Moisture Content in Drying Wood Using Direct Scanning Gamma-Ray Densitometry

The distribution of moisture content in specimens of Eucalyptus regnans at various stages of drying from the green state has been measured using a direct scanning gamma-ray densitometer. Densitometry results obtained using 59.5 keV gamma-ray photons were compared with data obtained from matched specimens using a conventional slicing and weighing technique. Preliminary results of a shrinkage distribution analysis are presented for the first time. A detailed discussion of the theoretical and experimental aspects of the scanning densitometry technique is given together with a description of the instrument constructed for this work

Wood Permeability Assessment of Young Teak (Tectona grandis L.f.)

Wood properties of young teak (Tectona grandis L.f.) is inferior, and then preservative treatment is one possible solution to enhance its service life. The uptake and movement of preservatives through wood cell structure is directly connected to the wood permeability. There are two simple methods to identify wood permeability: water soaking and bubble test methods. This paper assesses the young teak permeability by water soaking and bubble test methods. The assessment was conducted into five cm thick young-teak discs by soaking in the red-dye water and blowing air into the discs which had been coated with soap. Results show that the heartwood is less permeable than sapwood. Red-dye penetrates almost 100% of the sapwood area, and the red-dye did not penetrate in the heartwood. Red-dye only penetrates in the cracked heartwood through the void volume in the cracking heartwood. There is a transition zone between sapwood and heartwood, and it is refractory. Bubble test with air pressure from compressor could open the air-pathway in the heartwood and sapwood of young-teak discs taken from Bogor. The bubble test result of young-teak discs from Madiun showed air-pathway only in the sapwood, but heartwood. The air pressure is not capable of moving the vapour through the wood cell. It indicates that the heartwood of young-teak from Madiun is less permeable and less possibility for pressure treatment

Acoustic segregation of Pinus radiata logs according to stiffness

Wood stiffness varies enormously both within and between trees, so it is inevitable that low-grade solid wood products are produced from some trees. Accordingly, it would be highly desirable to segregate logs to ensure that only those logs with predominantly high stiffness wood are processed into structural lumber products. This study examined whether sound flight velocity (m s$^{-1}$) could be used as a direct measure of wood stiffness to allow such segregation. Trees of radiata pine were measured before and after harvest with a non-destructive acoustic device (stress wave timer) to see if there was a relationship between sound wave velocity in either standing trees or logs and machine stress-grades of boards derived from those trees and logs. The speed of sound along logs was sufficiently closely correlated with wood stiffness to allow logs to be sorted into classes. A highly significant and positive relationship was found for acoustic measurements made in logs and a weaker, but still significant, relationship existed for acoustic measurements made in standing trees. Such segregation of logs according to wave velocity measured in the field may save a large sawmill between A$1-4m each year. Acoustic methods may also be used as an indirect tool for selection provided the heritability of the measurements is high enough and there is significant genetic correlation with genetic values for wood stiffness. From another experiment we have estimated the heritability of several acoustic measures and hope to be able to estimate genetic relationships with wood quality soon.Classement des grumes de pin radiata selon le module d'élasticité par méthode acoustique. Les variations de module d'élasticité du bois, aussi bien inter- qu'intra- arbre peuvent être considérables. Il est alors inévitable de trouver des pièces de qualité mécanique médiocre en scierie. Il serait donc tout à fait souhaitable de pouvoir classer les grumes de telle sorte que seules celles qui pourront donner des sciages de qualité soient orientées pour la production de bois d'œuvre. Cette étude analyse la possibilité d'utiliser la vitesse de propagation du son dans le bois comme estimateur du module d'élasticité permettant un tel classement. Plusieurs pins radiata ont été mesurés avant et après abattage par une méthode non destructive afin d'analyser la relation entre la vitesse du son mesurée dans l'arbre sur pied ou la grume d'une part, et le classement mécanique sur machine des planches issues de ces grumes d'autre part. La corrélation positive et très significative mesurée sur grume est suffisamment élevée pour permettre le classement de ces grumes. Cette corrélation est plus faible, mais reste significative pour les mesures effectuées sur pied. Un classement des grumes effectué de cette façon sur chantier permettrait à une scierie de grande taille d'économiser de 1 à 4 millions de dollars australiens chaque année. Les méthodes acoustiques pourraient aussi être utilisées comme outil indirect pour la sélection génétique d'arbres de haute qualité mécanique, pourvu que l'héritabilité soit suffisante. Dans une autre série d'expérimentations l'héritabilité de plusieurs mesures acoustiques a été estimée et la liaison génétique/qualité du bois sera examinée

Wood Permeability Assessment of Young Teak (Tectona Grandis L.f.)

