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Teak is a famous commercial timber; however, many community forests produce low-quality teak from young trees. This research aimed to investigate the effect of heat treatment on the dimensional sta...

The objective of this study was to evaluate various physical and mechanical properties of experimental particleboard panels made from Asian giant bamboo (Dendrocalamus asper). Single layer panels having a density level of 0.75 g/cm3 from coarse and fine particles were used within the scope of this study. Thickness swelling, water absorption, surface roughness, and wettability characteristics of the samples were tested as physical properties while bending, internal bond strength, and screw withdrawal strength of the panels were considered for their mechanical properties. Resistance of the panels against termite and fungus were also determined. Based on the findings in the work both physical and mechanical properties of the panels made from coarse particles resulted in higher values than those made from fine particles with the exception of their internal bond strength. It appears that using fine particles in the panels enhanced their overall surface quality as well as wettability. Regarding biological deterioration of the samples, those made with coarse particles had better resistance. It seems that giant bamboo as a non-wood lignocellulosic species would have potential to be used as raw material to the manufacture value added particleboard with accepted characteristics.

Ebony (Diospyros celebica Bakh.) is an endemic plant on Celebes (Sulawesi) island. Extractive compounds within ebony wood cause it to have durability, strength, and beautiful patterns. In this study, we used near-infrared (NIR) spectroscopy to discriminate between ebony wood samples, based on their origins at different growth sites on Celebes island, and to develop quantitative models to predict the extractive content of ebony wood. A total of 45 wood meal samples from 11 sites located in West, Central, and South Celebes were collected in this study. NIR spectral data were acquired from hot water and ethanol&ndash, benzene soluble extracts from ebony wood in this study. The extractive content of the ebony was 10.408% and 10.774% based on hot water solubility and treatment with ethanol&ndash, benzene solvent, respectively. Multivariate analysis based on principal component analysis&ndash, discriminant analysis revealed that ebony wood from West Celebes differed from most of the wood from South Celebes, however, it was only slightly different from ebony wood from Central Celebes based on NIR spectra data. These findings were in line with the extractive contents obtained. Partial least square regression models based on wood meal spectra could potentially be used to estimate the hot water and ethanol&ndash, benzene extractive contents from ebony wood.

Gewang (Corypha utan Lamk.) is one of the endemic palm species which has been used as a building material for many years in Indonesia. The objective of this study was to enhance the overall resistance of gewang wood to biological deterioration by using smoke treatment. Samples taken from different parts of the trunks, namely bottom, middle, and upper parts in a longitudinal direction and outer and inner parts in a transversal direction, were exposed to the smoking process. Discoloration, dry-wood termite (Cryptotemes cynocephalus) and fungi (Schizophyllumcommune) resistance of smoked samples were determined according to the Indonesian standard. Based on the findings in this work, discoloration of smoked specimens was more prominent than that of the unsmoked samples. Overall termite and decay resistance of smoked samples were enhanced and higher than those of unsmoked samples without any influence of longitudinal and transversal orientations within the trunks. It appears that smoking can be considered as a potential method to improve decay and termite resistances of gewang wood.

Environmental conditions affect the natural weathering that leads to changes in wood characteristics. This study was conducted to evaluate physical and color changes and to predict changes in the mechanical properties of uncoated wood after outdoor exposure for 10 months (300 days). Five commercially important tropical wood species from Indonesia were used in field tests in this study, namely sengon or albizia (Paraserianthes falcataria), meranti or shorea (Shorea spp.), mahoni or mahagony (Swietenia spp.), teak (Tectona grandis), and merbau (Intsia spp.). Moisture content, wood density, and color change, as well as the ultrasonic wave velocity and dynamic modulus of elasticity, were evaluated every month. After 2 months of exposure (60 days), color totally changed (ΔE* > 12) for all species except merbau, which underwent changes in the fourth month (120 days). Wood became darker during the experimental period, with the exception of merbau wood, which became lighter by the end of 10 months. Shorea and teak were sensitive to color change as a function of the length of exposure. The wood species and length of exposure also significantly affected both ultrasonic wave velocity and dynamic modulus of elasticity.

Sengon, jabon, and acacia are fast-growing tropical wood species that are important for several wood industries in Indonesia. The purpose of this research was to evaluate the surface roughness and ...

Plantations of tropical species are becoming an increasingly important source of wood. However, it is important that research trials focus not only on tree growth performance, but also on wood quality. The aims of this study were to assess the growth performance of six commercially and ecologically important tree species from separate plantation trials in Indonesia and to determine the relationships between tree growth and wood quality in terms of the dynamic modulus of elasticity (MOE) and wood density. Forty-eight 7-year Maesopsis eminii Engl. and thirty-five 9-year specimens (7 each of 5 Shorea spp.) were selected from two trials. The MOE, based on acoustic velocity, was indirectly measured to evaluate wood stiffness. Tree-growth performance was evaluated, and correlations between growth traits and acoustic velocity as well as density and wood stiffness properties were estimated. The growth performance of M. eminii in terms of tree volume was significantly different in three different categories of growth (i.e. fast, medium, slow). Of the five Shorea spp. studied, Shorea leprosula Miq. had the highest growth rate, as expected since it is known to be a fast-growing Shorea species. Indirect measurement of wood quality by means of non-destructive ultrasonic methods showed a weak negative correlation between tree volume and acoustic velocity and dynamic MOE. Although each fast-growing tree could reach a merchantable size faster than other varieties or species, wood traits of various species tested were not significantly different based on tree growth rate performance. The findings from this study could be used to improve selection criteria in future breeding trials; indirect measurements of the dynamic modulus of elasticity can be used in mass pre-selection of genetic materials, to choose the most-promising material for in-depth evaluation.

