The data analysis of variance (Table 3) showed that
height level in the tree is a significant factor of variation,
although explaining only 8.3 % of the total variation, while
sites showed no statistically significant influence on the
variation of density. Most of the variation was included in
the residue (91.7 %) and refers to the between-tree variability,
and to other factors not considered in this study.
Figure 1 illustrates the wood-density profile along the
stem, revealing not only a high variability but also a clear
trend.