• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.124-138
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• 1992

This study was carried out to estimate long-term demand functions, and to project consumption of roundwood to the year 2030, using time series data for the period 1970-1990. Especially, the unique features of this study are in the estimation of demand functions for roundwood by species group and by end-use with help of dummy variables. It also, attempts to show how dummy variables can be utilized for improving the estimation result. The result of this study reveals that hardwood roundwood consumption is being substituted by softwood roundwood due to the rapid increase in the relative price of softwood, and this trend is expected to continue in the near future. The consumption of roundwood by mining industry is projected to fall as the coal :mining is expected to decline. The parametric estimates of timber demand function by species group and by end-use indicate that the demand for timber in Korea is more responsive to the performance of domestic economy as a whole, represented by GDP in this study, than to other variables such as own and substitute prices. The effects of population growth and substitute prices could not be determined.

• Journal of the Korea Furniture Society
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• v.19 no.6
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• pp.411-419
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• 2008

Xylia xylocarpa is fast-growing trees that are currently planted on trial basis in Sabah, Malaysia. The wood quality of trees grown in Sabah may differ from those grown in other places due to the environmental factors. Five 9-year-old trees of each species were extracted from their respective plots at Luasong, Tawau. Wood specimens were prepared from three height levels; bottom, middle and top, at the inner and outer radial positions. The within-tree and between-tree variations of physical properties of these species were analyzed. The basic density, oven-dry density and green moisture content(MC) are 0.72g/$cm^3$, 0.78g/$cm^3$ and 49.8% respectively. The shrinkage from green to oven-dry conditions for the radial and tangential directions were 3.35% and 5.76%, respectively. The trends of within-tree variations for most properties were more consistent in radial rather than vertical direction. This suggests diameter growth to be a more important factor contributing to the variations compared to height. Samples from the outer part of the stem were found to have higher density, shrinkage and mechanical strengths. The between-trees variations of some wood properties were found to be significantly different, probably due to genetic and micro-environmental factors. Significant correlation was recorded among the physical properties of the species. The true potential of X. xylocarpa for end-uses would be enhanced by further research such as the study on properties of wood from different sites and other properties like durability, seasoning, processing and machining characteristics. The characteristics of X. xylocarpa are comparable to a number of local popular hardwood species, indicating its suitability for heavy construction uses.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.315-325
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• 2020

Boron compound had many advantages as wood preservative, but it was prone to leaching. Improving boron preservation was required to extend the service life of fast growing and low durability red jabon (Antochephalus macrophyllus) hardwood. This study aimed to evaluate the dimensional stability, color change and durability of modified red jabon wood by double impregnation with boron and methyl methacrylate (MMA) and heat treatment. Impregnation I used boric acid or borax, and impregnation II used MMA, while heat treatment used temperatures of 90 ℃ or 180 ℃ for 4 hours. The dimensional stability, leachability, water absorption, color change and decay resistance of modified red jabon wood were tested. The results showed that MMA impregnation increased the dimensional stability of red jabon wood, while the leaching and water absorption in the wood significantly reduced. Heating at 180 ℃ caused less water absorption and higher dimensional stability of the wood than that of heating at 90 ℃. Impregnation with boric acid and MMA followed by heating at 90 ℃ resulted in the highest wood ASE, 89.9%. The color change (∆E^*) of wood increased significantly after MMA impregnation and heating at 180 ℃. Boric acid impregnation caused more resistant wood than borax impregnation against decay fungi and termites. Impregnation with boric acid and MMA followed with heating at 180 ℃ increased significantly the wood resistance against decay fungi and termites.

• Journal of the Korean Wood Science and Technology
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• v.14 no.1
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• pp.55-60
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• 1986

