scholarly journals Radial variation in modulus of elasticity, microfibril angle and wood density of veneer logs from plantation-grown Eucalyptus nitens

2020 ◽  
Vol 77 (3) ◽  
Author(s):  
Mario Vega ◽  
Matthew Hamilton ◽  
Geoff Downes ◽  
Peter A. Harrison ◽  
Brad Potts
Keyword(s):  
Wood Density ◽  
Modulus Of Elasticity ◽  
Microfibril Angle ◽  
Radial Variation ◽  
Eucalyptus Nitens

Intra-specific competition and the radial development of wood density, microfibril angle and modulus of elasticity in plantation-grown Eucalyptus nitens

Trees ◽  
2012 ◽  
Vol 26 (6) ◽  
pp. 1771-1780 ◽  
Author(s):  
Jane Medhurst ◽  
Geoff Downes ◽  
Maria Ottenschlaeger ◽  
Chris Harwood ◽  
Rob Evans ◽  
...  
Keyword(s):  
Wood Density ◽  
Modulus Of Elasticity ◽  
Microfibril Angle ◽  
Eucalyptus Nitens

Temporal variation in δ13C, wood density and microfibril angle in variously irrigated Eucalyptus nitens

2009 ◽  
Vol 36 (1) ◽  
pp. 1 ◽  
Author(s):  
David M. Drew ◽  
E. Detlef Schulze ◽  
Geoffrey M. Downes
Keyword(s):  
Water Stress ◽  
Temporal Variation ◽  
Wood Density ◽  
Stable Carbon Isotope ◽  
Microfibril Angle ◽  
Wood Property ◽  
Wood Properties ◽  
Eucalyptus Nitens ◽  
Stable Carbon ◽  
Over Time

Wood can serve as a record of past climate, recording tree responses to changing conditions. It is also valuable in understanding tree responses to environment to optimise forest management. Stable carbon isotope ratios (δ13C), wood density and microfibril angle (MFA) are potentially useful wood property parameters for these purposes. The goal of this study was to understand how δ13C varied over time in response to cycles of soil drying and wetting and to variation in temperature in Eucalyptus nitens Deane & Maiden, in concert with wood density and MFA. δ13C increases did not necessarily occur when water stress was highest, but, rather, when it was relieved. Our hypothesis is that this was a result of the use of previously fixed carbohydrate reserves when growth and metabolic activity was resumed after a period of dormancy. MFA in particular showed concomitant temporal variation with δ13C. A peak in δ13C may not coincide temporally with an increase in water stress, but with a decrease, when higher growth rates enable the final incorporation of earlier stored photosynthate into mature wood. This has implications for using δ13C as a tool to understand past environmental conditions using radial measurements of wood properties. However, interpreting this data with other wood properties may be helpful for understanding past tree responses.

Influence of stocking on radial and longitudinal variation in modulus of elasticity, microfibril angle, and density in a 24-year-old Pinus radiata thinning trial

2011 ◽  
Vol 41 (7) ◽  
pp. 1422-1431 ◽  
Author(s):  
Michael S. Watt ◽  
Branislav Zoric ◽  
Mark O. Kimberley ◽  
Jonathan Harrington
Keyword(s):  
Wood Density ◽  
Pinus Radiata ◽  
Modulus Of Elasticity ◽  
Significant Interaction ◽  
Graphical Model ◽  
Microfibril Angle ◽  
Wood Properties ◽  
Tree Age ◽  
Longitudinal Variation ◽  
Maximum Difference

Detailed radial measurements of wood properties at four heights (0, 1.4, 5, and 20 m) were taken from 24-year-old Pinus radiata D. Don growing at four final crop stockings (200, 350, 500, and 1100 stems·ha–1). Using these measurements, the objectives of the study were to examine pith-to-bark trends at several heights to (i) determine how stocking influenced modulus of elasticity (MoE), wood density, and microfibril angle (MFA), (ii) quantify the relations among these properties and age at different stocking levels, and (iii) develop a graphical model for MoE across the stocking range. The influence of stocking on all wood properties was primarily expressed through a highly significant interaction between age and stocking. Wood properties in the highest stocking treatment diverged from those in the lowest stocking treatment at tree age 5 to reach a maximum difference of 92 kg·m–3 (488 vs. 580 kg·m–3) at tree age 18 for density, –5.7° (29.2° vs. 23.5°) at tree age 10 for MFA, and 5.1 GPa (12.1 vs. 17.2 GPa) at tree age 20 years for MoE. Graphical predictions from the model show greatest gains in MoE at high final crop stocking to occur over the lower part of the stem.

