This research aimed to determine the basic density, the estimate of dry mass and the chemical composition of clones and Eucalyptus species. Four clones and five species of Eucalyptus were appraised, with four years old, coming from the RIMA Industrial Company S.A. Five trees were sampled for clone and species in three and four diametric classes, respectively. Wood characteristics as the basic density, the insoluble and soluble lignin in acid sulfuric, extractive total and ash content in the wood were available. The results showed that the volume, with or without bark, and estimated dry mass showed significant effects of genetic material (clone and species) and diameter class. The lignin content was not significantly influenced by both genetic material and diameter class. Wood basic density had a significant effect of diameter class for clones and genetic material for the species. The identity test for linear models was only not significant for estimated dry mass of the species, indicating to be possible to use the common equation independent of the species. The clones showed a more homogeneous wood with lower average basic density, extractives and total lignin content and higher holocellulose content, characteristics which are suitable for pulp production. The wood species showed more heterogeneous with highest average basic density, estimated dry weight, total lignin and extractives content and lower ash and holocellulose content, characteristics desirable for bioenergy production
quality; young wood; eucalypts