Discoloration sensitivities of woods grown in this country haven't reported yet. Therefore we examined discoloration sensitivities of domestic wood specimens to iron (0.1 %, $FeCl_3.6H_2O$), alkali (pH 12.0, NaOH). acid (pH 1.0, $C_2H_2O_4$) and exposing to sunlight (40 hrs), Thirty-six hardwood species were collected and examined. All specimens were prepared from heartwoods of the collected species. But the specimens of 4 Betula species were divided into sapwoods and heartwoods. By iron stain, the color differences (${\Delta}E$) of 21 wood specimens including one Betula sapwood showed above 12.0, which means strong discoloration sensitivities, and of 3 specimens including one Betula sapwood showed below 2.5, which means weak discolorations. The most strong iron discoloration species was Jungkukgulpi-namu (Pterocarya stenoptera). By alkali stain, the color differences (${\Delta}E$) of 3 wood specimens showed above 9.0, which means strong discoloration sensitivities, and of 18 wood specimens including 4 Berula sapwoods showed below 2.5, which means weak discolorations. By acid stain, the color differences (${\Delta}E$) of 6 wood specimens showed above 10.0 which means strong discoloration sensitivities, and of 12 wood specimens including one Betula sapwoods showed below 2.5, which means weak discolorations. By exposing to sunlight, the color differences (${\Delta}E$) of 31 wood specimens including one Betula sapwoods showed below 6.5, which means, strong discoloration sensitivities, and of only one specimens showed below 2.5, which means weak discoloration. The most strong discoloration species by exposing to sunlight was Guirung-namu (Prunus padus). In general, it was shown that hardwoods grown in Korea were most subject to change of color by exposing to sunlight and next were by iron stain. Domestic hardwoods showed some differences in discoloration sensitivities from domestic softwoods previously reported.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.12-23
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• 1984

This study was carried out to investigate on the catalytic pyrolysis products of hardwood (Alnus hirsuta (Spach) Rupr. Quercus acutissima Carruters, Robinia pseudoacacia L., and Populus tomentaglandulosa T. Lee) and comparing the rate of catalytic pyrolysis from untreated wood (ordinary wood) with that of treated wood with catalizer (Ammonium phosphate, Ammonium sulfate, Ammonium chloride and Urea). The results were summerized as follows; 1) It is the Populus tomentiglandulosa T. Lee that the species has the most content of holocellulose and pentosan. And Populus tomentiglandulosa exhibited high yield of the distillate in pyrolysis products by Ammonium phosphate with catalizer. 2) The distillate of pyrolysis products is decreased in accordance with increasing catalytic concentration. And untreated wood (ordinary wood) with catalizer has the most distillate of pyrolysis products. 3) The yield of charcoal in pyrolysis products is increased in accordance with increasing catalytic concentration and lignin content of species. 4) The caloric values of charcoal in pyrolysis products is decreased with increasing catalytic concentration. And untreated wood (ordinary wood) with catalizer had the most caloric values, but the caloric values of charcoal did not show statistically significent difference at 5% levels in catalizer.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.149-157
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• 2008

We investigated chlorophyll contents and growth performances of five deciduous hardwood species growing in central temperate zone of Korean forest. Cornus controversa, Fraxinus rhynchophylla, Betula schmidtii, Prunus leveilleana, and Acer mono seedlings were grown under four different light intensity regime (full sunlight, $65{\sim}72%$, $29{\sim}40%$, and, $7{\sim}12%$ of the full sunlight) for the experiment. The chlorophyll contents of all of the species were highest in $7{\sim}12%$ of the full sunlight, while lowest under the full sunlight. The relative growth rate of root collar diameter and height were decreased with increasing shading level except for Acer mono that showed the highest relative growth rate under $29{\sim}40%$ of the full sunlight. Total biomass and root volumes of the seedlings studied decreased as the light intensity decreased with different shade levels. For Acer mono, however, the biomass and root volumes were highest in $29{\sim}40%$ of the full sunlight. The relative growth rate of root comparing to shoot decreased as shading increased, and as a result, the ratio of aboveground to belowground biomass increased. As the shading level increased, specific leaf area (SLA), leaf area ratio (LAR), and leaf weight ratio (LWR) of most species increased.

• Journal of Forest and Environmental Science
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• v.15 no.1
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• pp.1-9
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• 1999

Noticing the intrinsic growing habit variations of hardwood species which is indigenous to the natural deciduous forest, eighteen tree species in overstory were selected for comparative evaluating tree form so as to develop the tree form index (TFI). Selected six tree form attributes were arbitrarily divided four assessment criteria and given appropriate scores. Eighteen tree species were undergone corresponding scores, converted to percentage base, and estimated TFI by the summation of the six scoring values. Cluster analysis was carried out to review which attribute would have been shared among species based on dissimilarity of scores for each pair of species in $18{\times}6$ data matrix. The result showed that Populus davidiana had the highest TFI value of 80.8 and Carpinus cordata had the lowest TFI va1ue of 46.3. The species which received more than 70 of TFI are Populus davidiana, Betula costata, Fraxinus mandshurica, and Ulmus davidiana var. japonica, characterized by the advantage of straight and longer bole, the narrower crown, and the thinner branch. On the contrary, such species as Sorbus alnifolia. Prunus sargentii, Acer mandshuricum, Juglans mandshurica, and Carpinus cordata received less than 60 of TFI, characterized by the disadvantage of the crooked or forked stem. the wider or deeper crown. and the thicker branch. In the dendrogram produced by cluster analysis, arbitrary value of Euclidean distance 10 divided eighteen species into four distinctive groups. and the typical characteristics of each group were discussed.

