Relationships among wood anatomy, hydraulic conductivity, density and shear parallel to the grain in the wood of 24-year-old Handroanthus vellosoi (Bignoniaceae)

Abstract

We studied the relationships among wood anatomy, hydraulic conductivity, density and shear parallel to the grain in the stem of Handroanthus vellosoi trees with the goal to identify possible trade-offs between hydraulic conductivity and mechanical properties. For this study we felled 12 trees with 24-year-old and cut 10-cm-thick disks at three heights: base of the trunk, one meter in height, and two meters in height. We propose that the relationship between hydraulic conductivity and mechanical resistance found along the H. vellosoi trunk indicates greater mechanical investment in the wood at the base of the trunk compared with the other two heights (1 and 2 meters). Anatomically, this would be represented by smaller diameter vessels and fibers with thicker walls. Consequently, strength investment implies lower water conductivity at the stem base. However, more studies are needed to determine whether this lower value with respect to 1 and 2 meters represents a significant effect on water transport along the stem. Key words: axial variation, biomechanics, brazilian wood, ipê amarelo, trade-offs. ResumoForam estudadas as relações entre anatomia da madeira, condutividade hidráulica, densidade aparente e cisalhamento paralelo à grã no tronco de árvores de Handroanthus vellosoi objetivando-se identificar os possíveis trade-offs entre a condutividade hidráulica e propriedades mecânicas. Para este estudo foram cortadas 12 árvores com 24 anos de idade, discos com 10 cm de espessura foram retirados em três alturas: base do tronco, um e dois metros de altura. Propomos que a relação entre a condutividade hidráulica e resistência mecânica encontrados ao longo do tronco H. vellosoi parece indicar um maior investimento mecânico na base do tronco em comparação com as outras duas alturas (1 e 2 metros), anatomicamente representada por vasos de menor diâmetro e fibras com paredes mais espessas. Consequentemente, um investimento em maior resistência mecânica implica em menor condutividade de água, contudo, mais estudos são necessários para determinar se este valor mais baixo em relação ao 1 e 2 metros representa um efeito significativo no transporte de água ao longo do tronco. Palavras-chave: variação axial, biomêcanica, madeira brasileira, ipê amarelo, trade-offs.Relationships among wood anatomy, hydraulic conductivity, density and shear parallel to the grain in the wood of 24-year-old Handroanthus vellosoi (Bignoniaceae)

Anatomical and physical properties of three lesser-known timber species from Malaysia

“…It was clearly shown from this present study that the anatomical properties which significantly influence the density are the fibre length, fibre wall thickness, vessel diameter, and number of vessels. This was also confirmed by previous studies by Martińez-Cabrera et al (2009), Toong et al (2014), andLongui et al (2017).…”

Wood Properties of 38-year-old Cariniana legalis (Mart.) Kuntze Based on Planting Spacing

“…The lowest vessel diameter and frequency were observed at the tree base (Figures 2a,2b,2c,and 2d). Similar results were found by Longui et al (2017), who reported on 24-year-old Handroanthus vellosoi trees. The vessel diameter was smaller at the base (91 µm), increasing significantly at 1 m (100 µm) and 2 m (106 µm) of stem height, and the vessel frequency was higher at 2 m (14 cells.mm -²) than that at 1 m (12 cells.mm -²).…”

“…The authors also found an inverse relationship between hydraulic conductivity and mechanical resistance. The presence of narrower vessels at the stem base, acting as a bottleneck, is a pattern observed in several species, with the purpose of increasing water transport by pressure differences along the vessel elements, thus improving their hydraulic efficiency (Assad et al, 2016) and/or meeting the mechanical demands concerning tree support (Sette Jr. et al, 2012;Longui et al, 2017). A decrease in vessel diameter tends to form denser wood, with greater mechanical resistance, since vessel lumens represent empty spaces that can weaken the wood in terms of its mechanical properties (Baas et al, 2004).…”

Longitudinal variation of wood basic density and anatomy of Curatella americana L

“…Vessel diameter tends to decrease with tree height, while vessel frequency increases (Table 3 and Figure 1). However, in 24-year-old Handroanthus vellosoi trees, it was found that the diameter of the vessels is smaller at the base of the tree, and greater at the heights of 1 and 2 m according to Longui et al (2017). Since the presence of narrower vessels at the base of the tree may be an indication of better efficiency in water transport due to pressure differences along the vessel elements (Assad et al, 2016) In this study, we also carried out correlations between basic density and anatomical features.…”