Wood and Fiber Science (E-Journal)
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Field evaluation of physical barriers against subterranean termites and ambrosia beetles in a CLT wall envelope system
Full text linkThe effectiveness of physical barriers against subterranean termites was evaluated in a 34-week field test in coastal Mississippi by installing Obex11, a commercial polyethylene flashing, and Termimesh, a stainless-steel mesh in 3-ply 280mm(width) x 450mm(length) cross laminated timber (CLT) walls. Damage showed that both barriers performed significantly better than the no barrier control with respect to termite damage as evaluated by visual rating and mud tube length. Obex11, however, like the no barrier control, was more vulnerable to attack by Ambrosiodmus minor (Stebbing), an invasive ambrosia beetle, with both treatments exhibiting significantly longer bore trails than those found in Termimesh. 
USE OF A PORTABLE NEAR INFRARED SPECTROMETER FOR WOOD IDENTIFICATION OF FOUR DALBERGIA SPECIES FROM MADAGASCAR
Full text linkThis study focused on the use of Near InfraRed (NIR) Spectroscopy to address the lack of tools and skills for wood identification of Dalbergia species from Madagascar. Two sample sets of 41 wood blocks and 41 wood cores belonging to four Dalbergia species (D. abrahamii, D. chlorocarpa, D.greveana, and D. pervillei) were collected in the northern and western regions of Madagascar. Sapwood and heartwood NIR spectra were measured onwood at 12% moisture content by using a portable VIAVI MicroNIR 1700 spectrometer. Four discrimination models corresponding to sapwood and heartwood of the two sample forms were developed using Partial Least Square Discriminant Analysis (PLSDA).
Good accuracy of 83.3% and 81.8% were obtained from the heartwood-based PLSDA models respectively for wood blocks and wood cores samples. All D. chlorocarpa samples were well-classified by the two models. Results highlighted the potential of portable NIR Spectroscopy as a helpful tool tosupport sustain- able management and trade of Madagascar’s Dalbergia species. Further studies are, however, needed for its operational use in identification routine
COMPARING GC×GC-TOFMS-BASED METABOLOMIC PROFILING AND WOOD ANATOMY FOR FORENSIC IDENTIFICATION OF FIVE MELIACEAE (MAHOGANY) SPECIES
Full text linkIllegal logging and associated trade have increased worldwide. Such environmental crimes represent a major threat to forest ecosystems and society, causing distortions in market prices, economic instability, ecological deterioration, and poverty. To prevent illegal imports of forest products, there is a need to develop wood identification methods for identifying tree species regulated by the Convention on International Trade in Species of Wild Fauna andFlora in Trade (CITES) and other look-alike species. In this exploratory study, we applied metabolomic profiling of five species (Swietenia mahagoni, Swietenia macrophylla, Cedrela odorata, Khaya ivorensis, and Toona ciliata) using two-dimensional gas chromatog- raphy combined with time-of-flight mass spectrometry (GC3GC-TOFMS). We also performed qualitative, quantitative (based on the measurement of vessel area, tangential vessel lumina diameter,vessel element length, ray height, and ray width), and machine-vision aided (XyloTron) wood anatomy on a subsample of wood specimens to explore thepotential and limits of each approach. Fifty dried xylaria wood specimens were ground, extracted with methanol, and subsequently analyzed by GC3GC-TOFMS. In this study, the four genera could easily be identified using qualitative wood anatomy and chemical profiling. At the spe- cies level, Swietenia macrophylla and Swietenia mahagoni specimens were found to share many major metabolites and could only be differentiated after feature selection guided by cluster resolution (FS-CR) and visualization using Principal Component Analysis (PCA). Expectedly, specimens from the two Swiete- nia spp. could not be distinguished based on qualitative wood anatomy. However, significant differences in quantitative anatomical features were obtained for these two species. Excluding T. ciliata that was not included in the reference database of end grain images at the time of testing (2021), the XyloTron could successfully identify the majority of the specimens to the right genus and 50% of the specimens to the right species. The machine-vision tool was particularly successful at identifying Cedrela odorata samples, where all samples were correctly identified. Despite the limited number of specimens available for thisstudy, our preliminary results indicate that GC3GC-TOFMS-based metabolomic profiles could be used as comple- mentary method to differentiate CITES-regulated wood specimens at the genus and species levels.
