• Journal of the Korean Wood Science and Technology
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• 제52권2호
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• pp.191-203
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• 2024

Persimmon wood (Diospyros kaki) is a seasonal fruit-producing plant with a beautiful dark pattern in its wood that is suitable for high-quality furniture, sculptures and musical instruments. The utilization of persimmon wood can be improved by determining its anatomical characteristics, such as juvenile and mature wood. This study aimed to determine the boundaries between juvenile and mature wood and observe the anatomical properties of juvenile and mature wood and their variations in the axial direction. Three 30-year-old persimmon (D. kaki) trees grown in Karo, North Sumatra, Indonesia, were used in this study. The boundary between juvenile and mature wood was determined by measuring the fiber length and vessel element length from near the pith to near the bark. Anatomical observations were conducted in the juvenile and mature wood areas. The results showed that the average boundaries between juvenile and mature wood were 44.11 mm from the pith and were not significantly different in the axial direction of the trees. Furthermore, the wood anatomy categories of juvenile and mature wood differed significantly in terms of fiber diameter, fiber proportion, vessel proportion, and axial parenchyma proportion. In the axial direction, vessel diameter, ray parenchyma frequency, and ray parenchyma proportion at the base, middle, and top of the tree were significantly different.

• Journal of the Korean Wood Science and Technology
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• 제33권2호통권130호
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• pp.17-23
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• 2005

Juvenile and transitional-juvenile wood samples from loblolly pine (Pinus taeda) were immersed in water to investigate longitudinal and tangential swelling properties. Increment cores from twenty-six loblolly pine trees were sampled at breast height (1.37 m). Earlywood rings 5 and 9 were separated from the core, extracted, oven-dried and immersed in water at room temperature. The variance in longitudinal swell was significant for ring 5 compared to ring 9 (p = 0.001). It was found that tangential swell might predict longitudinal swelling of juvenile wood at ring 9 but not at ring 5. Poor correlation in ring 5 suggests that swelling response in younger juvenile wood may differ. The swell response at ring 5 did not follow the shrinkage models discussed in the literature while ring 9 adhered to the expected curve.

• 한국가구학회지
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• 제17권3호
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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 the Korean Wood Science and Technology
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• 제10권1호
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• pp.38-46
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• 1982

우리나라의 주요(主要)한 조림수종(造林樹種)이고 경제적수종(經濟的樹種)인 잣나무조림목(造林木)에 대(對)하여 여러 재질지표치(材質指標値)의 수간내(樹幹內)에서의 재질변동(材質變動)의 규칙성(規則性)에 의(依)하여 미성열재(未成熟材)와 성숙재(成熟材)와의 구분(區分) 성숙재(成熟材)와 미성숙재(未成熟材)의 범위(範位)의 표현(表現) 및 양재부(兩材部)의 재질(材質)의 특징등(特徵等)을 조사검토(調査檢討)하였으며 그것을 요약(要約)하면 다음과 같다. 1) 각종재질지표치(各種材質指標値) 즉(卽) 연륜폭(年輪幅) 만재율(晩材率) 가도관장 가관세포의 절선방향(切線方向)의 폭(幅) 및 막후(膜厚) micro fibril의 경사각(傾斜角) 용적밀도수(容積密度數)의 수간내변동(樹幹內變動)의 일반경향(一般傾向)을 구명(究明)하고 이 결과(結果)로부터 성숙재(成熟材)와 미성숙재(未成熟材)와의 구분(區分)의 가능성(可能性)을 검토(檢討)하였다. 2) 미성숙재(未成熟材)의 범위(範圍)는 잣나무조림목(稠林木)에 있어서는 일반적(一般的)으로 수심을 중심(中心)으로 하여 반경(半徑) 6~11cm 정도(程度)의 원통형(圓筒形)으로 표시(表示)할 수 있다. 3) 미성숙재(未成熟材)의 수심으로부터의 연륜수(年輪數)는 12~20 연륜정도(年輪程度)이며 생장환경(生長環境)이 비슷한 임지(林地)의 각(各) 개체내(個體內)에서는 같은 경향(傾向)을 가진다. 4) 성숙재(成熟材)가 출현(出現)하는 한계(限界)의 지상고(地上高)는 5~10m 정도(程度)이다. 5) 미성숙재(未成熟材)의 연륜수(年輪數)는 각(各) 입본(立本)의 생장경과(生長經過)에 따라 차이(差異)가 생기며 일반적(一般的)으로 생장(生長)이 균일(均一)할때는 원통형(圓筒形)을 나타낸다. 6) 미성숙재(未成熟材)의 재질변동(材質變動)은 성숙재(成熟材)의 재질변동(材質變動)보다 일반적(一般的)으로 큰 경향(傾向)을 나타내고 있다.

• Journal of the Korean Wood Science and Technology
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• 제21권2호
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• pp.73-80
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• 1993

Pinus koraiensis is one of the most important reforestation species which had widely been planted around the country. Therefore, there are great research needs on the fundamental properties of wood to extend the frequency of uses and adequate availabilities. Research results on the characteristics of anatomical wood properties and changes are summarized as follows: 1. At a horizontal direction of tree trunk, the tracheid length at outer wood gradually becomes shorter as it reaches to pith. The tracheid length having between 32 and 42 annual rings showed over 2.5 times longer than that of pith, and also its length increases from the bottom to the top of the stem. 2. The tracheid diameters in latewood showed a little fluctuations, and the shortest near to the pith in earlywood. The tracheid diameters in earlywood are more than 2 times those of latewood, and the differences between the mature and juvenile wood in earlywood are less than 10${\mu}m$. 3. The tracheid wall thickness in early wood showed a little fluctuations. On the contrary, tracheid wall thickness in latewood rapidly increases from the pith to the bark. The tracheid wall of mature wood showed 10 to 20% thicker than that of juvenile wood. 4. The fibril angle at the secondary walls of tracheid within an annual ring showed higher degree in earlywood than that of latewood. The highest tracheid fibril angle was observed at around the pith of both earlywood and latewood. Then, fibril angle slowly decreased toward outer wood, and was stabilized after 15 years. 5. Structural boundaries between mature and juvenile wood from Pinus koraiensis are divided by 13 to 19 annual ring and distance of 5 to 8cm from the pith.

