• KSBB Journal
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• v.23 no.1
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• pp.1-7
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• 2008

The world demand of ethanol as an alternative fuel for gasoline is increasing rapidly because of high oil price and global climate change. Most of ethanol is currently produced from corn grain or sugars in sugarcane and sugar beet. Because these sources compete with foods and animal feed and are not expected to be enough for future demand of ethanol. Thus, cellulosic ethanol from agricultural residues or wood has to be commercialized in near future. Typical cellulosic ethanol production consists of pretreatment, enzyme hydrolysis, fermentation and product separation. This paper reviews the principles and status of each step and discusses issues for cellulosic ethanol production.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.354-365
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• 1993

The purpose of this investigation is to point out the physical fixation and stability of banking slopes of forest roads by invasion of trees. We investigated the situations of sediment discharge and coverage of invaded trees at banking slopes of forest roads. The coverage of invaded trees were calculated from crown injection based on the stable slope and was compared with length of slope, slope gradient, and passage years after construction of forest road. 1. We investigated on the sediment discharge and the invasion of trees at banking slopes, which were actually observed 8 forest roads of Kyonggi-Do and Kangwon-Do. 2. There was no physical stability of the banking slope due to the surface erosion and slope failure, but the tree invasions were active at the stable plots. 3. The length of slope was constructed to 4.0m to 61.0m and recent forest road was mainly constructed to the slopes longer than 30m. There was strong regional effect between the length of slope and the coverage of invaded trees and the above two factors were inversely proportional to each other. 4. There was no significant relationship between the slope gradient and the coverage of invaded trees and the slope constructed within the angle of repose showed the relatively high coverage of invaded trees. 5. There was no significant relationship between the passage years and the coverage of invaded trees in the same investigative region after the construction of forest road. But there was a gradually increasing relationship of tree invasion between above two factors. However, there was some limitation to expect the invasion of the tree species. 6. In the light of the above results, we suggest that the construction of forest road may need foundation work and vegetation work simultaneously for the physical stability to make the environment of tree plantation and that the reasonable increase of construction cost of forest road may be prior to the other factors.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.211-220
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• 1994

The critical need of forest road for enchanting the additional values of various forest products, in addition, giving more recreational opportunity to citizen, has been recognized. In this study the present author aimed to ascertain the most effective construction working plan of forest road being tit to Korean geographic condition. To execute this research program, four locations in national forest of Kangweon-do district and other four locations in private forest in Chollabuk-do district both where forest roads have previously been constructed were selected to analyze the effectiveness basing upon the various factors separately or in combination. The results are summarized as follows ; 1. The investment efficiency in forest road construction showed to increase in the area where terrain factors and district social factors rate is high, and to decrease in the area where forest status factors and forest road structure factors rate is high. So in future the Forest Resource Development Model of forest road should take more importance particularly on those area having terrain factor ratio is low. The extractable value of constructed forest road based on forest status factors rate is expected to increase in case of high considerably. 2. To construct of forest road for increasing multiple use of forests, forest road should be construct with priority on area where obtained total score by evaluation factors is high. And these evaluation factors should take possible determine the position of forest road construction. 3. The following five types of forest road basing upon function performance are suggested with regard to the place where road is constructed. (1) Forest Utilization Model ; where forest status factors and forest road structure factors rate are over 60%. (2) Forest Resource Development Model ; where terrain factors, forest status factors, forest road structure factors and district social factors rate are less than 60%. (3) Community Development Model ; where terrain factors, forest road structure factors and district social factors rate are over 60% but forest status factors rate are less than 60%. (4) Recreation and Health Model ; where terrain factors, forest status factors, forest road structure factors and district social factors rate are over 60%. (5) Multiple Use Model ; where both forest status factors and district social factors rate are over 60%.

• Journal of Korean Society of Forest Science
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• v.26 no.1
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• pp.57-65
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• 1975

This study was carried out to examine the effect of manufacturing factors on physical properties of hardboard (S.I.S) made from the juvenile wood of sycamore (Platanus orientalis L.) The results obtained may be summarized as follows: 1. The difference among the yields of pulp treated with preheat time (defibrate condition) was significant in those of treatments. There was no difference in the yield of pulp treated with defibrate time. The yields of pulp on the tree age classes were shown the difference by 2<4<6<8 years. 2. The specific gravities of hardboard that were treated with hot pressing conditions showed us significantly in those of treatments. There was no difference on the specific gravities among hardboards, treated with resin and wax contents. But in all cases of the specific gravities satisfied the standard which specified the KS F 3203 (Hardboard) 3. The moisture contents of hardboard satisfied the standard which calls for 13-percent below. There were difference in moisture contents between hardboard, treated with preheating time, resin and wax contents and hot pressing conditions. And the moisture contents of hardboard on the tree age classes showed the difference by 2<4<6<8 years. 4. The water absorption and thickness swelling of hardboard treated with defibrations, resin and wax contents, and hot pressing conditions were significant in those of treatments. And the water absorption and thickness swelling of hardboard on the tree age classes showed us the significant difference by 8<6<4<2 years. 5. The difference among the flexural strength in using tested three conditions showed us the difference by defibration$200kg/cm^2$) of hardboard, it is likely to be recommened that the juvenile wood of sycamore is valuable for the raw materials of hardboards.