Radial Variation in Cellulose Content and Kraft Pulp Yield in Eucalyptus Nitens using Near-Infrared Spectral Analysis of Air-Dry Wood Surfaces

2010 ◽  
Vol 18 (2) ◽  
pp. 147-154 ◽  
Author(s):  
Geoffrey M. Downes ◽  
Roger Meder ◽  
Nicholas Ebdon ◽  
Helen Bond ◽  
Robert Evans ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Kraft Pulp ◽  
Near Infrared ◽  
Radial Variation ◽  
Pulp Yield ◽  
Cellulose Content ◽  
Eucalyptus Nitens ◽  
Infrared Spectral ◽  
Dry Wood ◽  
Wood Surfaces

Predicting the longitudinal modulus of elasticity of Sitka spruce from cellulose orientation and abundance

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
J. Paul McLean ◽  
Robert Evans ◽  
John R. Moore
Keyword(s):  
Bulk Density ◽  
Modulus Of Elasticity ◽  
Microfibril Angle ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Model Parameters ◽  
Bending Tests ◽  
Wood Stiffness ◽  
Using Data ◽  
Longitudinal Modulus

Abstract Sitka spruce (Picea sitchensis) is the most widely planted commercial tree species in the United Kingdom and Ireland. Because of the increasing use of this species for construction, the ability to predict wood stiffness is becoming more important. In this paper, a number of models are developed using data on cellulose abundance and orientation obtained from the SilviScan-3 system to predict the longitudinal modulus of elasticity (MOE) of small defect-free specimens. Longitudinal MOE was obtained from both bending tests and a sonic resonance technique. Overall, stronger relationships were found between the various measures of cellulose abundance and orientation and the dynamic MOE obtained from the sonic resonance measurements, rather than with the static MOE obtained from bending tests. There was only a moderate relationship between wood bulk density and dynamic MOE (R2=0.423), but this relationship was improved when density was divided by microfibril angle (R2=0.760). The best model for predicting both static and dynamic MOE involved the product of bulk density and the coefficient of variation in the azimuthal intensity profile (R2=0.725 and 0.862, respectively). The model parameters obtained for Sitka spruce differed from those obtained in earlier studies on Pinus radiata and Eucalyptus delegatensis, indicating that the model might require recalibration before it can be applied to different species.

scholarly journals Acoustic-Based Prediction of End-Product-Based Fibre Determinates within Standing Jack Pine Trees

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 605
Author(s):  
Peter F. Newton
Keyword(s):  
Wood Density ◽  
Pinus Banksiana ◽  
Goodness Of Fit ◽  
Prediction Models ◽  
Microfibril Angle ◽  
Model Performance ◽  
Predictive Ability ◽  
Analytical Framework ◽  
Jack Pine ◽  
Cross Sectional

