Determinação do lenho juvenil através da variação radial do comprimento das fibras e determinação de propriedades físicas da madeira de Eucalyptus SP (Myrtaceae)

Abstract

Juvenile wood presents great differences in its anatomical characteristics and physical properties in relation to adult wood. This wood heterogeneity causes a series of inconveniences for the transformation and processing industry. The objective of this work was to study the fiber length and physical properties of juvenile and adult Eucalyptus sp. The tree was 48 years old, from the Campus of the Federal University of Recôncavo da Bahia located in the city of Cruz das Almas - BA. For this purpose, specimens with dimensions of approximately 25x25x50 mm were taken from transverse discs to determine the basic densities, total linear contractions and shrinkage coefficients of juvenile and mature wood. Samples were taken from these specimens to determine the fiber length of juvenile and adult wood. The result showed that the regions of mature wood compared with the regions of juvenile wood showed an increase in the values of basic densities; the tangential and radial total linear shrinkage values were higher for juvenile wood compared to mature wood, as well as the tangential and radial shrinkage coefficients; great variation in the lengths of the fibers present in the region considered as juvenile wood, while there is little variation in the lengths of the fibers in the region considered as mature wood. As a main conclusion, it was seen that based on the determination of fiber lengths, it was possible to determine different patterns for juvenile and adult wood, allowing the delimitation of of these regions.