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 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 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.

Direct Effects of Wood Characteristics on Pulp and Handsheet Properties of Eucalyptus globulus

Holzforschung ◽  
2002 ◽  
Vol 56 (3) ◽  
pp. 244-252 ◽  
Author(s):  
R. Wimmer ◽  
G.M. Downes ◽  
R. Evans ◽  
G. Rasmussen ◽  
J. French
Keyword(s):  
Wood Density ◽  
Eucalyptus Globulus ◽  
Strong Predictor ◽  
Fibre Length ◽  
Microfibril Angle ◽  
Wood Properties ◽  
Bending Stiffness ◽  
Pulp Yield ◽  
Paper Properties ◽  
Handsheet Properties

Summary Fibre length, microfibril angle and wood density were measured in eight-year-old Eucalyptus globulus clones planted on three different sites. Samples were chipped and pulped, and the pulps beaten prior to preparation of 60g/m2 handsheets. Eleven physical handsheet properties, together with pulp freeness, were measured using standard methods. Direct relationships between wood properties and pulp/paper properties were studied using path analysis. Fibre length had a strong, direct effect on tear index, bending stiffness, freeness, pulp yield and active alkali consumption. Wood density was a strong predictor of most handsheet properties: high density woods produced bulkier, more porous sheets with higher bending stiffness, while lower density woods produced smoother, denser sheets with higher tensile strength.The effect of microfibril angle was small and more evident in handsheets made from beaten pulp.

Relationships between Density, Shrinkage, Extractives Content and Microfibril Angle in Tension Wood from Three Provenances of 10-Year-Old Eucalyptus globulus Labill

Holzforschung ◽  
2001 ◽  
Vol 55 (2) ◽  
pp. 176-182 ◽  
Author(s):  
R. Washusen ◽  
P. Ades ◽  
R. Evans ◽  
J. Ilic ◽  
P. Vinden
Keyword(s):  
Wood Density ◽  
Eucalyptus Globulus ◽  
Tension Wood ◽  
Microfibril Angle ◽  
Positive Association ◽  
Normal Wood ◽  
X Ray Diffraction ◽  
X Ray ◽  
Saturation Method ◽  
Improvement Programs

Summary Density and microfibril angle (MFA) of tension wood and normal wood were assessed in the sapwood and heartwood, from three provenanaces of 10-year-old Eucalyptus globulus Labill. Density was measured using a modified saturation method that also enabled the calculation of the extractives lost during saturation. Microdensity and MFA were determined by SilviScan 2, a rapid X-ray densitometry and X-ray diffraction system developed at CSIRO. Significant differences were found in density and extractives between provenances and also density between the sapwood and adjacent heartwood from each provenance. This result may explain some of the drying differences between provenances found in an earlier study (Washusen and Ilic 2000). Sapwood samples with high percentages of tension wood fibres had high density and a significant positive correlation was found between microdensity and tension wood fibre percentage. MFA was found to be very low in normal wood in the sapwood, where most tension wood was found, so tension wood could not be identified by MFA. The positive association between tension wood and wood density suggests that caution should be taken when selecting trees for high wood density in tree improvement programs.

High spatial resolution and non-destructive evaluation of wood density and microfibril angle by NIR hyperspectral imaging

NIR news ◽  
2017 ◽  
Vol 28 (5) ◽  
pp. 7-12 ◽  
Author(s):  
Te Ma ◽  
Tetsuya Inagaki ◽  
Satoru Tsuchikawa
Keyword(s):  
Hyperspectral Imaging ◽  
Wood Density ◽  
Spatial Resolution ◽  
Cross Validation ◽  
High Spatial Resolution ◽  
Microfibril Angle ◽  
Coefficient Of Determination ◽  
X Ray ◽  
Effective Manner ◽  
Non Destructive

Wood density and microfibril angle are strongly correlated with wood stiffness, shrinkage, and anisotropy. Understanding the spatial distribution of these values is critical for solid timber applications. In this study, near infrared (NIR) hyperspectral imaging was used to evaluate wood density and microfibril angle in a non-destructive, yet effective manner. Briefly, five wood samples collected from both normal and compression parts of two different Cryptomeria japonica trees were analyzed. Partial least squares regression analysis was performed to determine the relationship between X-ray reference data and NIR spectra, and cross-validation (leave-one-out) was used for checking prediction performances. The validation coefficient of determination (r2) between predicted densities by the NIR technique and measured values by SilviScan (X-ray data) was 0.83 with a root mean squared error of cross-validation (RMSECV) of 105.18 kg/m3. Regarding microfibril angle, r2 and RMSECV were 0.77 and 5.36°, respectively. Finally, wood density and microfibril angle were successfully mapped at a high spatial resolution (156 µm) to facilitate the detection of annual growth ring features and evaluation of aspects of heterogeneous wood quality.

