• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.31-38
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• 1999

This paper deals with a coating technique of hardening surface layer of softwood{Larix leptolepis) flooring board to improve its surface properties such as hardness and abrasion resisitance without spoiling its exellent qualities such as beautiful color tones and great strength. For surface hardening of the wood, polyurethane wood sealer was used as under coat, polyurethane sanding sealer as intermediate coat, and UV-curing epoxy acrylate and urethane acrylate varnishes as top coat. The hardness of the wood was improved by the coating treatment and it was similar to that of high density hardwood such as oak, keruing. The abrasion resistance of the coated wood was greatly improved by UV curing epoxy acrylate or urethane acrylate varnishes. Adhesion properties and impact resisitance of the coated wood surface were also good. It was suggested that the well-coated larch wood could be used as interior flooring board as substitute for hardwood such as keruing.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.369-375
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• 2017

In this study, it was intended to compare the two methodologies for forest management project through extension of rotation age: Korean Forest Carbon Offset Standard (KFOS) and Verified Carbon Standard (VCS). The amount of carbon removals and offset credits based on the two methodologies and their trends were analyzed in this study. The major difference between two methodologies were found at the process of estimation of baseline carbon removals. For instance, average carbon stock during the project period was used for estimation of baseline carbon removals in KFOS, while average carbon stock change during the 100 years was used in VCS. Due to the different approach for estimation of baseline carbon removal, the estimated offset credits were also different according to the two methodologies. In this study, 15 project scenarios were considered for comparison of two methodologies : 5 major coniferous stands in Korea (Pinus densiflora in Gangwon region, Pinus densiflora in Central region, Pinus koraiensis, Larix leptolepis, Chamaecyparis obtusa) with 3 project periods (30, 35, 40 years). The results showed that estimated carbon offset credits based on the KFOS methodology were higher for all 15 scenarios compared to those based on the VCS methodology. The KFOS showed a steep decline in the annual offset credit as project period gets longer, thus it is not desirable for projects with longer period. VCS is more acceptable for longer projects with a small difference according to the project periods. The results also indicated that Pinus densiflora in Gangwon, Pinus koraiensis, and Larix leptolepis are more desirable species for forest management project through the extension of ration age.

• The Korean Journal of Mycology
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• v.15 no.1
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• pp.48-69
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• 1987

To understand host ranges and host specificity of ectomycorrhizal fungi and fungus specificity of host tree species, higher fungi from pure forest stands of following twelve tree species were collected for six years from 1981 to 1986: Pinus densiflora, P. rigida, P. koraiensis, Picea koraiensis, Larix leptolepis, Abies holophylla, Populus $alba{\times}glandulosa$, Castanea crenata, Quercus aliena, Q. acutissima, Q. mongolica, and Betula platyphylla. A total of 196 ectomycorrhizal species with 8 varieties in 48 genera were identified. Thirty-one species with one variety belonged to Russula, 22 species with 5 varieties to Amanita, 18 species with one variety to Lactarius. Fungi belonging to above three gepera, Laccaria, and Cantharellus had a relatively wide host range. Laccaria laccata was collected under all the 12 tree species, Amanita vaginata group under 11 tree species, Laccaria amethystina and Russula foetens under 10 tree species, Lactarius gerardii and Russula sororia under 9 tree species, and Amanita agglutinata, Cantharellus cibarius, Russula bella, and R. virescens under 8 tree species. Above 10 fungal species may be classified to have a wide host range. Following fungi were collected under 4 to 5 tree species of both conifers and broad-leaved trees: Amanita citrina, Boletus bicolor, B. erythropus, Lactarius piperatus, L. subzonar­ius, and Russula pseudodelica. Above fungi may be classified to have an intermediate host range. Chroogomphus, Gomphidius, Rhizopogon, and Suillus were collected only under Pinaceae and may be classified to have a narrow host range. Particularly Suillus grevillei was collected only under Larix leptolepis, and appeared to have high host specificity. A total of 83 ectomycorrhizal species were collected under Abies holophylla, 66 species under Pinus densiflora, 50 species under Pinus rigida, 49 species under Pinus koraiensis, 46 species under Quercus aliena, and 23 fungal species under Larix leptolepis. Particularly, Larix leptolepis was associated with different fungal flora, with fewer species of Amanita, Lactarius and Russula, and more species of Laccaria. Most host tree species surveyerl in the present study appeared to have low fungus specificity for ectomycorrhizal formation.

