Energy potential of wood from clones of Eucalyptus and Corymbia in different spacings

This study aimed to determine the influence of spacing and different genetic materials of Eucalyptus and Corymbia on wood production for energy purposes. At 24 months, two Eucalyptus clones (C1 and C2) and two Corymbia clones (C3 and C4) implanted in three different spacings (3.0 x 3.0, 3.0 x 1.5, and 3.0 x 1.0 m) were evaluated, totaling 12 treatments. In each treatment, 4 trees were selected, and 5 disks were removed from each tree, which were used to determine the basic density, the higher calorific value and to quantify the elemental carbon in the wood. Based on these characteristics, it was possible to estimate the dry mass, the carbon mass, and the amount of energy per hectare. It was observed that there was an effect of spacing, clone and interaction for the basic density of wood, being observed in clone C3 (C. citriodora x C. toreliana) the highest values of this property. As for the higher calorific value and the carbon content, no significant effect was found. It was also verified that the production of dry mass, carbon mass, and the amount of energy available per hectare increased with the densification of the spacings for all clones studied. The highest values of the amount of energy per hectare, in the different spacings, were attributed to clones C2 and C3 (3.0 x 3.0 m), clone C3 (3.0 x 1.5 m), and clones C1 and C3 (3.0 x 1.0 m). The C3 clone (Corymbia hybrid) can be a good alternative for energy use, due to its wood quality and productivity similar, or even superior, to Eucalyptus clones already used for this purpose.