PHYSICAL AND MECHANICAL PROPERTIES OF JUVENILE Schizolobium amazonicum WOOD

Abstract

Growth in world demand for wood implies a search for new fast growing species with silvicultural potential, and in this scenario for native species such as Paricá . Thus, the objective of this study was determining the physical and mechanical wood properties of the Schizolobium amazonicum species (known as Paricá in Brazil). Trees were collected from commercial plantations located in the north of Brazil with ages of 5, 7, 9 and 11 years. Four logs from trees of each age in the longitudinal direction of the trees were obtained, and later a diametrical plank of each log was taken to manufacture the specimens which were used to evaluate some physical and mechanical properties of the wood. The basic density of Paricá was reduced in the basetop direction and no difference between the radial positions was observed, while the average basic density of this wood was characterized as low. The region close to the bark showed less longitudinal contraction and also greater homogeneity of this property along the trunk, while for tangential contraction the smallest variation was found in the region near the pith. Paricá wood contraction was characterized as low. Age influenced most of the mechanical properties, where logs from the base had the highest values of mechanical strength.

Wood properties of Carapa guianensis from floodplain and upland forests in Eastern Amazonia, Brazil

“…C. guianensis does not present distinct growth rings 28 , what difficult the determination of its trees’ age by dendrochronology. Tree age influences the wood properties 29 , and thus this factor has potential to confound comparisons between floodplain and upland trees. The sampling by diameter class aimed to select individuals with similar diametric development to reduce the lack of knowing the tree age helping to maintain the sample standard.…”

Influence of Cambial Age and Axial Height on the Spatial Patterns of Xylem Traits in Catalpa bungei, a Ring-Porous Tree Species Native to China

“…This demonstrates that the cell turgor gradient affects cell elongations during cell differentiation, although the gradient might be rather small [68][69][70][71]. In general, a higher mechanical strength has been observed at the tree base in comparison to the tree top [72]. The elongation decline in most fibre-related traits along the axis, i.e., fibre length, fibre lumen diameter and fibre wall thickness to diameter ratio, is most likely adapted to the mechanical design of trees.…”

Propriedades físico-mecânicas da madeira sólida de Schizolobium amazonicum

“…Observa-se que a média geral da resistência ao cisalhamento (Tabela 2) é pouco inferior aos 5,9 MPa encontrado por Vidaurre et al (2018) para madeira de S. parahyba var. amazonicum na idade de 11 anos.…”

“…Para as demais propriedades avaliadas, tais como MOR e MOE à flexão estática e resistência à compressão paralela, os valores médios gerais foram superiores em 11,10%, 15,78% e 3,55%, respectivamente, ao registrado pelos referidos autores. Deve-se destacar que os valores das propriedades mecânicas encontradas no estudo de Vidaurre et al (2018) se deram a partir da avaliação de corpos de prova extraídos da primeira tora e que as propriedades mecânicas da madeira estiveram, no estudo da referida autora, dentre as que foram afetadas pela posição longitudinal do tronco, o que pode ter contribuído para a elevação dos valores médios registrados em relação aos observados para a madeira de S. parahyba var. amazonicum aos 14 anos no presente estudo.…”