THE BASIC AXIAL VARIATION OF SEVEN YEAR OLD Acacia mangium WILLD WOOD

Abstract

From a seven year old population of acacia mangium, discs were taken from the trunks of 126 trees in order to study the species’ basic density. The basic average density (DBM) found was between 0.524 + 0.076 g/cm3. The axial variation for the basic density (Db), explained according to a quadratic model (R2 = 0.83), revealed a reduction tendency of up to half of the trunk’s height, increasing from this point up to the top without reaching the Db’s value for the base. The linear model was what best explained the relation between the DBM and the Db, obtained at various positions along the trunk. In fact, this relation was even more accentuated (R2 = 0.81) at 25% of the trunk’s height. Thus, in the determining of the species’ DBM through destructive methods, samples taken at 25% of the trunk’s height can be used. Nevertheless, for non-destructive samples, the height of 25%, may be too much, and so, withdrawing a sample, using an Pressler’s cork bore, for example, may not be feasible. In this case, withdrawing from the DAP is suggested because the relation at this height is also high (0.78).

Keywords

• <i>Acacia mangium</i>
• densidade básica média
• variação axial da densidade.