• The Korean Journal of Ecology
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• v.27 no.2
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• pp.87-92
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• 2004

Soil respiration rate was measured from March to November 2003 using the KOH absorption method in Pinus densiflora, Quercus variabilis, Platycarya strobilacea stands in Jinju, Gyeongnam Province. Throughout the study period, average soil temperature and moisture content were 16.2$^{\circ}C$, 25.1% for P. densiflora stand, 17.1$^{\circ}C$, 24.3% for Q. variabilis stand, and 17.6$^{\circ}C$, 25.1% for P. strobilacea stand, respectively. The seasonal fluctuations of soil respiration rate increasing in summer and decreasing in winter, which there were strong positive correlations of soil respiration and soil temperature in all study stands. However, there were no significant correlations between soil moisture and soil respiration. Soil respiration rates throughout the study period ranged from 0.12 to 0.77 for P. densiflora stand, 0.23 to 1.37 for Q. valiabilis stand, and 0.30 to 1.47 g $CO_2\cdotm^{-2}\cdothr^{ -1}$ for P. strobilacea stand, respectively. Mean soil respiration rates in P. densiflora, Q. variabilis, P. strobilacea stands were 0.43, 0.80, and 0.90 g $CO_2\cdotm^{-2}\cdothr^{ -1}$, respectively. The Q$_{10}$ values were 2.38 for P. densiflora stand, 2.11 for Q. variabilis stand, and 2.07 for P. strobilacea stand. Annual total soil respiration was 24 for P. densiflora stand, 49.3 for Q. variabilis stand, and 55.3 t $CO_2\cdotha^{-1}\cdotyr^{ -1}$ for P. strobilacea stand, respectively.y.

• The Korean Journal of Ecology
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• v.11 no.3
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• pp.109-122
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• 1988

The foret vegetations of Daedunsan provincial park area in Korea were classified into eight communities of Acer mono-Zelkova serrata, Lindera erythrocarpa-Cornus controversa, Carpinus tschonoskii, Quercus variabilis, Quercus serrata, Carpinus laxiflora, Rhododendron schlippenbachii-Quercus mongolica and Rhododendron mucronu-latum-Pinus densiflora by the Z-M method. By two dimensional analysis of temperature, moisture gradients, the eight communities were grouped into four vegetation types: cove forest dominated with Zelkova serrata and Cornus controversa, hornbeam forest with Carpinus tschonoskii and Carpinus laxiflora, oak forest with Quercus variabilis, Quercus mongolica, Carpinus laxiflora, Carpinus tschonoskii, Zelkova serrta and Pinus densiflora community was made from the analysis of actual vegetation map by the phytosociological classification, environmental conditions and human interferences.

• The Korean Journal of Ecology
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• v.11 no.3
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• pp.131-136
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• 1988

The continuum analyses and polar ordinations were applied for the ordination of forest vegetation in Mt. Naejang, national park in Korea. In the continuum analyses the sequence of Pinus densiflora, Quercus mongolica, Quercus variabilis, Carpinus laxiflora, Carpinus tschonoskii, Lindera erythrocapa and Zelkova serrata community was arranged along the continuum gradient as in moisture gradient analyses. The positive correlation of r=0.83 between continuum index and soil moisture content was observed. In the polar ordinations ten communities of Pinus densiflora, Quercus monogolica, Quercus variabilis, Carpinus laxiflora, Daphniphyllum macropodum, carpinus tschonoskii, Quercus aliena-Carpinus tschonoskii, Torreya nucifera, Cornus controversa-Lindera erythrocarpa and Zelkova serrata were identified. However, continuous distribution pattern of ten communities mentioned above could be regarded as a vegetational continuum. The results of these ordinations also were corresponded to those of phytosociological classification.

