• Resources Recycling
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• v.15 no.1 s.69
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• pp.3-11
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• 2006

Fast pyrolysis of Quercus acutissima was carried out in a fluidized bed pyrolyser and then the physicochemical properities of obtained bio-oil were analyzed using GC/MS. The yields of bio-oil of Quercus acutissima and Larix leptolepis from a fluidized bed pyrolyzer were maximized at $350^{\circ}C\;and\;400^{\circ}C$, respectively. This is due to the difference or cellulose content between the two tree species. Above the optimum temperature, the yields of char and oil decreased as the reaction temperature increased, but the yield of gas-phase and water fraction increased. It is concluded that this phenomenon is occured by secondary pyrolysis in the free board. The feeding rate of the sample in a fluidized bed pyrolyser did not affect the yields and composition of products, because of a sufficient mixing between bed materials and sand.

• Journal of the Korean Wood Science and Technology
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• v.17 no.1
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• pp.55-68
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• 1989

This experiment was carried out to investigate the crack of coated Nitrocellulose Lacquer on flatand edge-grained boards of Quercus acutissima, ring-porous wood, and Betula platyphylla var. japonica, diffuse-porous wood, by variations of moisture contents at 7, 13 and 21%. Cold check system was used as an accelerating method for crack development, in which one cycle of the system consisted of 10 replications of each unit cycle, $60^{\circ}C$ for 4hr followdd by $-20^{\circ}C$ for 4hr. The analysis of Nitrocellulose Lacquer characteristics was made by means of water permeation measurement, F.T.I.R. spectroscopy, N.M.R. spectroscopy, gel permeation chromatography, gas chromatography, and D.S.C. The results obtained were as follows: 1. The number of cracks increased with the increasing moisture content of board. 2. The crack of coated film on flat-grained board was fewer in number than on edge-grained board. 3. The crack occurred in Quercus acutissima was more numerous on edge-grained board but less frequent on flat-grained board compared with that in Betula platyphylla var. japonica, respectively. 4. The cold crack vertically developed to the grain both in Quercus acutissima and Betula platyphylla var. japonica. 5. Water permeability in intermediate coated film was lower than in under and top coated film, but the difference was not confirmed between under and top coated film.

• Journal of Forest and Environmental Science
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• v.33 no.4
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• pp.342-347
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• 2017

Since the first report of the oak wilt disease at 2004 in Korea, the disease distributed over Korean peninsula and are still giving severe damages. The management of oak wilt disease in Korea has mainly focused on the control of insect vector, Platypus koryoensis. Neverthless the effective method for evaluating the pathogenicity of the pathogen, Raffaelea quercus-mongolicae (Rqm), and for screening chemical or biological agents with strong inhibitory activity against the pathogen, is absolutely necessary, an reliable method is not available so far. This study was conducted to develop the effective method for evaluating the pathogenicity of Rqm in oak trees. The culture suspensions of Rqm were artificially injected to the saplings of Quercus acutissima by using ChemJet tree injector. Three months after treatments, the treated saplings were cut and dipped into 1% fuchsin acid solution. There were significant differences in non-conductive area (%), discoloration area (%) and vertical discoloration length between the pathogen-injected and distilled water-injected control treatments. These results indicated that the pathogen is the causal agent for the dysfunction of water conductive tissue, which will finally result in wilt symptom. Re-isolation of the pathogen and PCR detection using specific primers for the pathogen also confirmed the presence of Rqm in the sapwood chips of the pathogen-injected saplings. These observations would be greatly applied to other related researches for evaluating the pathogenicity of tree wilt pathogens and biocontrol efficacy of the selected antagonistic microorganisms, in case that the wilt symptom is not easily shown by artificial inoculation of the causal agent.

• The Korean Journal of Ecology
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• v.28 no.4
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• pp.207-214
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• 2005

The present study was undertaken to classify and describe the Quercus spp. forests in the lower montane zone of Mts. Bakdal, Gyemyeong, Boryeon, Worak, Cheondeung, Joryeong, Gungmang, Buyong and Sirubong in Chungbuk Province, Korea using the methodology of the Z.-M. school's phytosociology. The Ouercus spp. forests were classified into three communities and two groups; A. Quercus variabilis community A-1. Quercus serrata-Quercus acutissima group, A-2. Quercus mongolica group; B. Quercus mongolica-Rhododendron schlippenbachii community; C. Quercus dentate-Chloranthus japonicus community. These vegetation units were arranged by human interference and a gradient of environmental complex such as altitudes, and also were corresponded relatively well with a result of cluster analysis (UPGMA) based on the dominance of component species.

