• Journal of Ecology and Environment
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• v.33 no.4
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• pp.343-349
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• 2010

In Korea, man-caused forest fires are known originate primarily in coniferous forests. We have hypothesized that the vulnerability of Pinus densiflora forests is principally a consequence of the ignition characteristics of the species. To assess this hypothesis, we conducted two combustion experiments using fallen leaves with a reference species, Quercus variabilis. In the first experiments, in which a cigarette was employed as a primary heat source for the initiation of a forest fire, the Pinus leaves caught fire significantly faster (1'1" at Pinus, 1'31" at Quercus, P < 0.001), and ignition proceeded normally. Quercus leaves, on the other hand, caught fire but did not ignite successfully. In the second set of experiments utilizing different moisture contents and fuel loads, the maximum flame temperature of the Pinus leaves was significantly higher ($421^{\circ}C$ at Pinus, $361^{\circ}C$ at Quercus, P < 0.001) and the combustion persisted for longer than in the Quercus leaves (8'8" at Pinus, 3'38" at Quercus, P < 0.001). The moisture contents of the leaves appeared to be a more important factor in the maximum temperature achieved, whereas the most important factor in burning time was the amount of fuel. Overall, these results support the assumption that Pinus leaves can be ignited even by low-heat sources such as cigarettes. Additionally, once ignited, Pinus leaves burn at a relatively high flame temperature and burn for a prolonged period, thus raising the possibility of frequent fire occurrences and spread into crown fires in forests of P. densiflora.

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.540-561
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• 2011

We carried out a study for ecological management and ideal vegetation structure selection on the shrine forest of 'Miwhang-sa' considering the species diversity and the vegetation structure analysis associated with global warming. We carried out the analyses of phytosociological vegetation structure, correlation between vegetation units and environmental variables, life form, species diversity, and species evenness. This study identified the vegetation units as 3 communities. The identified vegetation units are as follows: Quercus acuta community(DQ), Quercus serrata-Quercus variabilis community(QQ) and Celtis sinensis community(CS). According to the basis on the environmental variables; Ca, Mg and P, Celtis sinensis community and other communities were classified. Quecus serrata-Quercus variabilis comm. and Quercus acuta comm. were classified, according to the basis on the environmental variables; organic matter(OM), Ni and Zn. Sasa borealis as life form R1-2, dominated the herb layer and will dominate the herb and shrub layers. Species simplification is formed on herb layer and will be formed on shrub layer. The species diversity of Quercus serrata-Quercus variabilis community is higher than the one of Quercus acuta community, and the species diversity of shrine forest around Miwhang-sa was higher than the shrine forest around Nameun-sa where evergreen broad-leaved forests dominate. It is essential that the long-term vegetation management considering the vegetation units by phytosociological analysis, the species simplification problem of low layers by S. borealis and the species diversity and evenness in the shrine forest, Miwhang-sa.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.3
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• pp.27-40
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• 1991

For the establishment of district planning in natural parks, vegetationin the most significant point. Consequently, district plan should be made basically under phytosociological investigations. The purpose of this paper is to conserve vegetation in the district planning at natural park(Nam Han San Sung provincial natural park). The result of vegetation survey are as follows : As an actual vegetation 13 communities are recognized. Those are Quercus mongolica-Carpinus laxiflora community, Quercus mongolica-Rhododendron schlippenbachii community, Quercus serrate community, Betula platyphylla var. Japonica community, Quercus dentata community, Quercus mongolica-Pnuus densiflora community, Quercus acutissima community, Robinia pseudo-acacia community, Alnus hirsuta community, Castanea crenata community, Quercus variabilis community, Pinus densiflora community, Pinus rigida community, weed community on cultivated land(Form land), Larix leptolepis reforested land, cut over area and non-vegetation area. The grade of vegetation naturalness was divided into five degrees by characteristics of actual vegetation. I intended to make zoning plan for protection of vegetation with a special attention to the grade of vegetation naturalness and I discussed the necessity of the improvement of existing district plan. District plan was proposed as Fig. 5.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.2
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• pp.47-57
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• 2008

