• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.237-245
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• 1991

Artificial acid rain (pH 3.0, 4.0 and 5.0) was treated on thd seeds of 5 coniferous species to examine its effects on germination and seedling growth. Artificial acid rain was prepared by diluting sulfuric acid with ground water and ground water(pH 6.5) was used as control. Artificial acid rain was sprayed to seeded pots three times per week. About 5mm of artificial acid rain was treated each time from early April to early October, 1990. Germination, seedling establishment and seedling growth were measured and compared among the treatments. The results were summarized as follows ; 1. Germination, seedling establishment rate of Larix leptolepis and Picea koraiensis were highest on the pH 5.0 plot whereeas those of Abies holophylla and Cryptomeria japonica were highest on the control plot, and those of Abies koreana showed the highest value on the pH 3.0 plot. 2. The differences in seedling height growth of Larix leptolepis was signif- icant at 1% level among the treatment levels of acid rain, whereas those of other species were not significant, Height of Larix leptolepis, Abies koreana and Picea koraiensis were highest on the pH 4.0 plot, and that of Abies holuphylla and Cryptomeria japonica were highest on the pH 5.0 plot. 3. Seedling dry weight of Larix leptolepis and Abies holophylla differed significantly at 1% level among the treatments, but those of other species did not differ. Highest seedling dry weight of Larix leptolepis and Abies koreana were observed on the pH 4.0 plot, and that of Abies holophylla and Cryptomeria japonica did on the pH 3.0 plot, and that of Picea koraiensis did on the control plot. 4. With decrease of pH value of artificial acid rain, the number of injured needle and injured individual tended to be increased, obviously. 5. The differences of soil acidity were highly significant among the treatments for all species.

• Journal of the Korean Wood Science and Technology
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• v.43 no.3
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• pp.381-389
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• 2015

In this study, the effects of moisture content and particles size of ground particles of torrefied larch chips on the pelletizing process were investigated depending on torrefaction conditions ($220^{\circ}C$-50 min, $250^{\circ}C$-50 min, $250^{\circ}C$-120 min). The moisture content in the torrefied chip decreased to 0.69~1.75%, while ash content and calorific value increased compared to untreated chip. In addition, weight loss significantly increased during torrefaction due to hemicellulose degradation. The carbon content in torrefied larch chip increased compare to untreated larch chip, while the hydrogen and oxygen contents decreased. The lignin and glucan contents in torrefied larch chip increased with increasing severity of the torrefaction condition, while hemicellulose decreased. In the particle size distribution of ground particles of torrefied larch chip, larch torrefied at severe conditions was found to produce smaller particles (~1 mm) than that of the larch torrefied at mild conditions. Macropore (over $500{\AA}$) in the torrefied particle was produced during torrefaction. During the pelletizing using ground particles of torrefied larch chip, the pressure needed in pelletizing decreased and pellet length increased with increasing moisture content, regardless of the particle size.

• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.282-291
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• 2010

As compared with existing center-boring timber, skin timber which be hollowed out of its considerable inner parts has some merits as like short drying time, less developed checks during drying, a advantage of lower MC (8~%), more easy injection of chemicals, a possibility of using as a lighter structural heavy timber including Hanok and heavy timber construction, a possibility for the various living necessaries and furniture materials. However, development of hybrid skin timber is required for using as a value-added materials and giving a confidence for the structural safety of skin timber to general user. Thus, improved pine skin timber (IPST) and improved larch skin timber (ILST) were manufactured using the lighter steel plate possible. And compressive capacity of improved skin timber was analyzed. From the results of this study, the following conclusions have been made: 1. Both of IPST and ILST can give a uniformity of material capacity compared with non-treated skin timber. 2. Both IPST and ILST, there was not statistical significancy among the thickness of steel plate. Therefore, it concluded that it was not necessary to use thicker steel plate. 3. There was also not statistical significancy between IPSR and ILST, so it need not to be selective about the species of improved skin timber. 4. IPST showed various failure types, but most failure types of ILST is a splitting type.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.431-440
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• 2005

