• Journal of Korean Society of Forest Science
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• v.97 no.4
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• pp.368-373
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• 2008

The objectives of this study were to validate existing growth models of Pinus densiflora and Larix leptolepis grown in Chonbuk regions, and to examine suitability of models to different regions using spatially varied data set. In the valuating model predicted of Pinus densiflora, except to DBH growth model, basal area and height prediction models were biased to fit to different region. And in the valuating predicted height, basal area and DBH model of Larix leptolepis, they were adequate to new data set acquired from different region. Therefore, existing prediction models, except DBH model, of Pinus densiflora have the limitation of practicality that could not be suitable for application to different region. However, owing to high compatibility shown predicted DBH, basal area and height models of Larix leptolepis, they will be adequate to use as the prediction models where data are available around eastern mountain areas of Jeollabukdo.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.60-68
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• 2003

In forest products industry, a variety of nondestructive evaluation techniques are now being used to assess the mechanical properties of structural lumber. Ultrasonic and longitudinal vibration technique are frequently used to assess the modulus of elasticity(MOE) of lumber. The objective of this research was to evaluate the MOE and modulus of rupture(MOR) of small-diameter of Larix log(Larix kaempferi Carr.), using these techniques. In this study, 50 small-diameter logs were nondestructiveively evaluated. The dynamic modulus of elasticity(Eu) of the logs was first evaluated, using an ultrasonic method. After ultrasonic tests, the logs were measured using a longitudinal vibration technique(Ev). Static bending test was then performed on the logs to obtain the static modulus of elasticity(Es) and modulus of rupture of these logs. In general, the dynamic MOE (Ev) of logs was closely co..elated with the stati, MOE for log. Based on the results of these experiments, it can be concluded that small-diameter Larix logs can be successfully evaluated by Ultrasonic and longitudinal vibration technique. The experimental results indicated that the ultrasonic technique is effective to the log, which contains many knots. The longitudinal vibration technique is effective to the log, in which many cracks are included.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.41-50
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• 2002

Small clear specimens of Quercus acutissima Carr. and Larix caempferi Carr. were used to measure shrinkage and thermal conductivity for the reasonable and effective use. All samples were conditioned to 18, 12, 5% moisture contents in a humidity chamber of 86, 66, 20% relative humidity(RH), respectively and room temperature(23℃) All specimens were conducted on the shrinkage and thermal conductivity test at each MCs. These processes(cycle) were repeated three times. The radial and tangential shrinkages of Quercus acutissima Carr. and Larix caempferi Carr. decreased at each level of MCs, with the increasing cycles. The radial and tangential shrinkages increased as the specific gravity(on oven-dry weight and volume basis) increased. Thermal conductivities of the radial and tangential direction of Quercus acutissima Carr. and Larix caempferi Carr. increased at each levels of MCs, with increasing cycles. Good correlations were obtained between shrinkages and thermal conductivities of radial and tangential direction, and specific gravity (on oven-dry weight and oven-dry volume basis) and MC.

• Journal of the Korea Furniture Society
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• v.19 no.1
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• pp.75-82
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• 2008

A series of the studies on the applied physical properties of main domestic species have been conducted last three years. Equilibrium moisture content(EMC) of Pinus koraiensis, Larix kaemferi, Pinus koraiensis were investigated. The experiments for sorption property were conducted with 20- and 80-mesh wood powder and resulted in their EMC's at various sorption conditions. Amount of moisture sorption and sorption speed of Larix kaemferi were shown the most large values and very fast among three Korean main coniferous wood.

• Journal of the Korea Furniture Society
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• v.27 no.4
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• pp.302-308
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• 2016

It has been known that acetylation improves the dimensional stability of wood. Liquid phase acetylation is more popular than gas-phase acetylation for the effectiveness of weight gain of wood. In this study the specimens of domestic red and Korean pines are acetylated in liquid phase and their physical properties, such as density, bending strength, anti-hygroscopicity etc., are analyzed. Acetylation increases the average weights and volume of larch specimens by 11.4% and 3.4%, respectively, and their average oven-dry densities are increased by $0.03g/cm^3$. Acetylation does not influence on Modulus of Rupture (MOR) and Modulus of Elasticity (MOE). The average Percentage Reduction in Hygroscopicity (PRH) and average Percentage Reduction in Water soaking (PRW) of larch specimens are respectively 20.2% and 20.8%. Thus it can be concluded that acetylation improves the dimensional stability of larch specimens.