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.142-149
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• 2014

This study has compared carbon storages, annual carbon uptakes and annual soil respiration by planting type in Dujeong park, Cheonan city. Four plantations were selected in Dujeong park: Pinus densiflora plantation, Quercus acutissima community, Quercus acutissima-Robinia pseudoacacia plantation, and Robinia pseudoacacia plantation. We investigated each plantations from February 2012 to March 2013. Carbon storage and annual carbon uptake in each plantations were calculated with allometric method (Lee, 2003), and soil respiration was measured by using LI-6400 (LI-COR). Carbon storages in Pinus densiflora plantation, Quercus acutissima community, Quercus acutissima-Robinia pseudoacacia plantation, and Robinia pseudoacacia plantation were $17.36tonCha^{-1}$, $88.63tonCha^{-1}$, $115.38tonCha^{-1}$ and 4$9.88tonCha^{-1}$, and annual carbon uptakes were $1.04tonCha^{-1}yr^{-1}$, $2.12tonCha^{-1}yr^{-1}$, $6.47tonCha^{-1}yr^{-1}$ and $3.67tonCha^{-1}yr^{-1}$, respectively. Average annual carbon uptakes per tree of Pinus densiflora plantation, Quercus acutissima community and Robinia pseudoacacia plantation were $1.81kgC{\cdot}treeyr^{-1}$, $17.86kgC{\cdot}treeyr^{-1}$ and $9.14kgC{\cdot}treeyr^{-1}$ and Quercus acutissima was the greatest. The amounts of carbon released from soil respiration in the same four plantations were $2.20{\mu}molCO_2m^{-2}s^{-1}$, $1.90{\mu}molCO_2m^{-2}s^{-1}$, $2.47{\mu}molCO_2m^{-2}s^{-1}$ and $2.51{\mu}molCO_2m^{-2}s^{-1}$, and annual soil respiration were estimated $6.66tonCha^{-1}yr^{-1}$, $5.33tonCha^{-1}yr^{-1}$, $7.20tonCha^{-1}yr^{-1}$ and $7.25tonCha^{-1}yr^{-1}$, respectively. In this study area, Quercus acutissima-Robinia pseudoacacia plantation has a significant contribution to the role of carbon sink. However, the contribution of Pinus densiflora plantation was evaluated less. The results of this study can be used as the necessary data for tree planting and management in urban park.

• Journal of the Korean Society of Safety
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• v.26 no.4
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• pp.111-119
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• 2011

This study was designed to provide basic data applicable to fire investigation through consideration of combustion products and propose vulnerability of combustibles through analysis of $CO_2$ emission. In order to achieve these research objectives, characteristics of combustion products such as smoke release rate of each part(raw leaves, branches and barks), $CO_2$ emission and ash production were considered targeting on 6 oak species(Quercus variabilis Blume, Quercus aliena Blume, Quercus serrata, Quercus mongolica Fisch, Quercus dentata Sapling and Quercus acutissima) using cone calorimeter and smoke density tester. As a result, it was found that raw leaves release smoke more relatively than branches and barks, when they burn, and that Quercus variabilis Blume has the highest smoke density. Also, Quercus acutissima released CO and $CO_2$ which are respectively, 6.67 times and 1.43 times more than Quercus variabilis Blume with low $CO_2$ emission. In addition, branches released CO and $CO_2$ more relatively. There was a big difference in ash production among raw leaves(3.1 g), branches(10.5 g) and barks(16.43 g). It was identified that Quercus serrata produces ashes which are nearly 9.95 times more than Quercus variabilis Blume. It demonstrates that Quercus serrata contains relatively higher minerals and that Quercus variabilis Blume can leave lots of traces like stain and carbonization, as it releases smoke a lot and it's difficult to predict visibility, when a forest fire breaks out in its community area. It is also considered that smoke particles containing oil in the air leave strain on the surface of a tree, and that CO and $CO_2$ emission increases, when crown fire to burn branches breaks out.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.1
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• pp.57-74
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• 2022

