• Journal of the Korea Furniture Society
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• v.17 no.3
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• pp.29-36
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• 2006

Juvenile and matured wood of Populus tomentiglandulosa species of Salicaceae native grown in Korea was observed by FE-SEM and optical microscope. Species is characterized by mostly diffuse-porous, simple perforation plates, polygonal alternate non-vestured intervessel pit, medium length of vessel elements and fibres, non-septate very thin walled libriform fibres and exclusively uniseriate procumbent rays. Axial parenchyma was absent or extremely rare. Vessel and fibre length were longer in both matured and juvenile latewood than those of earlywood. Ray cell lumen diameter, ray length, number and diameter of endwall pit in ray cell, endwall pit, number and diameter of pit in lateral wall of one ray parenchyma cell, vessel ray pit number and diameter vary from juvenile early and latewood to matured wood.

• Journal of agriculture & life science
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• v.45 no.1
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• pp.9-14
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• 2011

Larix kaempferi is a tree with a major economic impact and is processed in large quantity every year in Korea. This study was carried out to collect basic data for the reasonable use of Larix kaempferi and to investigate the relation between anatomical properties and modulus of rupture (MOR) for heartwood and sapwood. As the length of earlywood tracheid and the radial wall thickness of earlywood tracheid and latewood tracheid increased, the modulus of rupture (MOR) increased, but decreased with increasing microfibril angle. Statistical analysis by the stepwise regression technique shows that the main factors affecting the modulus of rupture (MOR) of heartwood are the microfibril angle and the radial wall thickness of latewood tracheid, while those affecting MOR of sapwood are the length of earlywood tracheid and the microfibril angle.

• Journal of the Korean Wood Science and Technology
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• v.36 no.3
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• pp.55-60
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• 2008

This study was carried out to investigate the effect of charcoal meal application on the quality of the wood. As the results, it was observed that annual ring width of seedlings was wider in the plots treated with charcoal meal than the control plots. Depending on the kind of charcoal, annual ring width was widest in the plot treated with Larix kaempferi charcoal, and then was observed in order of Pinus koraiensis > particle board > Quercus acutissima. Latewood percentage and specific gravity were lower in the plots treated with charcoal than the control plots and lowest in Larix kaempferi charcoal plot among the plots treated with charcoal. Tracheid length was longer in the plot treated with powder charcoal than the control plot but tracheid width was not significantly different from the control plot. The cell wall thickness of earlywood was not significantly different between the plot treated with charcoal and the control plot but that of latewood was thicker in the plots treated with charcoal than the control. Microfibril angle was smaller in the plot treated with granulated charcoal than the control plot. However, there was no significant difference between the plot treated with powder charcoal and granulated charcoal.

• Journal of the Korean Wood Science and Technology
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• v.36 no.3
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• pp.17-23
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• 2008

The purpose of this study is to estimate the shrinkage of wood by LV-SEM (Low-Vacuum Scanning Electron Microscope) which can observe wetted wood sample. The shrinkage of small sample specimen by the dehumidification in the specimen chamber was investigated and compared with that of normal wood specimen. The observation of cross sectional surface of wood from wetted condition to dried condition can be achieved in about twenty minutes by means of the dehumidification in the specimen chamber of LV-SEM. The volumetric shrinkage of earlywood was almost the same as that of latewood. The shrinkage of SEM observation specimen was similar to that of normal wood specimen. From the correlation of the shrinkages between SEM observation specimen and normal wood specimen, it is surmised that the shrinkage of wood is more strictly dominated by shrinkage of latewood than that of earlywood.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.23-30
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• 2007

Round piles of Korean larch were excavated from the foundation of ex-Chosunchongdokbu (ex-Chosun Governer-General Building), which was constructed in 1916 and dismantled later in 1996. By the record (Huh, 1996), the Korean larch logs were logged from the Yalu river area near Mt. Baekdu in North Korea. At present, however, Korean larch is not so popular in South Korea. The latewood ratio profiles and strength properties (longitudinal compression, shear, longitudinal tensile, and bending) were obtained. The ratio of latewood from pith to bark increased up to 25 years, and then it showed constant tendency at 40% with some variances. From the microscopic observation, however, the latewood ratio decreased from the heartwood to the sapwood. Compression strength was greater and bending strength was a little lower than the previous reports (references 13~15), which might be attributed to the strength reduction of old structural members by aging or damage in the compression specimens than the bending ones. The flat-grained specimens for the shear and tension test showed higher coefficient of variation (COV) than the edge-grained ones. For the better comparison of results, in case of shear and tensile strength tests, the strength values of the edge-grained specimens were thought to be adopted rather than those of flat-grained ones.