Location, height and clear-length of individual tree can be measured directly by LiDAR Remote Sensing, and dbh(diameter at breast height) can be estimated indirectly by tree height measured by LiDAR. In addition, stand volume and stand biomass are computed from estimated growth factors. In this study, each estimated growth factor was compared to the field measurements to validate accuracy. The coefficient of determination of total tree heights was 0.66 for total trees, 0.68 for Pinus koraiensis, 0.66 for Larix leptolepis and 0.60 for Quercus spp. The coefficient of determination of clear-length was 0.79 for total trees, 0.73 for Pinus koraiensis, 0.79 for Larix leptolepis, 0.68 for Quercus spp. The coefficient of determination of dbh predicted was 0.73 for Pinus koraiensis, 0.73 for Larix leptolepis and 0.85 for Quercus spp. Moreover The coefficient of determination of basal area was 0.82 for Pinus koraiensis, 0.92 for Larix leptolepis and 0.95 for Quercus spp. Biomass per ha computed by growth factor using LiDAR was 40,306 dm/ha for Pinus koraiensis, 94,150 tdm/ha for Larix leptolepis and 94,481 tdm/ha for Quercus spp. by species.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.1
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• pp.39-44
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• 2012

This study was carried out to determine the relationships between cellulose decomposition and soil environmental factors in larch (Larix leptolepis) and pine (red pine: Pinus densiflora; rigitaeda pine: P. rigida ${\times}$ P. taeda) species planted in the same year (1963). The variation of cellulose mass loss with soil temperature, soil pH, soil $CO_2$ efflux rates, and soil water content was measured monthly for 4 months (July, August, September and October 2006) from three coniferous plantations. Mean mass loss rates during the study period were generally more rapid in rigitaeda pine (6.5 $mg\;g^{-1}\;day^{-1}$) than in red pine (6.2 $mg\;g^{-1}\;day^{-1}$) or larch (6.1 $mg\;g^{-1}\;day^{-1}$) plantations, although the mass loss rates were not significantly different among three tree species (P > 0.05). Cellulose mass loss rates among three tree species were positively correlated with soil temperature (red pine: r = 0.77, P < 0.05; rigitaeda pine: r = 0.59, P < 0.05; larch: r = 0.48, P < 0.05) at the 20 cm soil depth, while the mass loss rates were negatively correlated with soil pH (red pine: r = -0.63, P < 0.05; rigitaeda pine: r = -0.47, P < 0.05; larch: r = -0.43, P < 0.05). There was a significant correlation between cellulose mass loss and soil $CO_2$ efflux rates except for regitaeda pine plantation, while no significant correlation (P > 0.05) between cellulose mass loss and soil water content in larch or rigitaeda pine. The results suggest that cellulose mass loss rates in soil layers depend on the different soil environmental factors caused by tree species.

• Journal of the Korean Wood Science and Technology
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• v.33 no.1 s.129
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• pp.7-16
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• 2005

This study was carried out to evaluate the structural property of double shear bolted connections in Korean Larch. For the main member, sawn lumber and Glulam were used in which thickness of lumber is 39 mm, 89 mm, 139 mm, 189 mm and Glulam 80 mm, 140 mm, 170 mm. For the side member, sawn lumber and steel plate were used in which thickness of lumber is the same of the main member and steel plate is 6mm. And connections were jointed by M12, M16, M20 bolts which were usually used for wood constructions in Korea. Directions of loading to connections were perpendicular and parallel to grain of main and side member. First, through the dowel bearing test, the dowel bearing strength was evaluated and through the bolt bending tests, the bolt bending strength was evaluated. And then experiments for the connection were performed. Obtained results from experiments were compared with calculated values by EYM and analyzed. Strength of double shear bolted connections in Korean Larch was similar or higher than calculated value by EYM. Especially when the side member was made by the sawn lumber, it was similar to the calculated value. In failure mode, the mode was effected by the knot and the dry defect. In the thin main member, it was shown mode I and as the thickness of the main member was thicker, it was changed into mode III.