• Journal of Korean Society of Forest Science
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• v.80 no.3
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• pp.279-286
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• 1991

This study was carried out to investigate relationships between atmospheric $SO_2$ concentration and both soluble sulphur contents in the tree leaves and bark pH to test the possibility of using them as bioindicators for air pollution. Mt. Kwanak, Mt. Nam, Mt. Bukhan (located in Seoul) and Mt. Paldal (located in Suwon, Kyonggi-do) as polluted areas and Pyongchang, Kwangwon-do as an unpolluted area were selected for this study. Soluble sulphur contents in the leaves and hark pH of two tree species (Pines densiflora S. et Z. and Quercus mongolica Fisch.) were analyzed in May, August, and October, 1990 by $BaSO_4$ precipitation method and pH measurement, respectively. In both species, concentration of soluble sulphur in the leaves increased with increasing concentration of atmospheric $SO_2$ (correlation coefficient : 0.52). Soluble sulphur contents in the 2-year-old needles of Pines densiflora (0.170%) and current year leaves of Quercus mongolica (0.081%) in Mt. Nam in the center of Seoul were higher than those in unpolluted Pyongchang area (0.023% and 0.034%, respectively). Bark pH decreased with increasing atmospheric $SO_2$ concentration (correlation coefficient : -0.52). Bark pH of P. densiflora (pH 3.42) and Q. mongolica (pH 3.63) in Mt. Nam were lower than those in Pyongchang area (pH 3.94 and pH 4.93, respectively). Both soluble S content in the leaves and bark pH were recognized as suitable bioindicators for air pollution by $SO_2$. Especially, bark pH showed more sensitive response to air pollution by $SO_2$ than soluble S concentration in the leaves. The lowest concentration of soluble sulphur and the highest bark pH in August were considered to be due to heavy rain during the rainy season. Soluble S content in the leaves and bark pH were not significantly different at 5% level between the two species in polluted areas.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.277-294
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• 2001

This study is aimed to analyze and to evaluate the technology development for sanddune fixation and sandy land conservation in China, resulting from the project of "Studies on the desertification combating and sand industry development". There are various types of sanddunes, including shrub-bunch type, dendritic, honey combed lattice, crescentic, parabolic, pyramid, complex and irregular types, domed, and so on. The height distribution ratios of these sanddunes are 13% of less than 5m, 17% of 6~10m, 18% of 11~25m, 14% of 26~50m, 28% of 51~100m, 10% of more than 100m, and so on. In dry land of China, shifting direction of the sanddune is mainly varying with main direction of wind, but types of shifting sanddunes have many differences in accordance with region, topography, size and shape of sanddunes. The main sanddune fixation technologies could be divided into the bio-ecological measures, physical measures and chemical measures. The bio-ecological measures include such vegetation measures as shrub-grasses measures, sandbreaks between sand dunes, sand fixation shelterblets and establishment of farmland shelterbelts, etc. The physical measures include establishment of high-sanddune stabilization walls and low-sanddune stabilization walls, sanddune fixation levees and coverage method with sediment clay, etc. The chemical measures include fixation-materials spraying and synthetical liquid spraying methods, etc. Besides, irrigation and sand settlement measures, shifting sand trapping channel, ditchsand fixation measures, etc. have been effectively applied.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.58-68
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• 2015

This study compares the wind stability of Larix kaempferi (Lamb.) Carr., Pinus koraiensis Sie. & Zucc. and Abies holophylla Maxim. to understand and inform wind risk management of these plantation trees at Daegwallyeong, Korea. Temporary square plots of $20m{\times}20m$ ($400m^2$) were laid out, and DBH (Diameter at Breast Height) and height for trees greater than 10 cm in DBH were measured by species. A total of 15 plots with 5 plots each in L. kaempferi, P. koraiensis and A. holophylla stands were sampled at random. Among the species, A. holophylla and P. koraiensis have comparatively lower h/d (Height/DBH) ratios than L. kaempferi. These results indicate that the former two species are more wind firm than the latter species. About 9% of the L. kaempferi trees have higher h/d ratios than the critical threshold limit 80. These trees are vulnerable to wind damage and should be removed in the next thinning regime. The analysis of variance detected a significant difference (p < 0.05) in the h/d ratios and Gini coefficient indicating species differences and DBH size variation, respectively. Gini coefficient was 16.4% in A. holophylla, 15.9% in P. koraiensis and 14% in L. kaempferi stands indicating limited DBH size variation. Lower h/d ratios are attributed to thinning in these stands and tree morphological differences. To increase wind firmness, low thinning should concentrate to remove trees with the h/d ratio above 80 coinciding at the time of stand distinction phase. Forest managers and practitioners should measure and maintain h/d ratios of trees below the critical threshold limit of 80 through stand density management. Variable density thinning approach should be tested to increase tree DBH sizes of the even-aged stands.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.474-484
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• 2015

