So, it must be considered in all applications of wood that depend on these estimates.
Basic density; Wood; Eucalyptus