• Journal of Korean Society of Forest Science
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• v.53 no.1
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• pp.1-26
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• 1981

1. Aiming at supply of basic informations on tree species siting and forest fertilization by understanding of soil properties that are demanded by each tree species through studies of forest soil's morphological, physical and chemical properties in relation to tree growth in our country, the necessary data have been collected in the last 10 years, are quantified according to quantification theory and are analyzed in sccordance with multi-variate analysis. 2. Test species, japanese larch (Larix leptolepis Gord) and the Korean white pine, (pinus koraiensis S et Z.) are plantable in extensive areas from mid to north in the temperate forest zone and are the two most recommended reforestation tree species in Korea. However, their respective site demands are little known and they have been in confusion or considered demanding the same site during reforestation. When the Korean white pine is planted in larch sites, it has shown relatively good growth, but, when Japanese larch is planted in Korean white pine site it can be hardly said that the Japanese Larch growth is good. To understand on such a difference soil factors have been studied so as to see how th soil's morphological, physical and chemical factors affect tree growth helped with the electronic computer. 3. All the stands examined are man-made mature forests. From 294 Japanese larch plots and 259 Korean white pine plots dominant trees are cut as samples and through stem analysis site index is determined. For each site index soil profiles are made in the related forest-land for analysis. Soil samples are taken from each profile horizon and forest-land productivity classification tables are worked out through physical and chemical analyses of the soil samples for each tree species for the study of relationships between physical, chemical and the combined physical/properties of soil and tree growth. 4. In the study of relationships between physical properties of soil and tree growth it is found out that Japanese larch growth is influenced by the following factors in the decreasing order of weight deposit form, soil depth, soil moisture, altitude, relief, soil type, depth a A-horizon, soil consistency, content of organic matter, soil texture, bed rock, gravel content, aspect and slope. For the Korean white pine the influencing factors' order is soil type, soil consistency, bed rock, aspect, depth of A-horizon, soil moisture, altitude, relief, deposit form, soil depth, soil texture, gravel content and slope. 5. In the study of relationships between chemical properties of soil and tree growth it is found out that Japanese larch growth is influenced by the following factors in the order of base saturation, organic matter, CaO, C/N ratio, effective $P_2O_5$, PH, exchangeable, $K_2O$, T-N, MgO, CEC, Total Base and Na. For the Korean white pine the influencing factors' order is effective $P_2O_5$, Total Base, T-N, Na, C/N ratio, PH, CaO, base saturation, organic matter, exchangeable $K_2O$, CEC and MgO. 6. In the study of relationships between the combined physical and chemical properties of soil and tree growth it is found out that Japanese larch growth is influenced by the following factors in the order of soil depth, deposit form, soil moisture, PH, relief, soil type altitude, T-N, soil consistency, effective $P_2O_5$, soil texture, depth of A-horizon, Total Base, exchangeable $K_2O$ and base saturation. For the Korean white pine the influencing factors' order is soil type, soil consistency, aspect, effective $P_2O_5$, depth of A-horizon, exchangeable $K_2O$, soil moisture, Total Base, altitude, soil depth, base saturation, relief, T-N, C/N ratio and deposit form. 7. In the multiple correlation of forest soil's physical properties larch's correlation coefficient for Japanese Larch is 0.9272 and for Korean white pine, 0.8996. With chemical properties larch has 0.7474 and Korean white pine has 0.7365. So, the soil's physical properties are found out more closely related with tree growth than chemical properties. However, this seems due to inadequate expression of soil's chemical factors and it is proved that the chemical properities are not less important than the physical properties. In the multiple correlation of the combined physical and chemical properties consisting of important morphological and physical factors as well as chemical factors of forest soils larch's multiple correlation coefficient is found out to be 0.9434 and for Korean white pine it is 0.9103 leading to the highest correlation. 8. As shown in the partial correlation coefficients Japanese larch needs deeper soil depth than Korean white pine and in the deposit form of colluvial and creeping soils are demanded by the larch. Moderately moist to not moist should be soil moisture and PH should be from 5.5 to 6.1 for the larch. Demands of T-N, soil texture and soil nutrients are higher for the larch than the Korean white pine. Thus, soil depth, deposit form, relief, soil moisture, PH, N, altitude and soil texture are good indicators for species sitings with larch and the Korean white pine while soil type and soil consistency are indicative only limitedly of species sitings due to their wide variations as plantation environments. For the larch siting soil depth, deposit form, relief, soil moisture, pH, soil type, N and soil texture are indicators of good growth and for the Korean white pine they are soil type, soil consistency, effective $P_2O_5$ and exchangeable $K_2O$. In soil nutrients larch has been found out demanding more than the Korean white pine except $K_2O$, which is demanded more by the Korean white pine than Japanese larch generally. 9. Physical properties of soil has been known as affecting tree growth to the greatest extent so far. However, as a result of this study it is proved through computer analysis that chemical properties of soil are not less important factors for tree growth than chemical properties and site demands for the Japanese larch and the Korean white pine that have been uncertain so far could be clarified.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.4
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• pp.189-213
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• 1980

