COMPARATIVE ANALYSIS OF FOREST PLANTATIONS CUTTING AGE BASED ON VOLUMETRIC AND GRAVIMETRIC UNITS.

The objective of this work was to evaluate the technical and economic cutting age of forest plantations considering the wood market under volumetric and gravimetric measurement units. Volumetric production and wood basic density for Eucalyptus urophylla clones stands were obtained from a forest company in the Jequitinhonha's region, Minas Gerais State, for ages of 3 to 9 years. It was estimated: mass per hectare; technical cutting age (TCA) for volume and mass; and economic viability at different interest rates. Data was divided by three clones, being the denser (C), passing through (B) median density, and less denser (A). The results showed that in alternating volumetric for gravimetric unit, the TCA occurs at least one year later. For the economic analysis, the results demonstrated that projects for wood commercialization by gravimetric measurement are economically viable when using high-density clones, due to the higher amount of mass per volume. For clones with low density and high volumetric productivity, the analysis must be done from a volumetric point of view, as the economic results were 23% higher than in the mass analysis. It was concluded that the adoption of the gravimetric unit of measure in the forest sector tends to cause significant changes in project management, improving wood characteristics for energy by postponing the cutting age and making more sensible the genetic material selection. [ABSTRACT FROM AUTHOR]