• Journal of Korean Society of Forest Science
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• v.97 no.6
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• pp.597-604
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• 2008

Recognizing the necessity of the development of ecologically sound silvicultural system for the mature Korean pine (Pinus koraiensis), this study was carried out to examine the invasion and growth of understory vegetation after partial cutting. In 1997, the age class VII Korean pine forest in the Experimental Forest of Kangwon National University was opened up about 50% by modified shelterwood cutting with site preparation to induce succeeding regenerations. After 10 years, plenty of hardwood have come to the stand, forming understory vegetation. The abundance and composition of understory vegetation was periodically investigated in the ten $10m{\times}10m$ permanent sample plots, estimating importance values, species diversity index and the distribution of diameter and height of the understory vegetation. Encouraged by canopy opening, the coverage of understory reached perfect closure, composed of 22 tree species and 20 shrub species in 2007. Morus bombycis occupied 29.6% of the total importance value and Cornus controversa was 17.0%, followed by Styrax obassia, Quercus aliena, Quercus mongolica, Acer mono, and Pinus koraiensis. In the year of 2000 the species diversity was highest as 2.547 with 26 tree species and deceasing thereafter, showing 2.220 with 22 tree species in 2007. As understory layer was thickly covered and got grow bigger, some shade intolerant species were disappeared, lowering species diversity. In 2007 the biggest tree was a Quercus aliena with 11.3 cm of DBH and the tallest tree was a Cornus controversa with 9.8m of height. The frequency distribution of number of trees by diameter and height classes formed the inverted-J-shaped curve, supposed to be typical uneven-aged stand.

• Journal of Korean Society of Forest Science
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• v.83 no.4
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• pp.429-440
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• 1994

This study attempt to evaluate the recreation space(two patterns ; one is open space ; forest, water-front space and free open space, the other recreational fercilities) located in the natural area based on clarifying the relationship between the physical conditions of these spaces and human response(users' cognitive evaluation and users' activity pattern). On this standpoint it was proceeded to analyses of the information which was collected by interviews to users who were in this open space at the natural park of Osaka Prefecture. Through this study, the results were summarized as follows ; 1) Forest and waterfront space are considered to be a basic factor of the composition in natural recreation areas. There was difference on the recreational value depending on condition of forest composition. The hardwood-forest apparently high in its efficiency. 2) Free open space is a definite recreational space surely wide in its scope of active of recreational use. The site should be setted up considering the plants conditions around and geographical features according to the recreational activities, and the ground cover should be well controlled. 3) The recreational facilities in natural settings such as the sightseeing tower, the insect display hall, and the camp site appeared to produce low value as a recreational space. It was desirable that recreational activities be allowed within the scope. Consequently, we should carefully consider environmental capacity and landscape to designing these spaces 4) Traditional history and cultural properties are recognized as part of recreational resource as and also as essence of the compositions. So continuos care and proportion of history and cultural properties should be guaranteed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.2
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• pp.110-115
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• 2003

The iufluence of abandonment of agricultural fields on soil carbon and nitrogen dynamics is rarely addressed due to lack of appropriately paired sites. In this study, we identified three sites that have native forest and abandoned rice and crop fields at Mt. Kumdan near Seoul. Currently the vegetation of indigenous forest and the abandoned rice field is deciduous hardwood forest, while that of the abandoned crop field is deciduous shrub. We measured soil $CO_2$ evolution and inorganic N availability for the three sites from 25 July 2002 through 24 January 2003. Soil $CO_2$ evolution tracked seasonal soil temperature. Mean soil $CO_2$ evolution (g $CO_2$/$m^2$/hr) for the study period was 0.42 for the rice field to forest, 0.50 for the crop field to shrub, and 0.41 for the indigenous forest, respectively. Soil $CO_2$ evolution and soil temperature were not different among the sites; however, soil water content was significantly different. Soil water content had a very weak influence on soil $CO_2$ evolution. Inorganic resin N availability differed among the three sites and seemed to be related to soil moisture.