This study aims at providing exercisable basic data for the management of protection areas in China by investigating into their legal system such as current laws, regulations, other relevant laws and international treaties and the management system such as history, classification, organization, personnel, funds and main management work.. In People's Republic of China (1954), several laws have been enacted in succession, such as Environment Law (1989), Regulations of Natural Reserves (1994) and Land Management Methods of Natural Reserves (1995). The development process of China's natural reserves is divided into the following five phases. In the initial phase (1956-1965), about 20 natural reserves were established; in the lag phase (1966-1978), a part of the natural reserves was destroyed under the influence of the Great Cultural Revolution; in the development phase (1979-1998), a normative legal system began to appear after the reform and opening up; in the leap phase (1999-2006), the number of natural reserves increased dramatically; in the stable phase ( 2007-present), the protection and restoration of the ecological environment have been implemented, and the supervision and management have been strengthened. China has established natural reserves of national, provincial, municipal and county levels according to the relevant laws. According to the resource categories, natural reserves can be divided into natural ecosystem reserves, wildlife reserves and natural relic reserves. The Ministry of Forestry is in charge of 1,958 natural reserves which account for 74.2 % of the total natural reserves in China. In China, there are 1,384 natural reserves (52.4 %) for which management institutions have been set up. 1,702 natural reserves (64.47 %) are equipped with management staff, showing a higher ratio than the natural reserves which have set up management institutions. China has established natural reserves of national level, provincial level, municipal level and county level according to law. According to the resource categories, natural reserves can be divided into natural ecosystem reserves, wildlife reserves, and natural relic reserves. The Ministry of Forestry is in charge of 1,958 natural reserves which accounts for 74.2 % of the total natural reserves in China. In China, there are 1,384 natural reserves (52.4 %) which have set up management institutions. 1,702 natural reserves (64.47 %) are equipped with management staff with a higher ratio than the natural reserves which have set up management institutions.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.170-175
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• 2013

This study was conducted to investigate the effect on the habitation of Monochamus alternatus, a vector insect of Pine wood nematode by the tended sound stumps for the developing forestry control methods of Pine wilt disease controls. Field cage plots (1 m ${\times}$ 1 m ${\times}$ 1 m) were established 12 units (Experiment1:4 units, Experiment2:8 Units) and were treated 4 kinds(February in 2010, February, April, June in 2011). The adults of M. alternatus were put into 4~5couples each the cage June in 2011. Presence or absence of the larva entrance holes and larva were detailed November in 2011. The larva were appeared in the sound stumps of sapling and young trees tended at February, April, June, the current emergence year of M. alternatus, but were not appeared in the sound stumps of sapling and young trees tended February in 2010, one year before the emergence of M. alternatus. The larva habitated in stumps of sapling were likely to be smaller in size in compare to the larva in stumps of young trees. In case of young tree, the larva were found at the cleft part of bark, but were not found at ridge part of bark. All observed larva appeared at part of bark and between the bark and the woody parts, but were not found at the woody parts. To develop the control guiding principal of sound stump after forest tending practice, further experiment need is in existence oviposition and larvae of vectors by height of stemps.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.130-140
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• 2020

This study was conducted in order to closely examine about optimum shading for superior seedling production a container seedling of Tetradium daniellii, which is being increased the demand for a seedling due to being used for alternative energy, ecological restoration and honey plant. The experiment of investigating the optimum shading on T. daniellii was carried out by using plastic container types (350 ml/cavity) for the forestry facility cultivation. The shading level was treated with full sunlight and with 35%, 55%, 75% of the full sunlight. As a result of having surveyed height and root collar diameter growth of a containerized seedling in T. daniellii, a case of the shading experiment showed a noticeably high value was indicated in the full sunlight. It was surveyed that the stronger shading level leads to the lower growth value. Root development was most active in full sunlight. Dry matter production, it was investigated to be the highest in full sunlight. It was surveyed to be the similar tendency to the outcome of height and root collar diameter growth. QI, which is index of showing the quality of a seedling, stood at 0.98 in full sunlight, thereby having been investigated to be the highest. As for the chlorophyll content in a seedling, the highest chlorophyll content was indicated in the 75% shading treatment with the relatively highest shading level. The photosynthetic rate and the water use efficiency were surveyed to be the highest in full sunlight with 8.48 μmolCO₂·m^-2s^-1, 1.40 μmolCO₂·mmolm^-1H₂O, respectively. As a result of surveying the whole experiment, optimum shading level for superior seedling production a container seedling of T. daniellii is determined in full sunlight (0%). It is expected that this will be used as a basic data for mass production.