Lina Karlinasari

Growth stresses in old beech poles after thinning: distribution and relation with wood anatomy

In the present study, we investigated the reaction of small diameter but old beech poles to canopy opening with particular interest in occurrence of growth stresses which allows the tree to maintain or correct its spatial position. We studied the relationships between growth stresses and (i) thinning treatment and (ii) anatomical structure. Forty-two beech poles were used for the study, half of which were thinned in 2007. We measured the growth stresses indicators (GSI) at eight positions around the trunk periphery and wood anatomical characteristics including proportion of G-fibers and vessel characteristics. Surprisingly, thinning treatment did not affect the average growth stress level and intensity of reaction in old beech poles. This rather unexpected result may be related to the high age of these trees and/or the high reaction wood occurrence prior to thinning resulting from the growth in suppressed condition. Considering the relationship between the proportions of G-fiber and the level of growth stresses, a significant positive correlation was found in agreement with previous studies on other species. Further, a negative correlation was found between vessel surface area and GSI level. Vessel frequency was also decreasing with the increasing GSI level and proportion of G-fibers.

Tree growth performance and estimation of wood quality in plantation trials for Maesopsis eminii and Shorea spp.

AbstractPlantations 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.

Evaluation of surface roughness and wettability of heat-treated, fast-growing tropical wood species sengon (Paraserianthes falcataria (L.) I.C.Nielsen), jabon (Anthocephalus cadamba (Roxb.) Miq), and acacia (Acacia mangium Willd.)

ABSTRACT 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 wettability of some heat-treated, fast-growing Indonesian wood species. Surface roughness was evaluated using the mean arithmetic deviation of the profile (Ra), whereas wettability was determined by measuring the contact angle method. The wood was subjected to heat treatment at 120, 150, or 180°C for 2 or 6 h using a small kiln unit. The heat treatment modification reduced the moisture content, wood density, and surface roughness and increased the wettability properties of all wood species. Jabon wood was the smoothest, followed by acacia and sengon, whereas jabon had the lowest wettability, followed by acacia and sengon. Wood anatomy has influences on those properties tested. Heat treatment did not affect surface quality but revealed a significant difference in wettability properties.

Bolt-bearing strength and its relationship to mechanical properties of wood, evaluated in six Indonesian tropical hardwoods

ABSTRACT Bearing strength largely affects the performance of wood connections. This study, determines the bearing strengths of six Indonesian tropical hardwoods with different specific gravities (ranging from 0.43 to 0.84) by half-hole testing. The results for three bolt diameters were compared to the bearing strengths in the Indonesian National Standard (SNI) and the National Design Specification (NDS) for Wood Construction. Next, the bolt-bearing strengths were related to the specific gravities and mechanical properties of the woods. With increasing specific gravity, the bearing strength increased from 26 to 70 MPa. The experimentally obtained bearing strengths of light and heavy red meranti, mersawa, kapur and bangkirai woods were 3–15% and 11–23% lower than the SNI and NDS values, respectively. In contrast, the experimental result for merbau was 23 and 11% higher than the SNI and NDS values, respectively. The bearing strength most closely approached the compression strength parallel to the grain.

Acoustic-Based Technology for Agarwood Detection in Aquilaria Trees

Agarwood is a non-timber forest product with high economic value. This incense wood is produced in the living stem of Aquilaria tree species after exposure to several stress factors and is not profoundly visible. Traditionally, agarwood hunters or collectors predict the existence of agarwood in the tree by relying on their visual assessment and experience, which may not be accurate at all times. To overcome this uncertainty, new technologies such as the nondestructive testing (NDT) technology are more reliable at providing valuable information for managing an agarwood plantation. In this study, an acoustic-based NDT has been applied on wounded and inoculated Aquilaria trees from which a reduction in sound velocity has been recorded. When coupled with PiCUS® sonic tomograph device, the tomogram results displayed progressing stages of decays consistent with that caused by fungal attack. The technology has been successful in detecting the existence of the agarwood in the target tree and can be improved for estimating the quantity and quality of agarwood in live trees periodically, before the final harvesting.

Penggunaan Pot Berbahan Dasar Organik untuk PembibitanGmelina arborea Roxb. di Persemaian

The objectve of this research was to obtain the best materials composition and adhesive of organic pot for forest trees seedling production. Organic pot strength was evaluated by testing the strength of rupture elasticity and elasticity stiffness of each composition. The bioassay testing used Completely Randomized Design with factorial pattern, consisting of two factors, (1) basic raw materials of the pot (used newspaper, litter and compost) and (2) the type of adhesive (control, tanin and starch). The results showed that the adhesive starch gave higher strength, whereas adhesive tannin gave higher stiffness as compared to control. Results of bioassay showed that the mixture (50:50 v/v) of basic materials of used newspaper and compost (KKK) which were glued with tannin, produced the best results for height and diameter increament with the value of 35.85 cm, 0.31 cm respectively and biomass value of 0.99 g after 12 weeks of planting. The highest level of damage in organic pot with basic raw materials KKK without adhesive was 47.6%, whereas lowest level of damage in organic pot with basic raw material used newspaper (KK) with tannin addhesive was 2.0% after 12 weeks in the nursery. Keywords: adhesive, Gmelina arborea,organic pot, organic matter, nursery,