Influência do sítio na qualidade do lenho de árvores de Tectona grandis de plantações de rápido crescimento

• Ano de defesa: 2025
• Autor(a) principal: Hoffmann, Waldelaine Rodrigues
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso; Brasil; Faculdade de Engenharia Florestal (FENF); UFMT CUC - Cuiabá; Programa de Pós-Graduação em Ciências Florestais e Ambientais
• Palavras-chave em Português: Anéis de crescimento; Densidade do lenho; Condições de crescimento; Variação radial e longitudinal; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL; Growth rings; Wood density; Growth conditions; Radial and longitudinal variation
• Link de acesso: http://ri.ufmt.br/handle/1/7190

Teak plantations account for approximately 80% of the wood supply on the market, with a significant portion originating from fast-growing forests. However, fast-growing teak is still commonly associated with lower-quality wood. Furthermore, factors such as site, age, and position along the stem affect wood density, making it necessary to assess how these factors influence the radial and longitudinal variation of basic density and growth ring width. The objective of this study was to evaluate the influence of planting site on the apparent wood density profile of 15–16-year-old Tectona grandis from fast-growing plantations, using X-ray microdensitometry. The radial and longitudinal variation of growth ring width, basic wood density, and the width and density of earlywood and latewood were also evaluated in the first three commercial logs. The study sampled 18 trees from 15- to 16-year-old commercial teak plantations located in the states of Mato Grosso and Pará, Brazil. Discs were collected at four heights, corresponding to the base (0.1 m) and up to the top of the first three commercial logs (2.7 m, 5.4 m, and 8.1 m). The wood density profile demonstrated that the material from Mato Grosso presented greater radial variation in density. Regardless of the site, the ring width decreased in the radial direction and was larger at the tree base, reducing from the base (0.1 m) to a height of 8.1 m by 36.4% in Mato Grosso and 22.4% in Pará. In both sites, the earlywood width decreased longitudinally, averaging 10 mm in the Pará site and 9.19 mm in Mato Grosso, while the latewood width remained constant regardless of height. Trees from Pará showed an average latewood width of 0.37 mm, a value higher than that observed in the teak from Mato Grosso (0.33 mm). The wood density of teak trees from the Mato Grosso site was lower (0.571 g/cm³) than that from the Pará site, which reached 0.628 g/cm³. The density also increased in the radial direction and decreased with less intensity in the longitudinal direction. There was no significant relationship between growth ring width and density. It is concluded that edaphoclimatic conditions influenced tree development, reflecting in radial and longitudinal variations in the characteristics of growth ring width, earlywood and latewood width and density, and the wood density of Tectona grandis. Trees from the Pará site presented higher density and radial homogeneity, whereas teak trees from Mato Grosso showed less longitudinal variation. Both sites presented trees with satisfactory teak wood density compatible with commercial standards, demonstrating that the fast growth of the trees did not compromise the material's quality.