• Journal of Forest and Environmental Science
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• v.31 no.3
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• pp.202-206
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• 2015

Site index curves were developed for Larix kaempferi and Pinus koraiensis in Gangwon and North Gyeongsang provinces in Korea. For the development of site index, Schumacher and Chapman-Richards model were applied using the data collected from 2012 to 2014. Base age was set to 40 years for Larix kaempferi and Pinus koraiensis in site index of this study. Coefficient of determination and root mean square error of site index models were provided by species, and the models were compared with the previous studies to check the suitability. Overall, site index models developed in this study fitted in the current data well. Thus, the site indexes are considered to be properly used in Gangwon and North Gyeongsang provinces.

• The Korean Journal of Ecology
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• v.20 no.4
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• pp.259-264
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• 1997

To determine patterns of nitrogen (N) and phosphorus (P) change in foliage and twig we collected branch samples of 40-year-old Pinus rigida and Larix leptolepis plantations every month during the growing season of 1996 in Yangpyeong, Kyonggi-Do. Significant seasonal differences on N and P concentrations in foliage and twig were observed for both study species because of nutrient retranslocation. P. rigida and L. leptolepis retranslocated 40 and 37% of foliar N and 86 and 16% of foliar P, respectively. Twig N and P retranslocation rates of P. rigida and L. leptolepis were 114 and 25%, and 42 and 70%, respectively. There were no significant differences in foliar N retranslocation rates between P. rigida and L. leptolepis while P retranslocation rate in foliage of P. rigida was higher than that of L. leptolepis. Our results suggested that twigs were the main sinks for retranslocated nutrients from foliages of the both study species.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.188-190
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• 2000

We explored changes in soil nitrogen (N) availability in a thinned (control, light, moderate, and heavy thinning) Larix leptolepis plantation determined by using ion exchange resin bags. Nitrogen availability varied among measurement periods, however, total available N (ammonium plus nitrate) concentrations did not change significantly in the 1 year since thinning. We found higher N availability in summer and fall than in winter.

• Journal of the Korea Furniture Society
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• v.17 no.4
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• pp.101-107
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• 2006

To know the structural difference between the ray parenchyma and ray tracheid among Pinus densiflora, Pinus rigida, Pinus koraiensis and Larix kaempferi, an observation was carried out under the FE-SEM. The longest ray parenchyma and ray tracheid were found in Pinus koraiensis species while the shortest ray tracheid and ray parenchyma were found in Pinus densiflora and Larix kaempferi. Larix kaempferi had more than one endwall pit in its ray parenchyma. Pinus densiflora was found highest in the pit aperture diameter in ray tracheid and aperture diameter in the cross-field pit. The pit border width in ray tracheid and lumen diameter of ray parenchyma were found highest in Pinus rigida. The cell wall thickness of ray parenchyma and pit aperture diameter in endwall pit of ray tracheid were found highest in Pinus koraiensis compared to other species.

• Journal of the Korea Furniture Society
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• v.13 no.2
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• pp.11-18
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• 2002

This study was carried out to investigate the strength and technical feasibility of glulam from small diameter Pinus densiflora and Larix kaempferi. Small diameter logs are currently not used in structural laminated beam construction, but it is suggested that its properties may be feasible for this purpose. The glulam combinations were designed with high grade laminae located at outer laminations (face) and low grade laminae located at center laminations. Important problems of finger jointed glulam as a structural beam are the small modulus of rupture (MOR). One solution for this problem Mi to use veneer and solid wood as the face laminae. The MOE values were predicted for each beam from laminae. The results showed that actual beam MOE values exceeded slightly the predicted values. Based on the evaluation and analysis of Pinus and Larix glulam, the maximum load of Larix kaempferi glulam indicated large values. The bending properties of A and E types glulam were superior to others. It is suggested that this small diameter log can be a candidate for structural glulam construction, providing the proper combinations of face laminae.