Density of Araucaria angustifolia wood from overstocked stand

Abstract

The aim of this work was to evaluate the radial and longitudinal variations of wood specific gravity in an overstocked stand of Araucaria angustifolia, with 65 years. The stand was located in the National Forest of Açungui, Campo Largo, Parana State, Brazil, with thinning recorded between 1970 and 1980, without subsequent thinnings. We selected three trees for each diameter class: 10-30 cm, 30-50 cm and 50-70 cm. To the longitudinal analysis, we collected discs from seven heights (0, 20, 40, 60, 80 and 100% of commercial stem and at 1.3 m). The barks were removed and it was obtained opposite wedges until pith and five samples were taken in radial direction from each disk. In general, there was an increase of wood specific gravity in radial direction. The average differed significantly along the stem, with decreasing trend of wood specific gravity in the longitudinal direction. However, average specific gravity at 60% of commercial height was higher than at 40%, than reducing to the top, indicating effect of competition that occurred in the area. The no uniform wood along stem indicates negative effects of the lack of management in the stand.