Effect Of Planting Spacing In Production And Permeability Of Heartwood And Sapwood Of Eucalyptus Wood

Abstract

The objective of this work was to evaluate the influence of different useful areas provided by the planting spacings (3 × 1, 3 × 2, 3 × 3, 3 × 4 m) on the production and permeability of heartwood and sapwood of Eucalyptus grandis and Eucalyptus grandis × Eucalyptus urophylla clones at 4 years old. Regardless of the clone, there was no effect of planting spacing on the heartwood/sapwood relation and wood permeability. All clones showed a heartwood decrease with increased height, regardless of planting spacing, and E. grandis (B) was the only one that had its heartwood percentage positively and significantly correlated with the dendrometric variables (DBH and commercial height). The use of the dymethil yellow compound was indispensable in defining the heartwood and sapwood regions in the samples from 50% of the stem height. The heartwood permeability was low in all evaluated clones, suggesting vessel obstruction by tyloses or other deposits, while sapwood permeability reached 405.4 cm3/cm.atm.s.

Water flow in different directions in Corymbia citriodora wood

“…The presence of tyloses clogging the vessels is one of the reasons that reduce the permeability of the wood in the heartwood (De Micco et al 2016, Helmling et al 2018. Higher permeability values of Eucalyptus wood in the sapwood region are reported in the literature (Silva et al 2010, Brito et al 2019.…”

“…The mean basic density of Corymbia citriodora wood equal to 647 kg/m 3 (Table 1) is consistent with the literature, for example, Zanuncio et al (2015) found values between 665 and 684 kg/m 3 for Corymbia citriodora wood from seven-years-old trees, and Monteiro et al (2018) report mean values of basic density for trees of the same species and age equal to 610 kg/m 3 . The comparison with the values of water flow in wood is more complex since few studies approach the rates of the free and absorbed water in a detailed way, as well as diverse methodologies, are used for measure permeability, for example, apparatus for testing the permeability to air and liquid in wood (Silva et al 2010, Tanaka et al 2010, Baraúna et al 2014, Rezende et al 2018, Brito et al 2019 and gravimetric techniques (Redman et al 2016, Thybring et al 2018.…”

“…However, the evaluation of the water flow in the wood in radial and tangential directions is complex when compared to the longitudinal axis, since their values are smaller, often imperceptible to the technique used for measurement. On the one hand, some studies record values for air and liquid permeability of hardwood only for the longitudinal axis (Silva et al 2010, Baraúna et al 2014, Rezende et al 2018, Brito et al 2019. On the other, Tanaka et al (2010) used the permeameter apparatus and ultrasonic treatment and found on Douglas-fir wood permeability higher values in the radial direction when compared to the tangential direction.…”

“…The relationship between water and wood has been scientifically studied for over a century, focusing mainly on softwoods (Engelund et al 2013). The greater importance of hardwoods in recent years, such as those from Corymbia genus, has led to increased studies on the water-wood relationship in these species (Zanuncio et al 2013, Zanuncio et al 2015, Redman et al 2016, Monteiro et al 2017, Monteiro et al 2018, Resende et al 2018, Rezende et al 2018, Brito et al 2019, Nascimento et al 2019.…”

“…Different techniques were used to evaluate water interaction with wood materials, including gravimetric techniques (Redman et al 2016, Thybring et al 2018 and apparatus for testing wood permeability to air and liquid (Silva et al 2010, Tanaka et al 2010, Baraúna et al 2014. However, different techniques to evaluate hardwood permeability have only found values for the longitudinal direction and have found difficulty in measuring this parameter in the radial and tangential axes (Silva et al 2010, Baraúna et al 2014, Rezende et al 2018, Brito et al 2019.…”