Radial and longitudinal variation of Araucaria angustifolia wood basic density for different ages

Abstract

The wood density is one of the most important property, and it is used as the main indicator for several types of use. However, this parameter can vary substantially along the stem, either in the bottom-top or pith-bark direction. Its determination becomes essential for the qualification of the wood of any forest species. This study aimed to evaluate the radial and axial variation the Araucaria angustifolia (Bert.) O. Kuntze wood density under different ages. Twelve trees with 23, 25, 28 and 30 years were felled. Discs were collected from 10%, 35%, 55% and 75% of tree height and another - from 1.3 m above ground level. From each disc three samples were taken from different positions in radial direction for density determination: near pith, central region and near bark. It was observed a reduction in density from bottom to top (longitudinal) and from pith-bark (radial). Older trees presented higher density values.