Abstract

SEVERO, Elias Taylor Durgante; CALONEGO, Fred Willians  and  SANSIGOLO, Cláudio Angéli. Chemical Composition of Eucalyptus citriodora in Function of the Structural directions . Silva Lus. [online]. 2006, vol.14, n.1, pp.113-126. ISSN 0870-6352.

The aim of this work was to study the chemical composition of wood in the basis-top and pith-bark directions in Eucalyptus citriodora. Five trees were selected and discs collected at a height of 0,3m and every 4 m thereafter up to commercial height (corresponding to 12cm diameter). One wedge of each disc was removed for determination of the chemical analysis in the mature and juvenile wood. The results showed that: (1) In the basis-top direction the lignin and holocellulose content are constant in both the juvenile and mature wood. The extractive content in juvenile wood decreased up to the third log, though above this the contrary occurs. In mature wood there is a decrease in the extractive content with height; (2) In the pith-bark direction the lignin content is always higher in the juvenile wood in all the logs, although there was a significant difference in the first log. The holocellulose content was always smaller in the juvenile wood and showed a significant difference between juvenile and mature wood in the third and sixth logs. The extractive contents were smaller in the juvenile wood of the first and fourth logs, whereas a lower percentage of this component was shown in the mature wood of the remaining logs.

Keywords : holocellulose content; lignin content; extractives content; juvenile wood; Eucalypts citriodora.

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