• Journal of the Korean Wood Science and Technology
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• v.52 no.3
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• pp.289-299
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• 2024

The current study aimed to investigate the impact of CO₂ enrichment on the width of annual tree rings, earlywood and latewood, and the area of annual growth of Pinus densiflora Siebold & Zucc. grown in open-top chamber (OTC). To this end, two CO₂ enrichment cases were considered, namely 1.4 × increment (560 ppm in OTC-II) and 1.8 × (720 ppm in OTC-III) were compared with the current atmosphere (400 ppm in OTC-I). The CO₂ enrichment conditions for a period of 12 years (2010-2021) were considered, and all measurements were done through image analysis. The study showed that the increment in CO₂ concentrations positively affected the tree growth. The measurement data from the trees in OTC-III were considerably higher than those from OTC-I, whereas those from OTC-II were slightly higher than those from OTC-I. Decreasing patterns of the measured widths and area in 6-7 years after the beginning of CO₂ enrichment was found for all the OTCs. These patterns were possibly due to changes in the physiological features, such as aging. The findings of the present study can have potential uses as fundamental data for forest management considering CO₂ concentrations.

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.12-20
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• 2008

Radial and vertical variations of relative crystallinity and crystallite width of cellulose within stems of three softwoods (Pinus densiflora S. et Z., P. koraiensis S. et Z, P. rigida Mill.) grown in Korea were examined by an X-ray diffraction method. The mean of relative crystallinity was 61.7% in P. koraiensis, 60.6% in P. densiflora and 49.4% in P. rigida. The degree of crystallinity in earlywood and latewood increased with the age from pith to about 10~15 years, and then remained almost constant value. The relative crystallinitiy of latewood was slightly higher than that of earlywood. The relative crystallinity in P. densiflora was a little lower at the base of stem, but no significant difference by height was shown in P. koraiensis and P. rigida. The crystallite widths in the stems were 2.8 to 3.0 nm, but were not significantly different in earlywood and latewood by height. In conclusion, the relative crystallinity appeared to be a useful index for separating juvenile wood from adult wood in the softwoods of P. densiflora, P. koraiensis, and P. rigida grown in Korea.

• Journal of the Korean Wood Science and Technology
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• v.33 no.1 s.129
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• pp.38-47
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• 2005

Compression, lateral, and opposite woods in a branch of Pinus parviflora S. et Z. were described and compared in the qualitative anatomical aspects through light and scanning electron microscopy. Tracheid transition from earlywood to latewood in the compression wood appeared to be relatively more gradual than in the opposite or lateral wood. Growth ring width and proportion of latewood were thought to be greater in the compression wood than in the lateral or opposite wood. The latewood tracheids of compression wood in transverse surface were mostly round, differently from those of lateral and opposite woods with square to angular shapes. Also, intercellular spaces, helical cavities and checks, and slit-like pit apertures were observed only in the compression wood tracheids. Cross-field pitting in the compression wood appeared not to be used as diagnostic guide because of their severe alteration from normal fenestriform or window-like type to cupressoid to taxodioid types. In tangential surface, fusiform rays in the compression wood were wider but lower than those in the lateral wood or opposite wood. In conclusion, compression wood was different from lateral and opposite woods but lateral and opposite woods were almost identical in qualitative anatomical features.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.295-301
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• 2016

In this study, relationship between seed origin and growth rate of Alnus glutinosa from different seed collection (Yugoslovia, ltaly, United Kingdom, Bulgaria) was investigated with focused on anatomical properties as wood fiber length, vessel element length and diameter. Alnus glutinosa showed diffuse-porous wood with scalariform perforation in alternate pitting. Ray height was 9~11 in tangential section and ray number were 16~26 in cross section. There were no differences on latewood focused on wood fiber length, length and diameter of vessel element, but difference on earlywood. Other than Yugoslavian seed, there was better growth rate with shorter wood fiber and vessel element length on latewood. However, seed from Yugoslovain showed better growth rate with longer wood fiber and vessel element length than other 3 seed orgins.

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.117-126
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• 1997

In fast grown softwood, there are very large changes in material properties going outward from the pith to bark such as anatomical, physical and mechanical characteristics. Some of variations in anatomical properties with annual ring were then examined from Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa, which are major softwoods of plantation in Korea. The large variations of annual ring width during young age of tree tended to stabilize after 25year through the transitional period in 17~23year. The ring density was 1.5~2.4 in 1~10year period, and 3.5~6.3 in 30~35year period, in which juvenile and mature wood were certainly assumed to be formed, respectively. Variations of tracheid length showed functional relationships with annual rings as logarithm. Demarcation between juvenile wood and mature wood could be 16~19year, which was determined from increase rate of tracheid length of 0.2%. Cell wall thickness increased with increase of annual ring even though large variations were observed as well. Variations of cell wall thickness within species were pronounced in latewood than earlywood. The increase of cell wall thickness from juvenile wood to mature wood was predominant in Larix leptolepis as 2.0times, and least in Chamaecyparis obtusa as 1.1 times. Cell diameters showed trends of increase during young age of 1~15year, and consistent afterward. The variations of cell diameter between radial and tangential direction were greater in latewood, and most pronounced in Chamaecyparis obtusa.