• Journal of agriculture & life science
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• v.43 no.3
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• pp.15-26
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• 2009

This study was undertaken to determine inhibitory compounds from extracts of the softwood (larix leptolepis, Pseudotsuga menziesii) sawdust against Trichoderma spp. The sawdust of L. leptolepis and P. menziesii were hot water extracted, which were with fraction extracted organic solvents. The organic solvent extractions were carried out by n-hexane, methylene chloride, ethyl acetate. The antifungal activity of hot water extracts of L. leptolepis sawdust was determined to be 20.6% inhibition at a concentration of 1,000 ppm against Trichoderma spp. The antifungal activity of P. menziesii sawdust was outstanding about 60.3% against Trichoderma spp. The yields of the fractions of n-hexane soluble, methylene chloride soluble and ethyl acetate soluble from the hot water extract of L. leptolepis sawdust were 4.0%, 6.0% and 8.0%, repectively. However, the yields of the fractions of three solvents of P. menziesii sawdust were 8.0%, 13.0 and 14.0% correspondingly. The antifungal activity of n-hexane soluble fraction from hot water extracts of L. leptolepis sawdust was highest to about 68.5% to 79.9% against Trichoderma spp. compared to others. The antifungal activities of n-hexane soluble fraction from hot water extracts of P. menziesii sawdust showed 68.5%, 71.4%. 71.9%, 75.7% and 82.3% against T. aggressivum, T. atroviride, T. harzianum, T. koningii and T.viride, respectively. The n-hexane soluble fraction revealed much higher antifungal activity than the other fractions did. This study demonstrated that the n-hexane fraction of the hot water extracts of L. leptolepis and P. menziesii exhibited the greatest antifungal activity against Trichoderma spp.

• Journal of the Korean Wood Science and Technology
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• v.30 no.3
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• pp.109-115
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• 2002

Mycelial growth of L. edodes by pretreatments of softwood was studied on a sawdust medium. The sawdust used was from the following softwood species : Larix leptolepis, Pinus densiflora and Pinus koraiensis. The pretreatment consisted of cold-water (48 h), hot-water (3 h) and steam extractions (3 h) at a ratio of 500 g : 3,000 mL (sawdust : distilled water). The sawdust medium was a mixture of 76% sawdust, 20% rice bran, 3% glucose, 0.4% potassium nitrate and 0.6% calcium carbonate. Following sawdust pretreatments proved most suitable : L. leptolepis (steam extraction), P. densiflora (hot-water extraction) and P. koraiensis (hot-water extraction). Mycelial growth on P. koraiensis sawdust increased in proportion to an increase in hot-water extraction time. Mycelial growth was optimum on the sawdust extracted for 12 hours, hot-water extraction beyond this period proved unsuitable. With the exception of P. densiflora at 100 ㎍/mL, antifungal activity occurred in every sample. Maximum inhibition of mycelial growth was obtained from following concentration of hot-water extractives : P. densiflora (10⁴ ㎍/mL) and P. koraiensis (10⁴ ㎍/mL). This study has provided useful preliminary information for the cultivation of L. edodes.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.548-557
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• 2001

This study was carried out to classify forest vegetation of Mt. Myeonsan with phytosociological analysis of ZM School and to explain community types with CCA ordination. The research sites were located in the northern part of Kyungsangpook-Do area and in the southern part of Kangwon-Do. The 73 plots were investigated in the study areas which were including 291 plant species. The forest vegetation was classified into Quercus mongolica community group, Juglans mandshurica community group, and Larix leptolepis plantation. Q. mongolica community group was divided into 9 communities such as Rhododendron schlippenbachii community, Symplocos paniculata community, Pinus densiflora community, Betula schmidtii community, Fraxinus rhynchophylla community, Populus davidiana community, Tilia amurensis community, Betula costata community and Betula davurica community. J. mandshurica community group was divided into 5 communities and 4 groups such as Acer mono community (subdivided into Quercus serrata group and typical group), Fraxinus mandshurica community, Ulmus laciniata community (subdivided into typical group and Ribes mandshuricum group), Malus baccata community and Carpinus laxiflora community. And it was entirely classified into 17 vegetation units. According to CCA, Q. mongolica community group showed high positive correlation to topography, altitude and slope degree, and J. mandshurica community group showed high positive correlation to bare rock. However, L. leptolepis community group was not significantly ordinated with the gradient of environmental factors. And in correlation of axes, important environmental variables were topography and altitude.

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.23-31
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• 1988

A total of 320 Larix leptocepzs Trees growing in Kyonggi and Kangwon Province were examined to estimate tree volume and height with DBH and age. The criteria of selecting the "best" regression equation were based on coefficient of determination, $R^2$, adjusted standard error, I, and the ease of application. From the results obtained in this study, the method of estimating tree volume and height with DBH and age showed the following advantages ; 1. Since no measurement of tree height is needed, it saves time and labor in forest survey. 2. It has the ease of application because age is determined directly in artificial forests. 3. Volume and height can be estimated more easily and accurately with DBH and age than other methods.