• Journal of the Korean Wood Science and Technology
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• 제26권4호
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• pp.20-25
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• 1998

Radial variation of crystalline state in a stem of Chamaecyparis obtusa E. was examined by x-ray diffraction analyses. Relative crystallinity and degree of crystallite orientation showed significant differences between juvenile and adult wood. That is, Relative crystallinity increased with increasing the age from pith to about 20th annual ring, after which it reached a more or less constant value. On the other hand, degree of crystallite orientation decreased outward from pith to about 10 years and presented almost a constant value thereafter. Crystal width by Scherrer's equation did not show any significant differences between juvenile and adult wood. Therefore, it was considered that crystallinity index and degree of crystallite orientation by x-ray diffraction method could be used for evaluating wood quality.

• Journal of the Korean Wood Science and Technology
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• 제46권4호
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• pp.323-337
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• 2018

Merkusii pine wood (Pinus merkusii) was extensively planted throughout Indonesia, where it is only indigenous in northern Sumatera, by the Dutch during colonial times. The demand for this wood species, especially in the domestic market, has increased notably, despite its limited durability regarding decay resistance. The purpose of this study was to investigate the occurrence of juvenile and mature wood on merkusii pine and to analyze its radial features from pith to bark based on density, shrinkage, static bending in modulus of rupture and modulus of elasticity, fiber length, microfibril angle, and durability. A segmented modeling approach was used to find the juvenile-mature transition. The graveyard test was performed to characterize the termite resistance from pith to bark of merkusii pine. The maturations were estimated to start at radial increments of 15 cm from the pith by fiber length and of 12 cm from the pith by microfibril angle. The projected figures for the proportion of juvenile wood at breast height were around 65%. The results also indicate that the pine wood was $0.52g/cm^3$ in density, 1.45 in coefficient of anisotropy, which indicates its good stability, 7597 MPa in modulus of elasticity, and 63 MPa in modulus of rupture. Natural durability against subterranean termite of the merkusii pine wood was rated to be grade 4 to 0 from pith to bark. However, after being treated by Entiblu and Enborer preservatives, its rating increased to grade 10 to 9.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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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.

• Journal of the Korean Wood Science and Technology
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• 제21권3호
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• pp.45-52
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• 1993

Surveyed results on the slope of grain and the twist of sawn lumber of Pinus koraiensis, Larix leptolepis, and Pinus densiflora were summarized as follows: 1. The slope of grain of Pinus koraiensis has a Z-grain in the stem axis. The slope of grain was found to be the lowest at near to the pith and then constantly increased. At the height of 0.2m from the base of stem. a cross section of 35 annual rings was found to have a repeatedly increasing and decreasing slope of grain and then constantly decreased. At the height of 1.2m to 7.2m from the base of stem, the slope of grain increased conspicuously until the 10th annual ring, after which it increased near to the bark with repeatedly increasing and decreasing trends. 2. Pinus densiflora has a S-grain in the stem axis. The lowest slope of grain was found at near to the pith, and the highest in the 10 to 35 annual rings from the pith. 3. Larix leptolepis has a S-grain. At the height of 3.2m from the base of stem, the big fluctuation of the slope of grain was found without any particular trend. 4. The slope of grain and the twist between natural and reforested timber of Pinus koraiensis were found to be almost the same trend in viewpoint of the annual ring. The maximum slope of grain of imported Siberian timber of Pinus koraiensis was found at the 10 annual rings, which was quite similar to that of native species in Korea, but the big difference of the twist was found at 140 annual rings. 5. The twist was little at the mature wood of reforested Pinus koraiensis and Siberians and the duplicated part of mature and juvenile woods of those. On the contrary, the twist was great at the duplicated part of mature and juvenile woods of Pinus koraiensis. 6. The twist of Larix leptolepis showed the S-direction which coincided with that of slope of grain. The twist was greatest at the part of juvenile wood and little at the duplicated part of mature and juvenile woods, and little difference of twist was found between mature and juvenile woods. 7. Siberian larix having a minimum slope of grain showed the lowest twist, and the twist at the duplicated part of mature and juvenile woods showed a middle level of both mature and juvenile woods' portions.

• Journal of the Korean Wood Science and Technology
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• 제34권1호
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• pp.1-6
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• 2006

국내에 가장 많이 조림된 수종이고 중요한 국산 목재자원인 잣나무와 일본잎갈나무 두 수종의 재질특성을 구명하기 위하여 수지구와 에피델리얼세포의 수간내 변이성을 조사하였다. 그 결과, 두 수종 간에 수직수지구의 수와 그 수의 방사방향 변이성에 차이가 있었다. 일본잎갈나무의 수평수지구의 직경 및 에피델리얼세포 수도 방사방향으로 변이성을 나타냈다. 즉 미성숙재부와 성숙재부간에 수지구와 에피델리얼 세포의 출현특성이 차이가 있었다. 결론적으로, 잣나무와 일본잎갈나무에 있어서 수지구와 에피델리얼세포의 출현특성을 성숙재부와 미성숙재부로 구분하는 재질지표로 이용할 수 있을 것으로 생각하였다.