Effect of Age on Heartwood / Sapwood Relationship, Extractive Contente, and Permeability of Teak Wood

Abstract

Due to the physiological differences in the juvenile and adult phases of teak wood, differentiation occurs in the impregnation by extractive materials along the heartwood regions, assuming that there is also a significant variation in the permeability of this material. Thus, the study aimed to evaluate the influence of age on the heartwood / sapwood ratio (H/S), permeability, and extractives content of Tectona grandis L.f wood. Four ages (10, 12, 14, and 16 years) and four trees (repetitions) were evaluated, totaling 16 samples. The H/S ratio, extractive content, and wood permeability were determined, in addition to the average and maximum permeability among all ages selected for calculation of their porosity. The H/S ratio increased over the ages of 10 and 16, and the content of extractive materials increased until the age of 14. There was a high heterogeneity between the permeability values of the wood at all ages analyzed, and one of the possible explanations for this fact is the presence of tyloses in different places on the trunk and the arrangement of the pores around the growth rings.

Wood characterization of Tectona grandis L. F. cultivated in Brazil: a review of the last 30 years

“…The larger 7-year-old teak trees already have a higher relative percentage of heartwood than the smaller trees, nonetheless, the heartwood/sapwood ratio increased between the ages of 10 and 16 years old. (Benedetti, 2018, Canal et. al.…”

“…Teak also has low permeability to preservative solutions when subjected to pressure impregnation. Due to physiological differences between juvenile and adult wood, there are differences in the impregnation and permeability by extractive materials along the heartwood regions, and this is most likely due to the presence of tyloses in different locations in the trunk and the disposition of vessels around the growth rings (Canal et al, 2020).…”

“…Wood holocellulose content presents extreme commercial importance, as it constitutes a raw material for the manufacture of various products, such as cellulose, paper, ethanol, fabrics, in addition to countless other uses in the chemical and pharmaceutical industries (Chagas et al, 2014). The extractive content increases with the age of teak tree, up to the age of 14, and from this point onwards there is a trend towards stabilization (Canal et al, 2020). This increase in teak wood extractive content with tree age may be related to the wood natural durability, i.e, increasing the age, increases the proportion of heartwood, which contains more extractives.…”