Wood properties of young teak (Tectona grandis L.f.) is inferior, and then preservative treatment is one possible solution to enhance its service life. The uptake and movement of preservatives through wood cell structure is directly connected to the wood permeability. There are two simple methods to identify wood permeability: water soaking and bubble test methods. This paper assesses the young teak permeability by water soaking and bubble test methods. The assessment was conducted into five cm thick young-teak discs by soaking in the red-dye water and blowing air into the discs which had been coated with soap. Results show that the heartwood is less permeable than sapwood. Red-dye penetrates almost 100% of the sapwood area, and the red-dye did not penetrate in the heartwood. Red-dye only penetrates in the cracked heartwood through the void volume in the cracking heartwood. There is a transition zone between sapwood and heartwood, and it is refractory. Bubble test with air pressure from compressor could open the air-pathway in the heartwood and sapwood of young-teak discs taken from Bogor. The bubble test result of young-teak discs from Madiun showed air-pathway only in the sapwood, but heartwood. The air pressure is not capable of moving the vapour through the wood cell. It indicates that the heartwood of young-teak from Madiun is less permeable and less possibility for pressure treatment

Variation of Heartwood Proportion and Wood Colour From Fast Grown 5-Year-Old Teak

The heartwood percentage and wood colour of Fast plantation grown teak destined for harvest at 5 years of age were characterized using automatic image processing 'ImageJ' routines and CieLab's colour system with the following coefficients: L for lightness, a* for redness and b* for yellowness. Analyses were conducted on material from different dry and wet sites. Comparison with 6-year old plantation from a dry site was conducted to study differences arising in older trees. Analyses of variation of those properties between and within different tree diameter classes were also conducted. The results showed that brightness, redness and yellowness values of 5-year old teak trees were 60.7, 10.7 and 23.1, respectively. Tree clone had a more dominant effect on wood colour and heartwood proportion than site, thus if specific colour preferences are needed of plantation trees, clone selection is important. The drier site produced larger proportions of heartwood in trees, as well as a more attractive figure. The trees produced heartwood proportions of 20% and 14% from the dry and wet sites respectively. On average, these 5 year old teak trees already produced 18% heartwood. Faster tree growth (larger diameter) appeared to have produced significantly larger heartwood proportions. Radially, the palest colour (the highest L but the lowest a*b* parameters) occurred in an area between heartwood and sapwood indicating the presence of a transition zone in all the tree samples

Global Wood Density Database

Please direct all correspondence to G. Lopez-Gonzale

The global spectrum of plant form and function: enhanced species-level trait dataset.

Here we provide the 'Global Spectrum of Plant Form and Function Dataset', containing species mean values for six vascular plant traits. Together, these traits -plant height, stem specific density, leaf area, leaf mass per area, leaf nitrogen content per dry mass, and diaspore (seed or spore) mass - define the primary axes of variation in plant form and function. The dataset is based on ca. 1 million trait records received via the TRY database (representing ca. 2,500 original publications) and additional unpublished data. It provides 92,159 species mean values for the six traits, covering 46,047 species. The data are complemented by higher-level taxonomic classification and six categorical traits (woodiness, growth form, succulence, adaptation to terrestrial or aquatic habitats, nutrition type and leaf type). Data quality management is based on a probabilistic approach combined with comprehensive validation against expert knowledge and external information. Intense data acquisition and thorough quality control produced the largest and, to our knowledge, most accurate compilation of empirically observed vascular plant species mean traits to date

The global spectrum of plant form and function: enhanced species-level trait dataset.

Here we provide the 'Global Spectrum of Plant Form and Function Dataset', containing species mean values for six vascular plant traits. Together, these traits -plant height, stem specific density, leaf area, leaf mass per area, leaf nitrogen content per dry mass, and diaspore (seed or spore) mass - define the primary axes of variation in plant form and function. The dataset is based on ca. 1 million trait records received via the TRY database (representing ca. 2,500 original publications) and additional unpublished data. It provides 92,159 species mean values for the six traits, covering 46,047 species. The data are complemented by higher-level taxonomic classification and six categorical traits (woodiness, growth form, succulence, adaptation to terrestrial or aquatic habitats, nutrition type and leaf type). Data quality management is based on a probabilistic approach combined with comprehensive validation against expert knowledge and external information. Intense data acquisition and thorough quality control produced the largest and, to our knowledge, most accurate compilation of empirically observed vascular plant species mean traits to date