1. Aiming at supply of basic informations on tree species siting and forest fertilization by understanding of soil properties that are demanded by each tree species through studies of forest soil's morphological, physical and chemical properties in relation to tree growth in our country, the necessary data have been collected in the last 10 years, are quantified according to quantification theory and are analyzed in accordance with multi-variate analysis. 2. Test species, larch and the Korean white pine, are plantable in extensive areas from mid to north in the temperate zone and are the two most recommended reforestation tree species in Korea. However, their respective site demands are not known and they have been in confusion or considered demanding the same site during reforestation. When the Korean white pine is planted in larch sites, it has shown relatively good growth. But, when larch is planted in the Korean white pine site it can be hardly said that the larch growth is good. To understand on such a difference soil factors have been studied so as to see how the soil's morphological, physical and chemical factors affect tree growth helped with the electronic computer. 3. All the stands examined are man-made mature forests. From 294 larch plots and 259 white pine plots dominant trees are cut as samples and through stem analysis site index is determined. For each site index soil profiles are made in the related forest-land for analysis. Soil samples are taken from each profile horizon and forest-land productivity classification tables are worked out through physical and chemical analysis of the soil samples for each tree species for the study of relationships between physical, chemical and the combined physical/chemical properties of soil and tree growth. 4. In the study of relationships between physical properties of soil and tree growth it is found out that larch growth is influenced by the following factors in the order of deposit form, soil depth, soil moisture, altitude, relief, soil type, depth of A-horizon, soil consistency content of organic matter soil texture bed rock gravel content aspect and slope. For the Korean white pine the influencing factors' order is soil type, soil consistency bed rock aspect depth of A-horizon soil moisture altitude relief deposit form soil depth soil texture gravel content and slope. 5. In the study of relationships between chemical properties of soil and tree growth it is found out that larch growth is influenced by the following factors in the order of base saturation organic matter CaO C/N ratio, effective $P_2O_5$ PH.exchangeable $K_2O$ T-N MgO C E C Total Base and Na. For the Korean white pine the influencing factors' order is effective $P_2O_5$ Total Base T-N Na C/N ratio PH CaO base saturation organic matter exchangeable $K_2O$ C E C and MgO. 6. In the study of relationships between the combined physical and chemical properties of soil and tree growth it is found out that larch growth is influenced by the following factors in the order of soil depth deposit form soil moisture PH relief soil type altitude T-N soil consistency effective $P_2O_5$ soil texture depth of A-horizon Total Base exchangeable $K_2O$ and base saturation. For the Korean white pine the influencing factors' order is soil type soil consistency aspect effective $P_2O_5$ depth of A-horizon exchangeable $K_2O$ soil moisture Total Base altitude soil depth base saturation relief T-N C/N ratio and deposit from. 7. In the multiple regression of forest soil's physical properties larch's correlation coefficient is 0.9272 and for the Korean white pine it is 0.8996. With chemical properties larch has 0.7474 and the Korean white pine has 0.7365. So, the soil's physical properties are found out more closely related with tree growth than chemical properties. However, this seems due to inadequate expression of soil's chemical factors and it is proved that the chemical properties are not less important than the physical properties. In the multiple regression of the combined physical and chemical properties consisting of important morphological and physical factors as well as chemical factors of forest soils larch's multiple correlation coefficient is found out to be 0.9434 and for the Korean white pine it is 0.9103 leading to the highest correlation. 8. As shown in the partial correlation coefficients larch needs deeper soil depth than the Korean white pine and in the deposit form colluvial and creeping soils are demanded by the larch. Adequately moist to too moist should be soil moisture and PH should be from 5.5 to 6.1 for the larch. Demands of T-N soil texture and soil nutrients are higher for the larch than the Korean white pine. Thus, soil depth, deposit form, relief soil moisture PH N altitude and soil texture are good indicators for species sitings with larch and the Korean white pine while soil type and soil consistency are indicative only limitedly of species sitings due to their wide variation as plantation environments. For larch siting soil depth deposit form relief soil moisture PH soil type N and soil texture are indicators of good growth and for Korean white pine they are soil type soil consistency effective $P_2O_5$ and exchangeable $K_2O$, which is demanded more by the Korean white pine than larch generally. 9. Physical properties of soil has been known as affecting tree growth to greatest extent so far. However, as a result of this study it is proved through computer analysis that chemical properties of soil are not less important factors for tree growth than chemical properties and site demands for larch and the Korean white pine that have been uncertain So far could be clarified.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.578-586
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• 2013

