A Review of the Factors Influencing Variations in the Heartwood Proportion for Solid Wood

Abstract

Using 146 journals, 6 chapters, 4 reports, 2 books, and a proceeding, this research seeks to investigate the factors that influence variations in the proportion of heartwood. The data were collected through an online search in databases such as Scopus, Science Citation Index, Science Direct, Google Scholar, and ResearchGate with seven search queries, namely heartwood variability, heartwood proportion, tree age of heartwood, growth rate of heartwood, silvicultural treatment of heartwood, as well as genetic and environmental effects of heartwood. By eliminating papers that were out of topic or title, purpose and year of publication, 67 journal articles, 4 chapters, 3 reports, a book, and a proceeding were selected. The review results showed that the amount of heartwood was influenced by its position in the tree, tree variations, such as age, growth rate, and species/genera, as well as the growing conditions, including location and environmental factors. It is also affected by various silvicultural treatments, namely spacing, thinning, pruning, fertilization, and irrigation. These findings indicate that the amount of heartwood is more controlled by the diameter of the wood than the age. Furthermore, several studies reported that the growth rate of sapwood rings was significantly higher than the heartwood rings, which can reduce the quality of solid wood used for construction. Therefore, it is necessary to control the proportion of heartwood through genetics and environmental factors, especially genetics, which has more effects on the growth rate of tree diameter than environmental factors. Previous studies revealed that tree diameter has a weak or negative correlation with other wood properties, such as basic density, color, and wood stiffness, which are generally important in global markets. It is important for breeders to concentrate on using species with superior genetic variations as well, especially the highly demanded traits in further studies.

Wood Quality of Young Tectona grandis L. f. Trees and Its Relationship with Genetic Material and Planting Site in Mato Grosso, Brazil

“…However, for the seminal material, the percentage of bark was statistically the same in This suggests that clonal plantations may be more advantageous by properly selecting superior genetic materials, providing higher percentages of heartwood even at intermediate ages. Considering the natural durability and attractiveness of coloration, heartwood constitutes a commercially valuable part of the teak stem [28,55,56]. Thus, teak trees with a greater percentage of heartwood have greater demand and appreciation.…”

“…Forests 2024, 15, x FOR PEER REVIEW 11 of heartwood constitutes a commercially valuable part of the teak stem [28,55,56]. Thus, te trees with a greater percentage of heartwood have greater demand and appreciation.…”

Macroscopic and Microscopic Anatomical Characteristics of Six Korean Oak Species

“…Additionally, Q. serrata, Q. mongolica, Q. dentata, Q. aliena, and Q. acutissima showed no significant differences in wood portions. Arisandi et al [22] reported that the heartwood proportion is directly influenced by tree variations (position in the tree, age, growth rate, and species), growing conditions (location and environmental factors), and silvicultural treatments (spacing, thinning, pruning, fertilization, and irrigation). Moreover, tree variations have a greater impact on the heartwood proportion than environmental conditions, and the heartwood proportion is more affected by wood species than age.…”