Thinning Influence on the Modulus of Elasticity and Rupture in Eucalyptus grandis

Abstract

This article is focused on Eucalyptus grandis - main species of the genus planted in Uruguay for solid wood. The objective is to evaluate the impact of the intensity of thinning on modulus of elasticity (MOE) and modulus of rupture (MOR). The plantation analyzed is located in the department of Tacuarembó, and was planted on sandy soil in 1989, with seed from Bañado de Medina (Uruguay). The trial was designed with random plots with two replications and three treatments: A) intense thinning with 272 remaining trees / ha, B) medium thinning with 352 remaining trees / ha and C) un-thinned with 1280 remaining trees / ha. Thinning was conducted in 1994, when the forest was five years old, and assessments were made when the plantation was 19. From each treatment 10 individual trees were selected, with average diameter at breast height (DBH) in order to obtain defectfree specimens to be tested. The variables studied were the MOE and MOR of boards with commercial dimensions and defect-free specimens. There were no significant differences between treatments.