The objective of this study was to specify, parameterize, and evaluate an acoustic-based inferential framework for estimating commercially-relevant wood attributes within standing jack pine (Pinus banksiana Lamb) trees. The analytical framework consisted of a suite of models for predicting the dynamic modulus of elasticity (me), microfibril angle (ma), oven-dried wood density (wd), tracheid wall thickness (wt), radial and tangential tracheid diameters (dr and dt, respectively), fibre coarseness (co), and specific surface area (sa), from dilatational stress wave velocity (vd). Data acquisition consisted of (1) in-forest collection of acoustic velocity measurements on 61 sample trees situated within 10 variable-sized plots that were established in four mature jack pine stands situated in boreal Canada followed by the removal of breast-height cross-sectional disk samples, and (2) given (1), in-laboratory extraction of radial-based transverse xylem samples from the 61 disks and subsequent attribute determination via Silviscan-3. Statistically, attribute-specific acoustic prediction models were specified, parameterized, and, subsequently, evaluated on their goodness-of-fit, lack-of-fit, and predictive ability. The results indicated that significant (p ≤ 0.05) and unbiased relationships could be established for all attributes but dt. The models explained 71%, 66%, 61%, 42%, 30%, 19%, and 13% of the variation in me, wt, sa, co, wd, ma, and dr, respectively. Simulated model performance when deploying an acoustic-based wood density estimate indicated that the expected magnitude of the error arising from predicting dt, co, sa, wt, me, and ma prediction would be in the order of ±8%, ±12%, ±12%, ±13%, ±20%, and ±39% of their true values, respectively. Assessment of the utility of predicting the prerequisite wd estimate using micro-drill resistance measures revealed that the amplitude-based wd estimate was inconsequentially more precise than that obtained from vd (≈ <2%). A discourse regarding the potential utility and limitations of the acoustic-based computational suite for forecasting jack pine end-product potential was also articulated.

scholarly journals The effect of planting spacing on Pinus patula stem straightness, microfibril angle and wood density

2018 ◽  
Vol 91 (3) ◽  
pp. 247-258 ◽  
Author(s):  
Justin Erasmus ◽  
Anton Kunneke ◽  
David M Drew ◽  
C Brand Wessels
Keyword(s):  
Wood Density ◽  
Microfibril Angle ◽  
Pinus Patula ◽  
Stem Straightness

scholarly journals Use of Time-of-Flight Ultrasound to Measure Wave Speed in Poplar Seedlings

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 682 ◽  
Author(s):  
Fenglu Liu ◽  
Pengfei Xu ◽  
Houjiang Zhang ◽  
Cheng Guan ◽  
Dan Feng ◽  
...  
Keyword(s):  
Ultrasonic Velocity ◽  
Wood Density ◽  
Microfibril Angle ◽  
Negative Relationship ◽  
Acoustic Resonance ◽  
Ultrasonic Speed ◽  
Root Collar Diameter ◽  
Collar Diameter ◽  
Root Collar ◽  
Poplar Seedlings

In this study, 145 poplar (Populus × euramericana cv.’74/76’) seedlings, a common plantation tree species in China, were selected and their ultrasonic velocities were measured at four timepoints during the first growth year. After that, 60 poplar seedlings were randomly selected and cut down to determine their acoustic velocity, using the acoustic resonance method. The effects of influencing factors such as wood green density, microfibril angle, growth days, and root-collar diameter on acoustic speed in seedlings and the relationship between ultrasonic speed and acoustic resonance speed were investigated and analyzed in this work. The number of specimens used for investigating growth days and root-collar diameter was 145 in both cases, while 60 and two specimens were used for investigating wood density and the microfibril angle, respectively. The results of this study showed that the ultrasonic speed of poplar seedlings significantly and linearly increased with growth days, within 209 growing days. The ultrasonic velocity of poplar seedlings has a high and positive correlation with growth days, and the correlation was 0.99. However, no significant relationship was found between the ultrasonic velocity and root-collar diameter of poplar seedlings. Furthermore, a low and negative relationship was found between wood density and ultrasonic speed (R2 = 0.26). However, ultrasonic velocity significantly decreased with increasing microfibril angle (MFA) in two seedlings, and thus MFA may have an impact on ultrasonic speed in poplar seedlings. In addition, ultrasonic velocity was found to have a strong correlation with acoustic resonance velocity (R2 = 0.81) and a good correlation, R2 = 0.75, was also found between the dynamic moduli of elasticity from ultrasonic and acoustic resonance tests. The results of this study indicate that the ultrasonic technique can possibly be used to measure the ultrasound speed of young seedlings, and thus early screen seedlings for their stiffness properties in the future.

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