Anatomical properties of Hibiscus macrophyllus and its mature wood development

IAWA Journal ◽  
2021 ◽  
Vol 42 (4) ◽  
pp. 475-485
Author(s):  
Efrida Basri ◽  
Ratih Damayanti ◽  
Atmawi Darwis ◽  
Saefudin ◽  
Imam Wahyudi
Keyword(s):  
Wood Density ◽  
Fibre Length ◽  
Microfibril Angle ◽  
Mature Wood ◽  
Tree Age ◽  
Vessel Element ◽  
Plantation Forest ◽  
X Ray Diffraction ◽  
Wood Development ◽  
Anatomical Properties

Abstract The Hibiscus macrophyllus tree is widely planted in Indonesia especially on Java Island. It has several advantages to be developed commercially as a community or plantation forest compared to the famous introduced species Falcataria moluccana and Anthocephalus spp., including faster growth, higher wood density, and better stem morphology (straighter, more rounded, and lesser branches). However, information about the basic properties of this wood grown in plantations is limited. This study aimed to investigate the anatomical properties of H. macrophyllus and their variation at three ages (8, 12 and 16 years old), as well as to predict the mature wood development by using radial variation in fiber length, microfibril angle (MFA), and wood density from pith toward the bark as the indicators. The wood samples were obtained from a community forest area at Ciamis Regency, West Java Province. Furthermore, anatomical characteristics were examined through wood slides following the IAWA List, while fibre and vessel element dimensions were measured through macerated specimens prepared by modified Franklin’s method. The MFA was determined by X-Ray Diffraction, while wood density was measured in line with British Standard 373-57. The results showed that the anatomical structures were not influenced by tree age, except for wood porosity, and fibre and vessel element dimensions. The 16-year-old tree tended to be semi-ring-porous, the younger trees were diffuse-porous, while the fiber and vessel element length, as well as the diameter, were decreased. Meanwhile, the wall thickness was increased. The fibre length, MFA, and wood density were useful indicators for wood maturity that seemed to be developed at about 11 years of age.

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

scholarly journals ANATOMICAL CHARACTERISTICS AND MECHANICAL PROPERTIES OF LARIX SIBIRICA GROWN IN SOUTH-CENTRAL SIBERIA

IAWA Journal ◽  
2003 ◽  
Vol 24 (4) ◽  
pp. 355-370 ◽  
Author(s):  
Akio Koizumi ◽  
Katsuhiko Takata ◽  
Kana Yamashita ◽  
Ryogo Nakada
Keyword(s):  
Mechanical Properties ◽  
Wood Density ◽  
Microfibril Angle ◽  
Average Density ◽  
Larix Sibirica ◽  
Larix Kaempferi ◽  
Mountain Range ◽  
Spiral Grain ◽  
South Central ◽  
Tracheid Length

Tracheid length, microfibril angle, spiral grain, wood density, MOE, MOR, compressive strength, modulus of rigidity and their inter-relationships were investigated for fifty Siberian larch trees (Larix sibirica) collected from five natural stands. No inter-stand variation in tracheid length, microfibril angle and spiral grain was observed. No effect of tracheid length and microfibril angle on the mechanical properties was observed. Inter-stand variation in wood density was significant, especially for mature wood. The wood from the Baikal site in the eastern range of the natural distribution had a very high density. The wood from the Altai site in the mountain range had a low density, especially within the latewood. Minimum density within a ring seemed to be the major source of variation for average density within the heartwood, whereas the effect of maximum density on average density was greater within the sapwood. Wood density, which was much higher for a given ring width than in plantation-grown Japanese larch (Larix kaempferi), had a major effect on the mechanical properties.

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.

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