Wood and bark fiber characteristics of Acacia melanoxylon and comparison to Eucalyptus globules

Abstract

Wood and bark fi bers of Acacia melanoxylon were characterized and compared to Eucalyptus globulus which is a major quality source of pulp fi bers. In 20 trees from four sites, fi ber length and wall thickness were measured at 5, 35 and 65% of total tree height and at 10, 30, 50, 70 and 90% of the distance from pith. Maceration were prepared in a 1:1 glacial acetic acid:hydrogen peroxide solution. Wood and bark fi ber length varied between 0.90 -0.96 mm and 1.33 -1.59 mm respectively. The cell wall thickness varied between 3.45 -3.89 μm in wood and 5.01 -5.40 μm in bark. Wood and bark fi ber length decreased from the bottom to the top of the tree and cell wall thickness had no specifi c pattern for axial variation. Fiber length and wall thickness increased from the pith to the bark, but the wall thickness increased slightly with some fl uctuations. In Acacia melanoxylon signifi cant site differences were found in relation to bark fi ber length and to wood wall thickness. The fi bers of Acacia melanoxylon were similar to those of Eucalyptus globulus but the wood fi bers were thinner and the bark fi bers thicker. The radial variation was similar in both species. In wood of Eucalyptus globulus, fi ber wall thickness increases from the base to the middle of tree height and decreases to the top; in the bark decreases from the base to the top. In Eucalyptus globulus fi bers bark are higher in the top.Key words: Xylem, phloem, cell biometry, acacia, eucalypts. COMPARAÇÃO DAS CARACTERÍSTICAS DAS FIBRAS

Evaluation on paper making potential of nine Eucalyptus species based on wood anatomical features

“…This radial pattern confirmed earlier reports on vessel area variation for E. globulus (Leal et al, 2007;Pereira et al, 2011;Ramírez et al, 2009;Tavares et al, 2011;Wilson et al, 1997Wilson et al, , 1998. The same radial pattern was also found in E. regnans (Dadswell, 1958), E. grandis (Taylor, 1973) and E. nitens (Mckimm and Ilic, 1987).…”

Characterization and within-tree variation of wood anatomy of Acacia melanoxylon

“…The latewood fibre wall thickness was always higher than that observed for earlywood. These values are lower than those observed by Tavares et al (2011) who measured the fibre wall thickness using dissociated samples. It is well known that fibre characteristics such as lumen width and wall thickness are important parameters for the wood raw-material in the pulp and paper industry.…”

“…The wood can be used for solid wood products (Griffin et al, 2011) in building and carpentry (Jablonski et al, 2010), panel products, pulp and paper (Santos el al., 2006(Santos el al., , 2012Anjos et al, 2011;Pereira et al, 2016) and food, fodder, poles and domestic fuelwood (Griffin et al, 2011). The anatomic characteristics are important for all applications, but there are not many reports on the wood anatomy of A. melanoxylon and on its variability (Iqbal, 1983;Sahri et al, 1993;Wilkins and Papassotiriou et al, 1989;Rodrigues et al, 2007;Tavares et al, 2011). The A. melanoxylon wood shows distinct growth rings with dense latewood bands, solitary or radial grouped vessels, vessel diameter between 100-300 m, low percentage of paratracheal parenchyma, homogeneous 1-3-seriate rays up to 40 cells high (Dadswell & Eckersley 1935;Wilkins and Papassotiriou et al, 1989).…”

Estimation of Acacia melanoxylon unbleached Kraft pulp brightness by NIR spectroscopy

“…melanoxylon was also the focus of research for the wood technological quality, e.g. wood volume (Rucha et al, 2011), heartwood variation (Knapic et al, 2006), basic density (Santos et al, 2012a;Igartúa & Monteoliva, 2009), wood macroscopic properties and fiber characteristics (Santos et al 2013;Tavares et al, 2011) and mechanical properties (Machado et al, 2014). A. melanoxylon is also interesting for pulping as evaluated by different authors regarding pulp yields and properties (Santos et al, 2012b;Lourenço et al, 2008;Santos et al 2007;Santos et al, 2006;Santos et al, 2005).…”