Variation of extractives content in heartwood and sapwood of Eucalyptus globulus trees

Abstract

The variation in extractives content in sapwood and heartwood was investigated among 12 trees in each of four commercial plantations of Eucalyptus globulus in central Portugal. The study was carried out at the 15% height level and extractions used successively dichloromethane, ethanol and water. At all sites, heartwood had significantly more extractives than sapwood, on average 3.8 and 2.4%, respectively. Most extractives consisted of ethanol soluble material (on average 52% of total extractives). Among the sites, there was a statistically significant difference in the content of extractives but the most important source of variation was the within-tree variation between sapwood and heartwood. Differences in the content of extractives were also observed among trees. A strong relation between extractives content and heartwood proportion was found. The potential loss of pulp yield and problems associated with accumulation of extractives are directly related to the heartwood proportion in the eucalypt stems. Forest management should take into account heartwood development and selection for minimising heartwood extractives.

Variation of Wood Pulping and Bleached Pulp Properties Along the Stem in Mature Eucalyptus globulus Trees

“…At the usual harvesting age for pulping, extractives content is lower, e.g., 2.9 % (Pereira 1988) or 3.5% (Miranda and Pereira 2001). Heartwood had significantly more extractives than sapwood, with 3.8 and 2.4%, respectively (Morais and Pereira 2012).…”

Química e colorimetria da madeira de Eucalyptus grandis W. Mill ex Maiden termorretificada

“…A redução dos extrativos a 170 °C se deve à volatilização dos extrativos polares, que são maioria nas folhosas e se decompõem em faixas de temperatura entre 130 e 250 o C (MIRANDA; PEREIRA, 2002;MÉSZÁROS et al, 2007;MORAIS;.…”

Effects of Pre-Freezing Prior to Drying upon Some Physical and Mechanical Properties of Eucalyptus urophylla × Eucalyptus grandis Wood

“…The extractives of eucalyptus wood contain alcohols, alkanes, esters, and acids (Zhang et al 2012). Generally, heartwood has significantly more extractives than sapwood in eucalyptus wood; these differences in the content of extractives are also dependent on the species and proportion of heartwood (Morais and Pereira 2011). Vanclay et al (2008) reported that heartwood color in Eucalyptus dunnii wood, especially its lightness, was correlated with tree size, and the large color differences between sapwood and heartwood may be correlated with high radial shrinkage.…”