Carolyn A Raymond

Predicting Extractives, Lignin, and Cellulose Contents Using Near Infrared Spectroscopy on Solid Wood in Eucalyptus globulus

Abstract Near infrared reflectance (NIR) spectroscopy can be used to reliably predict both the physical and chemical wood properties of Eucalyptus. However, studies have been based on ground wood, which is costly and time‐consuming to obtain. Predicting wood traits from NIR spectral data taken from solid wood would greatly increase the speed and cost‐effectiveness of this procedure. Existing ground wood calibrations were evaluated for the prediction of wood chemistry from NIR spectral data taken from solid wood. Extractives, acid‐soluble lignin, and Klason lignin contents were poorly predicted. Total lignin and cellulose contents showed moderate relationships between laboratory values and the NIR predicted values. NIR calibrations were further developed specifically for predicting wood chemistry from solid wood. All calibrations had high R2 values from 0.72 to 0.88, and standard errors of calibration were less than 1.37%. Calibration validation produced high correlation coefficients between predicted and laboratory values for extractives, Klason lignin, total lignin, and cellulose contents with R2 values ranging from 0.67 to 0.87. Acid‐soluble lignin content was poorly predicted. This study showed that NIR analysis on solid wood of E. globulus could be reliably used to predict extractives, lignin, and cellulose contents. It also determined that existing ground wood calibrations, although they could give crude estimates of the wood chemistry values, would need to be re‐developed for accurate predictions from solid wood.

Nondestructive sampling of Eucalyptus globulus and E. nitens for wood properties I: basic density

Abstract A non-destructive sampling strategy for basic density, based on removing 12 mm bark-to-bark cores, was developed in E. globulus and E. nitens. Fifty trees of each species, aged 5 to 9 years, were sampled across a range of sites. Core samples were removed on both a north-south and an east-west axis from 6 fixed heights in the base of the tree (0.5 m, 0.7 m, …, 1.5 m). Whole-tree values were calculated from disc samples removed at eight percentage heights (0, 10, 20, …, 70%) and correlations between the cores and whole-tree values were used to determine the optimal sampling height. Core samples were found to be reliable predictors of whole-tree density, explaining between 84% and 89% of the variation between trees. Core sampling of E. globulus and E. nitens to estimate basic density of whole-trees and stands is feasible; cores from trees at all E. globulus sites gave high correlations with whole-tree values. For E. nitens, site differences were apparent, and it is recommended that a small destructive sampling program should be undertaken prior to commencing a major sampling program. Recommended optimal sampling heights are 1.1 m for E. globulus and 0.7 m for E. nitens. Core orientation was not important and density was not related to tree size. Six whole-tree samples or eight core samples are required for estimating the mean density of a stand at a specific site to an accuracy of ±20 kg m−3 with a 95% confidence interval.

Segregation of Eucalyptus dunnii logs using acoustics

Abstract Wood properties at harvest-age vary enormously both within and among Eucalyptus trees, leading to a wide range in sawlog quality. One key property determining value of sawn boards is wood stiffness, with boards being allocated to different strength classes and priced accordingly. To maximise returns from sawing, it is highly desirable to be able to sort logs, either in the field or log yard, to ensure that only the higher quality logs are sawn. A non-destructive testing method for assessing wood stiffness, sound flight velocity, was evaluated as a direct measure of wood stiffness using two age classes (9- and 25-year-old) of Eucalyptus dunnii. Trees were measured before and after harvest with a non-destructive acoustic device (FAKOPP stress wave timer), sawn, and all boards tested acoustically prior to and after drying and reconditioning. A subset of boards was then put through a stress-grading machine to determine stiffness, and later tested for wood hardness. Wood samples were also collected from the logs to determine basic density, and relationships between stiffness, hardness, wood density and sound flight time in trees and logs were determined. The speed of sound along logs was sufficiently closely correlated with wood stiffness to allow logs to be sorted into stiffness classes. A highly significant and positive relationship was found for acoustic measurements made on logs while a weaker, but still significant, relationship existed for acoustic measurements made on standing trees. For the sawn boards, sound flight velocity in both green and kiln dried boards was strongly correlated with both stiffness and wood hardness. Stiffness was significantly positively correlated with wood hardness at both ages in both logs and boards, indicating that segregation based on increasing stiffness would lead to improvements in hardness. This study identified the need for further work on the methodology and hardware required for the segregation of Eucalyptus logs to optimise value recovery.

Genetic variation of physical and chemical wood properties

Abstract 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 (

Predicting Extractives and Lignin Contents in Eucalyptus globulus Using Near Infrared Reflectance Analysis

862.04), Western Otways (

Where to shoot your pilodyn : Within tree variation in basic density in plantation Eucalyptus globulus and E. nitens in Tasmania

657.80) and Strzelecki Foothills (

Nondestructive sampling of Eucalyptus globulus and E. nitens for wood properties III: predicted pulp yield using near infrared reflectance analysis

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

Genetic variation in Eucalyptus nitens pulpwood and wood shrinkage traits

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.

Pectin Methylesterase Genes Influence Solid Wood Properties of Eucalyptus pilularis

Abstract Lignin and extractive content are important determinants of the pulping quality of wood. Determination of extractive and lignin content using traditional chemical methods is a costly and time‐consuming process. Near infrared reflectance (NIR) analysis offers a low cost alternative for prediction of wood quality. Calibrations were developed for the prediction of extractives content, acid‐soluble lignin, Klason lignin, and total lignin contents. Each calibration had standard errors of less than 0.6%. Laboratory measurements for a separate set of samples were highly correlated with predicted values (R 2 of 0.89 for extractives content, 0.83 for acid‐soluble lignin content, 0.97 for Klason lignin content, and 0.99 for total lignin content). It was concluded that NIR analysis is a reliable predictor of extractive and lignin content in Eucalyptus globulus.

Effects of moisture content and temperature on acoustic velocity and dynamic MOE of radiata pine sapwood boards

Longitudinal patterns of within tree variation for basic density were determined for plantation Eucalyptus globulus (ages 5 and 10 years) and E. nitens (ages 5, 10 and 15 years) growing in three geographic areas in Tasmania. Each tree was sampled by taking discs from a combination of percentage heights (0, 10, 20 ___ 70%) and fixed height samples (0.5 m, 0.7 m ___ 1.5 m). At each of the fixed heights, a single pilodyn reading was taken from each of 4 aspects. Weighted whole tree density was calculated from the percentage height samples and used for correlation and regression analysis with the fixed height samples. Both species showed an initial drop in density between the felling cut (zero height) and 0.5 m, followed by a linear increase in density between 10% and 70% of tree height. Slope of fitted regressions were parallel within species but differed significantly between the species (1.14 kg/m3 and 1.62 kg/m3 per 1% increase in height above 10% for E. globulus and E. nitens, respectively). Density at all fixed heights was highly correlated with whole tree values for E. globulus, but results were variable across sites for E. nitens. Both species were found to contain trees which produced aberrant pilodyn readings. For E. globulus, the optimal sampling height was 1.3 m above ground and the mean pilodyn reading was found to predict whole tree density with an accuracy of ±21 kg/m3. For E. nitens, optimal sampling height was 1.5 m above ground. However, pilodyn readings around the stem were not very repeatable and correlations with whole tree density were lower, resulting in the accuracy of prediction of whole tree density being ±26 kg/m3.