Image analysis to assess wood variability in longleaf pine cross-sectional disks
Full text linkImage analysis is an important method for rapidly measuring wood property variation, but it is infrequently applied to disks collected from forestry studies. The objective of this study was to compare image estimated wood and bark volumes and diameters to reference measurements, and to extract more information from the images including the shape (out of round index, eccentric pith) and the amount and location of severe compression wood. A total of 1,120 disks were cut from multiple height levels of 48 defect-free and 56 defect-containing longleaf pine (Pinus palustris) trees from 16 stands across Georgia (U.S.). Disks were machined on one transverse surface using a computer numeric controlled router to prepare a clean surface for imaging. Three images; one under white light, second under blue light, and third under blue light with a green longpass filter, were taken for each disk. Volumes and diameters estimated from images were in close agreement with reference methods. Linear models fitted as measured versus image volumes for wood and bark had coefficient of determination (R2) values of >0.99 and 0.96. Linear models fitted as measured versus image diameters had R2 values of >0.99. Out of round index and pith eccentricity values calculated from images showed a moderate positive correlation (R=0.43). Algorithms developed were able to correctly identify severe compression wood, but not mild to moderate compression wood. Severe compression wood was moderately correlated to out of round index (R=0.54) and pith eccentricity (R=0.48). More than 98% of the disks having severe compression wood came from defect-containing trees
FLEXURAL AND TENSILE PROPERTIES OF 2 X 6 AND 2 X 10 SOUTHERN PINE LUMBER : Southenr pine lumber properties
No full textBending modulus of elasticity (MOE) and tensile properties parallel to the grain were studied on 702 pieces of 2 X 6 and 285 pieces of 2 X 10 No. 2 visually graded southern pine lumber. The overall rings per inch (RPI) in 2 X 6 pieces was 4.82, whereas 2 X 10 had an RPI average of 3.82. For latewood percentage (LW), 2 X 6 pieces found 45.88% of LW and 45.02% for 2 X 10 pieces. Bending MOE (Eb) mean for 2 X 6 was 10,615 MPa, whereas for 2 X 10 lumber, the mean was 13,665 MPa. The tension MOE (Et) mean for 2 X 6 lumber was 11,339 MPa, whereas for 2 X 10 the mean was 9735 MPa. The ultimate tensile stress (UTS) mean for 2 X 6 lumber was 28.42 MPa and the overall mean UTS for 2 X 10 lumber was 24.51 MPa. Linear regression models were useful to explain the relationship between Eb and Et. Strong coefficients of determination (r250.70 and r250.74) were found for both lumber sizes between these two properties. Moderate relationships (r250.43 up to r250.51) between Eb and UTS were also found for both lumber sizes. However, weaker relationships were found between Et and UTS (r250.32 up to r250.40). Three distributions were fit to the Eb, Et, and UTS data and evaluated for goodness of fit. The results suggest that Eb of 2 X 6 lumber might be adequately modeled by a normal distribution, and tensile properties of 2 X 10 lumber might be adequately modeled by a lognormal distribution
COMPARISON OF THE EFFECT OF TMP PITCH CONTROL AGENTS WITH DIFFERENT MECHANISMS
Full text linkThe pitch contained in thermomechanical pulp negatively affects paper quality, pulp, and the papermaking process. Serious pitch and stickies problems may occur in paper recycling processes. In this study, the effects of chemicals used to control the pitch in the TMP(Themomechanical Pulp) rocess were compared. The method used to analyze the pitch-control effect was to perform image analysis after using a reagent that selectively stains only the hydrophobic pitch. Three different mechanisms, namely fixation, detackification, and dispersion, were applied to solve the pitch problem from TMP. All the control agents were effective in pitch control, and, in particular, the agents related to fixation and dispersion were found to be more effective in reducing the number and area of tacky particles per unit area in sheets and white water. However, for the detackifiers and the dispersants, but not for the fixatives, it was difficult to clearly distinguish the difference of the pitch control effects according to the change in the amount of these agents through image analysis after staining
SUMMARY OF AWARDS 2021
No full textSummary of Awards presented at the 2021 International Meeting, held in Flagstaff, AZ, August 1 - 6, 2021
REVIEWED COMMENTARY: FACTORY-GROWN WOOD, THE FUTURE OF FORESTRY?
Full text linkRecent developments in factory-grown foods suggest that factory-grown wood (FGW) may be on the horizon. In fact, recent work at Massachusetts Institute of Technology introduces tunable plant-based materials, an early indicator of what may evolve into a new source of raw material for forest sector companies, and others. Industry and academia would be wise to monitor developments in this field as they may present significant opportunities and/or adjustments for both. We explore the state-of-the-art in this budding area of science and contemplate implications of successfully growing wood or other lignocellulosic materials in factories. Given a changing climate and focus on carbon emissions, the pressure to drastically reduce CO2 production will continue climb. Could reduction of their footprint via FGW be an important part of this equation for forest sector companies, going beyond the need to “make every tree count”? In other words, might FGW present an environmental and climate protection breakthrough? Or might it simply trade forest-based environmental impacts for others? What other consequences does FGW promise for companies? And, what might it mean for wood science programs, critical suppliers of research & development and skilled employees for the industry? We explore each of these questions and contemplate potential actions and outcomes.
EVALUATION OF XYLEM MATURTATION PROCESS AND EFFECTS OF RADIAL GROWTH RATE ON CELL MORPHOLOGIES IN WOOD OF BALSA (OCHROMA PRYAMIDALE) TREES
Full text linkThe radial variations of cell morphologies (cell lengths, vessel diameter, vessel frequency and cell wall thickness of wood fibers) were investigated for 7-year-old Ochroma pyramidale trees planted in East Java, Indonesia by developing the linear or nonlinear mixed-effects models. In addition, xylem maturation process based on the cell morphologies and effects of radial growth rate on cell morphologies were discussed. The mean values of cell morphology were as follow: vessel element length 0.59 mm, fiber length 2.16 mm, vessel diameter 221 µm, and fiber wall thickness 1.03 µm. Radial variations of cell length and vessel diameter were well explained by Michaelis-Menten equation: values increased from pith to certain position and then it became almost stable. Vessel frequency, wood fiber diameter, and wood fiber wall thickness was expressed by the formula of logarithmic formula, quadratic formula, and linear formula, respectively. Variance component ration of category was 66.8%, 46.1%, 31.4%, 1.5%, and 33.7% for vessel element length, wood fiber length, vessel diameter, vessel frequency, and wood fiber wall thickness, respectively, suggesting that many cell morphologies influenced by the radial growth rate. Smaller values of mean absolute error obtained in the models in relation to distance from pith were found in all cell morphologies, except for vessel frequency and wood fiber diameter. Thus, xylem maturation of this species depended on diameter growth rather than cambial age. Boundary of core wood and outer wood was 5 to 10 cm from pith in which increasing ratio of cell length reached less than 0.3%. Core wood was characterized as lower wood density and mechanical properties with shorter cell lengths and thinner wood fiber walls, whereas outer wood was characterized as higher wood density and mechanical properties with longer cell length and thicker wood fiber walls