Seed zones were constructed using temperature and precipitation data for the Korean Peninsula and were described as 65 zones. Seed zones for South Korea were reclassified, and they were classified into 34 districts. This study was conducted to define the spread of 5 native seed species (Pinus densiflora, Quercus acutissima, Quercus variabilis, Acer pictum, Carpinus tschonoskii) by linking the seed zones with MaxEnt. The emergence point of native seeds was acquired through the 1:5,000 Forest Type Map and the 4th national natural environment survey data. Based on the MaxEnt result, regions with a habitat probability of 0.5 or more were extracted and overlapped with seed zones to identify the native seed habitat. After analyzing the climate regions with high habitat density, regions with high habitat density of native seeds for each administrative district were identified. In the case of Pinus densiflora, Quercus acutissima, and Quercus variabilis, the Winter minimum temperature(WMT) -9.4~-6.6℃, Annual Heat:Moisture(AH:M) 19~24℃/m was 37%, 43%, and 34%, respectively. occupied the largest area. In Acer pictum, WMT -6.6~-3.8℃ and AH:M 16~19℃/m accounted for 42% of the area, and Carpinus tschonoskii had WMT -3.8~-1.1℃, AH:M <16℃/m Districts accounted for the largest area at 33%. The regions with high density of Pinus densiflora, Quercus acutissima, and Quercus variabilis by administrative district were distributed in high density in Seoul, Southern Gyeonggi-do, Chungcheong-do, and Gyeongsangbuk-do. Acer pictum was distributed in high density in Jeolla-do and Gyeongsang-do, and Carpinus tschonoskii in Jeju, Jeollanam-do and Gyeongsangnam-do. Through this study, seed zones for each of the 5 native seeds were established, and it is expected to provide basic data for the management of native seeds.

• The Korean Journal of Ecology
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• v.10 no.1
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• pp.43-51
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• 1987

The forest vegetation of Jongyeoul hill, Seoul, was classified into six secondary forests and two plantations by ZM method; Pinus densiflora, Quercus acutissima, Pinus rigida, Robinia pseudoacacia and Alnus hirsuta-Quercus mongolica community, and Castanea crenata and Pinus koraiensis plantation. In the herb layer the species richness and total coverage of deciduous broad leaf forests showed higher values than those of evergreen needle leaf forests. The peak in July at Q. acutissima forest and in the middle of June at R. pseudoacacia forest. Simpson's diversity index(Ds) in different stands are as follows: Ds>0.6 in R. pseudoacacia forest, Ds=0.3~0.6 in Q. acutissima forest and Ds<0.3 in P. densiflora and P. rigida forest. It is found that, although dominance rank and importance value were originated from different school each other, two measures can be used exchangablym showing almost linear positive correlation between them in this study.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.74-81
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• 2012

Decay rate and nutrient dynamics during leaf litter decomposition of deciduous Quercus acutissima and evergreen Quercus mysinaefolia were studied for 24 months from December 2008 to December 2010 in Gongju, Chungnam Province, Korea. Percent remaining weight of Q. acutissima and Q. mysinaefolia leaf litter after 24 months elapsed was $46.3{\pm}5.4%$ and $37.8{\pm}2.5%$, respectively. Decomposition of evergreen Q. mysinaefolia leaf litter was significantly faster than that of deciduous Quercus acutissima leaf litter. Decay constant(k) of Q. acutissima and Q. mysinaefolia leaf litter after 24 months elapsed was 0.38 and 0.49, respectively. Initial C/N and C/P ratio of Q. mysinaefolia leaf litter was significantly lower than those of Q. acutissima leaf litter. Initial C/N and C/P ratio of Q. acutissima leaf litter was 46.8 and 270.9, respectively. After 24 months elapsed, C/N and C/P ratio of decomposing Q. acutissima leaf litter decreased to 22.5 and 104.2, respectively. Initial C/N and C/P ratio of Q. mysinaefolia leaf litter was 22.4 and 41.7, respectively. After 24 months elapsed, C/N and C/P ratio of decomposing Q. mysinaefolia leaf litter decreased to 16.7 and 89.7, respectively. Initial concentration of N, P, K, Ca and Mg in leaf litter was 8.31, 0.44, 4.18, 9.38, 1.37 mg/g in Q. acutissima, and 19.88, 2.73, 7.06, 8.24, 2.61 mg/g in Q. mysinaefolia, respectively. Initial concentration of N and P in Q. mysinaefolia leaf litter was significantly higher than those in Q. acutissima. After 24 month elapsed, remaining N, P, K, Ca and Mg were 100.91, 114.75, 32.99, 50.63, 15.51% in Q. acutissima, and 43.22, 11.35, 12.98, 82.22, 44.23% in Q. mysinaefolia, respectively. N and P in decomposing leaf litter was immobilized in Q. acutissima, and mineralized in Q. mysinaefolia.

• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.20-26
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• 1998

The objective of this study was to determine the rate of nitrogen mineralization and nitrification in a mature sawtooth oak(Quercus acutissima $C_{ARRUTH}$) stand in the Chungbu Forest Experiment Station, Kyonggi Province. Nitrogen mineralization and nitrification in the top 15cm of mineral soil were examined from November 1995 to November 1996 using an in situ buried bag method. Net nitrogen mineralization was 95.2mg/kg/yr and nitrification was 65.4mg/kg/yr. Nitrification consisted of 69% of annual nitrogen mineralization. Neither nitrogen mineralization nor nitrification was significantly correlated with the monthly soil temperature and soil moisture content.