• Korean Journal of Environment and Ecology
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• v.9 no.1
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• pp.30-41
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• 1995

Vegetational structure were investigated for evergreen broad-leaved forest in (Mt.) Pulgapsan. Forty plots were classified into five groups, which were Aphananthe aspera community, Neolitesea sericea -Aphananthe aspera - Torreya nucifera community, deciduous broad-leaved forest group. Quercus aliena community, Quercus aliena - Quercus variabilis community by the TWINSPAN and DCA ordination techniques. But the vegetation of (Mt.)Pulgapsan was seem to be unstable structure of seral stage. Neolitsea sericea showed positive correlation to Aphananthe aspera and negative correlation to Quercus aliena. Quercus variabilis, Garpinus tschonoskii.

• Journal of Plant Biology
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• v.27 no.2
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• pp.95-103
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• 1984

The Populus maximowiczii dominated forest of the Sangcheon ravine, Mt. Seolag, is distributed in the area with the conglemerates substrate, along the ravine stream from 170m to 550m in altitude. Toward the both slopes of the northern and southern peak from the stream side, the zonal distribution of vegetation was recognized; P. maximowiczii forest of Pinus densiflora forest and deciduous broad leaved forest. The pure community of P. maximowiczii with even more 80-98% in relative basal area (aspen basal area/basal area) was found in the ravine area from 360m to 420m in altitude, the optimal ranges in the species and community by two dimensional ordination with thermal and xeric cline axis. The species compete with Pinus densiflora, in the ravine stream side, and with deciduous broad leaved tree species such as Fraxinus rhynchophylla, Prunus sargentii, Lindera obtusiloba, in the mountain slope sides. On the other hand, the ravine vegetation, including the aspen forest, was classified into Pinus densiflora, Pinus densiflora-Carpinus laxiflora, Pinus densiflora-Populus maximowiczii, jessoensis, Acer mono-Fraxinus rhynchophylla, Carpinus laxiflora-Quercus mongolica, Quercus variabilis-Quercus ariena, Quercus ariena, Quercus variabilis-Stephanandra incisa, Picrasma quassioides-Celtis sinensis, Betula davurica-Zanthoxylum schinifolium and Styrax obassia-Lindera obtusiloba association.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.429-439
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• 2013

This study was conducted to determine the changes of the ecological niche breadth and niche overlap of Quercus acutissima and Quercus variabilis under elevated $CO_2$ concentrations and under elevated temperature conditions. We investigated the growth responses by environmental factor, $CO_2$ concentration, air temperature, light, soil moisture and nutrients. Rising $CO_2$ concentration was treated with 1.6 times than control (ambient) and increased temperature with $2.2^{\circ}C$ above the control (ambient) in the glass greenhouse. Ecological niche breadth and niche overlap was calculated the two oak species (Q. acutissima and Q. variabilis), which were cultivated with light, soil moisture and nutrient gradients at four levels. As a result, the ecological niche breadth of Quercus acutissima was determined to be increased under the warming treatment, but decreased under soil moisture and nutrient environments. The ecological niche breadth of Quercus variabilis was increased under light, soil moisture and nutrients of the warming treatment than control. Ecological niche overlap between Quercus acutissima-Quercus variabilis was increased under light of the warming treatment than control, but decreased under soil moisture and nutrient environments. These results means that two oak species are more severe competition in light environments than soil moisture and nutrient environments. According to analyses of the Cluster and PCA, the two oak species were more sensitive react under light environment than to elevated $CO_2$ concentration or elevated temperature.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.85-90
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• 2010

In this study, we have examined the monthly combustion characteristics of Quercus variabilis, a representing Quercus Spp. in Korea, using its living leaves over the period of from June to October. As a result, we were able to identify that their moisture content was about 114%~155%. The leaves of Quercus variabilis collected in October showed the lowest moisture content and nonflaming ignition temperature. The leaves of July showed the fastest flaming ignition time of 27s while those from September showed the longest persistence of flame with 105s, and also showed the highest total heat release amount. There was a noticeable difference in each month of the above period regarding total heat release amount and total smoke release amount with a gradual increase from June to October. The maximum smoke density was a bit higher in October leaves but there was no significant monthly difference. In addition, July leaves were shown to reach the maximum value in the shortest time of 795s.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.5
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• pp.47-56
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• 2023

