Mapeamento detalhado da variação radial da densidade básica da madeira de eucalyptus cloeziana e comparação da média aritmética simples e ponderada

Abstract

Wood basic density is one of the most important technological properties for characterizing forest raw materials, being directly related to mechanical performance, industrial yield, and the quality of wood-derived products. However, this property varies throughout the stem, especially in the radial direction, due to differences between juvenile and mature wood. In this context, the present study aimed to perform a detailed mapping of the radial variation in the basic density of Eucalyptus cloeziana wood and to compare estimates obtained using the simple arithmetic mean and the weighted mean based on the area represented by each sample within the disc. The study was conducted in an experimental stand approximately 15 years old, located at the IFMG – São João Evangelista Campus. Three trees representative of the stand's mean diameter were selected, and discs were collected at breast height (1.30 m). Sequential samples were then obtained along the entire radial profile at approximately 5 mm intervals. Basic density was determined as the ratio between oven-dry mass and saturated volume. The results showed a gradual increase in basic density from the pith to the bark in all evaluated trees, with minimum values close to 0.34 g cm⁻³ in the pith region and values to 0.70 g cm⁻³ in the outer regions, although values generally remained close to 0.60 g cm⁻³.The overall mean basic density obtained by the simple arithmetic mean was 0.498 g cm⁻³, whereas the weighted mean reached 0.555 g cm⁻³. It was concluded that the weighted mean provides more representative estimates of wood density, avoiding the underestimation observed when using the simple arithmetic mean. The average difference between the methods was approximately 57 kg m⁻³, a value that may significantly affect mass estimates and industrial planning when extrapolated to large volumes of wood.