This study was performed in Pinus rigida and Larix kaempferi plantations which occupy approximately 60% of artificial forest area in Korea. The objective of this study was to know the differences in soil physical and chemical properties between both plantations. Soil physical and chemical properties from published literature and analyzed soil data in national forest in 2010 and 2011 were analyzed by plantation regions and stand age of 5 years unit. Jeollanamdo in Pinus rigida plantations and Gyeongsangbuk-do in Larix kaempferi plantations showed higher soil chemical properties than those of other regions. Soil texture in both plantations was almost loam and sandy loam. Mean soil pH in Pinus rigida and Larix kaempferi plantations were 4.86 and 4.87, respectively and there was no relationship between soil pH and stand age. The mean concentrations of total nitrogen (%) and available phosphorus (mg $kg^{-1}$) were 0.21 and 11.00 for Pinus rigida plantation and 0.28 and 13.32 for Larix kaempferi plantation. In Larix kaempferi plantation, total nitrogen, available phosphorus and organic matter concentrations and C.E.C. were higher than those in Pinus rigida plantation and showed positive relationship with stand age. This positive relationship was also revealed between the exchangeable cations and soil pH. The results of this study provide an informative data in selecting tree species for planting and contribute to the establishing forest management plan for the maintenance of sustainable forests resources.

• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.8-19
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• 1989

The proportion of imported wood has been now over 80% of raw materials needed in the wood industry, and therefore, many of studies on the substitution of domestic wood for imported wood and on the increasing the utilization rate of domestic species have been attempted and considered as very important projects to solve. But these trials were practically restricted by several disadvantages of domestic species. such as a small diameter, variety of species, and irregularity of wood physical or chemical characteristics, etc. From a this point of view, this study was carried out to investigate solid wood bending properties of sample trees and then to develop their end uses. The species of sample trees were Pinus densiflora S. et Z., Pinus rigida Mill., and Larix leptolepis Gord. which have large growing stocks but Pinus rigida and Larix leptolepis have not been used well because of their poor qualities. The results obtained were as follows: 1. The optimum conditions for solid wood bending processing of Pinus densiflora, Pinus rigida, and Larix leptolepis are showed in Table 6. 2. The minimum solid-bending radii of Pinus densifjora, Pinus rigida, and Larix ieptolepls were 260mm, 240mm, and 300mm, respectively in steaming treatment.