• Journal of the Korean Wood Science and Technology
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• v.12 no.3
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• pp.25-34
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• 1984

This experiment was carried out to investigate the effects of monosaccharides extracted by saturated portland cement solution on the cement setting in comparision with the inhibitory index (I) of each lignocellulosic-cement system. The wood species which have been widely reforested in Korea, Populus alba-grandulosa, Larix leptolepis, Abies holophylla, Pinus koraiensis, Pinus rigida, Pinus densiflora and agricultural wastes of rice husk and rice stalk were used at this study. The wood meal, 0.50g on dry weight basis, through 0.83 mm(20 mesh) and retained on 0.35mm (40 mesh) screen was extracted by 25 ml saturated portland cement solution and the pH of saturated portland cement solution Was 12.7. To eliminate cation exsisting in the extracted solution, the cation exchange column was used (Fig. 4). Afterwards the extracted monosaccharides were reduced into alditols with sodium borohydride and analyzed by the gas-liquid chromatography for xylan, mannan, arabinan, galactan, gluean. The heat of cement hydration for lignocellulosic-cement system was measured in Dewar flask (Fig. 2). And then the inhibitory indices were calculated from maximum hydration temperature, time and maximum slops of hydration curve of ligno cellulosic-cement systems. The results obtained were as follows; (1) The inhibitory index of pines-Pinus rigida (I=29.33) and Pinus densiflora (I=35.76), were lower than that of poplar-Populus alba-glandulosa (I=41.48), and the index of Larix ieptoiepis (I=73.00) was the highest among eight lignocellulosic-cement systems, and accordingly both Pinus rigida and Pinus des(flora were seemed to be good wood species for wood-cement composite manufacture. (2) In case of Pinus rigida, the inhibitory index was 29.33 and the ratio of the hexoses to the pemoses was 6.04 and in case of Larix leptolepis, the index and the ratio were 73.00 and 35.19, respectively. Therefore the inhibitory index increased with increasing the ratios of the hexoses to the pentoses. (3) The richer amount of xylose and mannose in species caused decreasing the slops of the hydration curve of the lignocellulosic-cement system, prohahly due to the chemical adsorption of the acetyl groups in the hemicellulose on the surface of cement grains. (4) The amoun of xylose and mannose were significant to the inhibitory index of each lignocellulosic-cement system but any specific relation between the amount of glucose and inhibitory index was not found.

• Journal of the Korean Wood Science and Technology
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• v.24 no.4
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• pp.1-6
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• 1996

Extracts from bark have been studied with a view to producing water-proof wood adhesives. Lately many softwoods, such as radiata pine from New Zealand and larch from Siberia, Russia, have been imported and utilized, and their residual barks would be expecting as potential raw materials for something useful chemicals. The great effort toward utilization of bark extractives as a chemical feedstock has been made on a worldwide level. However few report has been done for the utilization of tree bark extractives in Korea. Hot-water extracts were prepared from barks of Japanese larch(Larix leptolepis). Siberian larch(Larix gmelinii) and Radiata pine(Pinus radiata). The effect of various factors, such as particle size, liquor ratio, extraction temperature, and reaction time, on the extractive yields was discussed. Particle sizes affected the hot-water extractives: the finer the particle size, the higher extractives and extract efficiency. Higher temperature and higher liquor ratio were more effective. Extractives from Japanese larch were relatively less than those from Siberian larch and Radiata pine barks. Formaldehyde precipitates was the highest in extractives of Radiata pine barks. It could be concluded that Siberian larch bark was the best raw material for tannin adhesives, because its extractive yield was higher than those of the other barks.

• Journal of the Korean Wood Science and Technology
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• v.23 no.3
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• pp.16-22
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• 1995

The profiles of the heating temperature in three water vat temperatures (55, 66 and 77$^{\circ}C$) and the cooling temperature under the average ambient temperature of 3$^{\circ}C$ in 4 and 10cm depths from surface at the center of veneer bolts length showed similar patterns for Japanese larch (Larix leptolepis). Dahurian larch (Larix gmelinei) and Radiata pine (Pinus radiata). The difference of these core temperatures of 10cm depth from surface varied proportionally with the increase of vat temperatures. The average heating time based on final core temperature of 6$^{\circ}C$ lower than vat temperature required about 14.5 hours in vat temperature of 55$^{\circ}C$ and 13.5 hours in vat temperature of 66and 77$^{\circ}C$. Each internal temperature of 4 and 10cm depths from surface started to decrease from the beginning of cooling and after about two hours.