Bearing strength largely affects the performance of wood connections. This study, determines the bearing strengths of six Indonesian tropical hardwoods with different specific gravities (ra...

Incense-resinous wood of agarwood is a high-value non-timber forest product found in the trunk or branches of Aquliaria and Gyrinops species. Incense-resinous wood of agarwood is formed as a response to tree damage caused by wounding or fungal attack. Detection of such wood in trees has generally been carried out based on natural signs such as dark spots or black marks when peeling back tree bark, but these often yield uncertain results. Sonic tomography can be applied to predict the presence of incense-resinous wood in standing trees. The objective of this study was to evaluate sonic tomography at various trunk heights based on variations in the sound velocity associated with the presence of incense-resinous wood. Ten agarwood trees ( Aquilaria malaccensis ) were selected for this study; five trees were artificially inoculated with Fusarium solani fungus and the other five were untreated. The results showed that the height of the measurement did not significantly affect the propagation velocity of sound waves or the tomographic results. Sonic tomography revealed that prediction of the deteriorated zone which is indicative of incense-resinous wood formation was 1.1% greater in inoculated trees than in uninoculated trees.

Adzkia U, Nugroho N, Siregar IZ, Karlinasari L. 2020. Ultrastructure of royal palm (Roystonea regia) leaf sheath. Biodiversitas 21: 967-974. The royal palm (Roystonea regia (Kunth) F.Cook is one of the palm species that are many planted along the streets as part of urban landscapes. As biologically products, in nature they can self-cleaning with drop off their big leaves. The study aims to examine the morphological characteristics of ultrastructure and elemental content, crystallinity, as well as fibers derivation characteristics from the royal palm. The samples were taken out from leaf sheaths that divided into three sections along the width of i.e. outside, middle, and inside; in two conditions of leaf sheaths namely green and brownish-dry. The morphology structure and elemental content were observed by the Scanning Electron Microscopy (SEM) and the Energy Dispersive X-ray analysis (EDX), while the crystallinity was analyzed using X-ray diffraction (XRD), and fiber characteristics were measured to determine cell dimensions as well as to calculate Runkle ratio (RR), muhlsteph ratio (MR), coefficient of rigidity (CR), felting powder (FP), and flexibility ratio (FR). The diameter of palm fiber bundles was decreased from outside towards inside. The model of vascular tissue was rounded which located in the central region of the fiber bundles. The silicon content in the inside section was lower than those in the middle and outside sections. It was in line with the degree of crystallinity in the inside section which that higher than other sections. The highest degree of crystallinity was about 18 %. The fiber length of royal palm leaf sheath was in values around 6000 μm. However, the royal palm leaf sheath had thick fiber walls and thin lumen, as well as other fiber derivation characteristics of muhlsteph ratio, the coefficient of rigidity and the flexibility ratio, were in low-quality values. For that reason, the study provides information that the royal palm sheath was recommended as a composite reinforcing material.

Anna N, Supriyanto, Karlinasari L, Sudrajat DJ, Siregar IZ. 2020. The growth, pilodyn penetration, and wood properties of 12 Neolamarckia cadamba provenances at 42 months old. Biodiversitas 21: 1091-1100. Jabon (Neolamarckia cadamba (Roxb) Bosser) is a potential tree species for the development of plantation forests and community forests to supply timber demands. Information on the growth characteristics and wood properties of N. cadamba is important for the present and future development, yet. Those data is not available. This study aimed to assess the variations on growth (height, diameter), pilodyn (Pilodyn®) penetration, and physical properties of wood from core sample; and characterize the wood properties of 12 N. cadamba provenances at Parung Panjang, Bogor. The assessment of growth characteristics, pilodyn penetration, and physical properties of wood from core sample was carried out through census (1030 trees) on all provenance (using non-destructive method). The wood properties analysis was carried out using destructive method to one sample for each of the 12 N. cadamba provenances. Growth characteristics observed were the height (numerical scale pole), diameter (calipers), and pilodyn penetration. Meanwhile, the wood properties consisted of wood density, specific gravity, moisture content, fiber length (light microscope), MFA (x-ray diffraction), MOE, and MOR. The results showed that the correlation between the height and moisture content with pilodyn penetration was weak and positive, while the correlation between diameter, wood density, and specific gravity was weak and negative. The result of non-destructive test showed that Gowa provenance is superior. The results of destructive tests to investigate the wood properties of the twelve provenances showed that Batu Licin provenance is superior in terms of specific gravity and MOE, while Gowa provenance is superior in terms of MOR and fiber length. The results of the wood properties (i.e. density, specific gravity, moisture content, MOE, MOR, MFA, and fiber length) of the 12 N. cadamba provenances showed that the woods can be potentially used as non-structural materials only.

Gaharu or agarwood or oudh is a fragrant and highly valuable nontimber forest product obtained from several species of trees that produce it in response to wounding or fungal attack. The aims of the study were to evaluate the sound wave velocity change from green to dry conditions in agarwood and tomographic images associated with changes in the moisture content. A total of 10 trees were selected for this study; five trees were artificially inoculated and the other five were left untreated. After in situ measurement of standing trees stem using nondestructive testing (PiCUS sonic tomography), air-dried disk samples from the trees were assessed. The results showed that sonic velocity values increase from 12% to 22% as moisture content decreases from a green condition (live tree) to an air-dried condition (disk sample). Nevertheless, solid and damage areas revealed only slight differences on the tomograms. This research combines traditional visual assessment with tomography to better detect the presence of agarwood in trees.