The Quercus variabilis and Quercus dentata, which are said to be relatively drought tolerant among the important genus Quercus that represent deciduous broad-leaved forests in Korea. These two species are widely distributed worldwide in Korea, Japan and China (northern, central, western and eastern subtropical regions). This study compared the ecological niche breadth and overlap according to growth response in 4 soil moisture gradients for the two species and tried to reveal degree of competition and ecological niche characteristics. The ecological niche breadth was 0.977±0.020 for Q. variabilis and 0.979±0.014 for Q. dentata, the latter being slightly wider. And they were similar in 5 traits (stem length, leaf lamina length, leaf width length, stem weight, leaf petiole weight), Q. variabilis was more dominant in 4 traits (leaves number, stem diameter, leaf area, leaf petiole length), and Q. dentata was more dominant in 7 traits (root length, shoot length, plant weight, root weight, shoot weight, leaf weight, leaf petiole weight). The ecological niche overlap for soil moisture between the two species overlapped most in plant structure-related traits and least in photosynthetic organ-related traits such as petiole length. As a result of principal component analysis, degree of competition between the two species for soil moisture was more severe when the soil moisture condition was low than high. Among the measured traits that affect the two-dimensional distribution, 8 traits (Leaves number, Shoot length, Stem length, Plant weight, Root weight, Shoot weight, Stem weight, Leaves weight) were correlated with the factor 1, and 2 traits (Leaf width length, Leaf petiole weight) were correlated with the factor 2 (r>0.5). These results show that the ecological response of the two species to soil moisture is not a few traits involved, but several traits are involved simultaneously.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.96-101
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• 2010

One of the restriction of wood as building material is its combustibility. The purpose of this paper is to examine the combustion properties of the quercus variabilis and zelkova serrata which are dried at room temperature and meet the desirable characteristics for use of construction materials. The cone calorimeter (ISO 5660-1) was used to determine the heat release rate (HRR) and fire smoke index, as well as CO production and smoke obscuration. The $HRR_{mean}$ 77.94 kW/$m^2$ of the quercus variabilis at 50 kW/$m^2$ was high in comparison with $HRR_{mean}$ 13.06 kW/$m^2$ for the zelkova serrata. Furthermore, the quercus variabilis has high specific extinction area ($SEA_{mean}$), 41.11 $m^2$/kg compared with $SEA_{mean}$ 9.23 $m^2$/kg of zelkova serrata. Thease results are depend on the density of tested wood species. In addition, the quercus variabilis has high CO production rate compared with that of zelkova serrata. Also, zelkova serrata showed an increase of retardant properties attributed to char formation compared with that of quercus variabilis.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.599-605
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• 2012

The purpose of this study is to estimate diameter distribution, volume per hectare, and carbon stock for Quercus variabilis stand. 354 Quercus variabilis stands were selected on the basis of age and structure, the data and samples for these stands are collected. For the prediction of diameter distribution, Weibull model was applied and for the estimation of the parameters, a simplified method-of-moments was applied. To verify the accuracy of estimates, models were developed using 80% of the total data and validation was done on the remaining 20%. For the verification of the model, the fitness index, the root mean square error, and Kolmogorov-Smirnov statistics were used. The fitness index of the site index, height, and volume equation estimated from verification procedure were 0.967, 0.727, and 0.988 respectively and the root mean square error were 2.763, 1.817, and 0.007 respectively. The Kolmogorov-Smirnov test applied to Weibull function resulted in 75%. From the models developed in this research, the estimated volume and above-ground carbon stock were derived as $188.69m^3/ha$, 90.30 tC/ha when site index and stem number of 50-years-old Quercus variabilis stand show 14 and 697 respectively. The results obtained from this study may provide useful information about the growth of broad-leaf species and prediction of carbon stock for Quercus variabilis stand.