This book was written to help the forest industry assess wood quality by using non-destructive samples taken from specific points within a tree. It is the first compilation of research data on sampling of eucalypts, describing new methods and tools for rapid and cost-effective analysis. The book provides information needed to design a sampling program, obtain and process wood samples, and shows how to relate the data to an average tree value.

-Traditional methods of assessing wood properties are both destructive and expensive, limiting the numbers of samples that can be processed. Over the past decade, non-destructive sampling techniques and new assessment methods have been developed leading to a large increase in the numbers of trees and traits that can be evaluated. This technology has enabled the assessment of progeny trials to determine the patterns of variation, degree of genetic control and economic importance of many wood traits, leading to the inclusion of wood properties in many eucalypt-breeding programs. Issues addressed in this paper include the potential markets and products for plantation eucalypts leading to a definition of which wood properties should be assessed for a range of products. Current recommendations for non-destructive sampling for basic density, fibre length and predicted pulp yield in Eucalyptus globulus and E. nitens are provided. Other non-destructive assessment techniques are illustrated including cellulose content, acoustic testing methods for wood stiffness and SilviScan X-ray densitometry and diffraction analysis for density and microfibril angle. The degree of genetic control for wood properties is compared to tree growth traits and a series of issues and challenges for the future presented.eucalypt / breeding / wood quality / genetic parameters / non-destructive sampling Résumé -Génétique des propriétés du bois d'Eucalyptus. Les méthodes traditionnelles pour déterminer les propriétés du bois sont à la fois destructives et chères, limitant le nombre d'échantillons pouvant être étudiés. Au cours des décennies passées, les techniques d'échantillonnage non destructives et les méthodes nouvelles d'évaluation ont été développées. Elles conduisent à une forte augmentation dans le nombre d'arbres et de caractères pouvant être évalués. Cette technologie a permis l'évaluation d'expériences progéniques afin de déterminer les formes de variation, le degré de contrôle génétique et l'importance économique de nombreuses caractéristiques du bois. Cela a conduit à l'incorporation de l'étude des propriétés du bois dans de nombreux programmes d'amélioration de l'eucalyptus. Les messages adressés dans ce papier incluent les marchés et produits potentiels pour les plantations d'eucalyptus conduisant à une définition pour laquelle les propriétés du bois devront être prises en compte pour une série de produits. Les recommandations actuelles sont données pour le cas d'un échantillonnage non destructif pour la mesure de la densité basique du bois, de la longueur de fibre et la production prévisible de pâte pour Eucalyptus globulus et E. nitens. D'autres évaluations techniques non destructives sont illustrées. Elles incluent la teneur en cellulose, des méthodes de test acoustique pour la dureté du bois et des analyses densitométriques et de diffraction par l'analyseur rayons X, SilviScan, pour la densité et l'angle des microfibres. Le niveau de contrôle génétique pour les propriétés du bois est comparé aux caractéristiques de la ...

This study considered the degree of genetic variation for diameter (DBH), basic density (BD), predicted pulp yield (PPY), fibre length (FL), microfibril angle (MFA) and cellulose content (CC) amongst eight subraces of Eucalyptus globulus growing in a field trial in NW Tasmania. There were significant subrace effects for BD, FL and CC. This variation affected the relative profitability of the subraces for pulp production. On average, the most profitable subraces (on NPV/ha over the base population mean) were Strzelecki Ranges ($862.04), Western Otways ($657.80) and Strzelecki Foothills ($576.81). The genetic control (heritability) of variation in DBH, FL and MFA was moderate (0.15 < h2< 0.27), while control for BD, PPY and CC was high (h2> 0.40). Genetic correlations between growth and wood properties were not statistically significant, except for DBHMFA (-0.86). Most genetic correlations amongst wood properties were outside the parametric space (< -1 or >1), but there were significant correlations between BDMFA (-0.70) and PPY-CC (0.82). The empirical response to selection on an index based on a pulp wood objective (which included volume and basic density) resulted in a gain of 4.3% for DBH, 7.9% for BD and marginal changes for all other traits, with a net impact in profit of $1,270/ha. However, future profit calculations will need to consider the effect of FL, MFA and CC on the economics of wood processing to fully evaluate the economic impact of breeding.

Determining kraft pulp yield in the traditional way is slow and expensive, limiting the numbers of samples that may be processed. An alternative is to use a secondary standard, such as cellulose content of the wood, which is strongly correlated with kraft pulp yield. The feasibility and efficiency of predicting cellulose content using near infrared reflectance (NIR) analysis was examined for Eucalyptus globulus Labill. Calibrations for NIR prediction of cellulose content indicated that NIR analysis could be used as a reliable predictor. Standard errors of calibration were 1% or lower, and there was excellent agreement between laboratory and predicted cellulose values. Cellulose content was under moderate genetic control (h2 ranging from 0.32 to 0.57), and genetic correlations with tree diameter and basic density were variable (ranging from –0.11 to –0.51 and –0.33 to 0.67, respectively). The advantages, disadvantages, and potential applications of NIR analysis for predicting cellulose content are examined.