Physiological and biochemical changes of five species of genus Quercus exposed to ozone fumigation were investigated to assess their tolerance against ozone toxicity. At the end of 150 ppb ozone fumigation, chlorophyll contents, photosynthetic characteristics, malondialdehyde(MDA) and antioxidative enzyme activities were measured in the leaves of five Quercus species(Quercus acutissima, Q. aliena, Q. palustris, Q. serrata, and Q. variabilis). Chlorophyll and carotenoid contents, net photosynthesis and carboxylation efficiency decreased after ozone treatment, indicating that $O_3$-exposed plants underwent physiological inhibition. The reduction rate of total chlorophyll contents and carboxylation efficiency were respectively 15% and 34% for Q. aliena and 38% and 62% for Q. variabilis. The amount of MDA increased with the highest increase rate of 140% in Q. acutissima which also showed the highest increase rate(60%) of superoxide dismutase(SOD). Ascorbate peroxidase(APX) activity increased in Q. variabilis, Q. serrata and Q. acutissima by ozone treatment. Based on our results, ozone tolerance of the five Quercus species was ranked as Q. aliena>Q. palustris>Q. serrata>Q. variabilis>Q. acutissima. We concluded that chlorophyll contents, photosynthesis, MDA content and antioxidative enzymes were the important physiological markers for tolerance against ozone stress, which were closely related with one another.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.692-698
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• 2001

This study has been carried out to estimate aboveground biomass and net primary production(NPP) in an average 41-years-old Quercus variabilis stand of Gongju area, 45-years-old Quercus variabilis stand of Pohang area, and 54-years-old Quercus variabilis stand of Yangyang area. Ten sample trees were cut in each forest and soil samples were collected in July to August, 2000. Estimation for aboveground biomass and net primary production were made by the equation model $Wt=aD^b$ where Wt is oven dry weight in kg and D is DBH in cm. Total aboveground biomass was 91.31ton/ha in Gongju area, 207.6ton/ha in Pohang area, and 71.39ton/ha in Yangyang area. The aboveground biomass 207.6ton/ha in Pohang area is the highest biomass production among the amount of biomass in Quercus variabils stands reported in Korea. The proportion of each tree component to total aboveground biomass was high in order of bolewood, bolebark, branches and leaves in the three forests. Aboveground total net primary production was estimated at 7.8ton/ha in Gongju area, 11.5ton/ha in Pohang area, and 6.40ton/ha in Yangyang area. There were at least 2 times higher total aboveground biomass in Pohang area than in the Gongju and Yangyang areas because of climate difference among the study areas.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.492-503
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• 2020

This study was conducted to analyze stem decay in Quercus mongolica and Quercus variabilis in Korea. To ensure even allocation, a total of 5,005 sample trees (2,504 Q. mongolica and 2,501 Q. variabilis) were cut and collected in five regions and 27 subregions. The trees were then examined for stump decay and assigned to four classes based on the degree of scar, tissue decay and decolorization, splitting, and tree hollowing. The results show that the decay rate of Q. mongolica was 66.1%, at least twice as high as that of Q. variabilis, which was rated at 35% (χ2 = 631.15, p < 0.001). The comparison among regions indicated that the highest ratio of Q. mongolica occurs in the Central Regional Forest Service zone (76.5%), followed by the Northern zone (74.8%) and Eastern zone (65.7%). In contrast, the greatest proportion of Q. variabilis is found in the Northern Regional Forest Service zone (38.6%), followed by the Southern (32.9%) and Eastern (37.8%) zones. A statistically significant difference was seen among the five zones (p < 0.05, p < 0.001). There was also a clear tendency for the proportions for the two species to increase with a rise in the DBH. With respect to age, however, a statistically significant difference was found (p < 0.01, p < 0.05) only in Q. mongolica, whose rate increased with the increase in age. Our results show that as the DBH and age increases, the conditions of tissue decay and decolorization are manifested in Q. mongolica, whereas scars are common in Q. variabilis.

• Korean Journal of Environment and Ecology
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• v.20 no.2
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• pp.103-113
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• 2006

To investigate the forest structure and to suggest basic data for forest management in the Mookdong area of the Weolchulsan National Park, thirty plots, each size is $100m^2$, were set up and surveyed. According to analysis of classification by TWINSPAN, the community was divided by five groups of Quercus variabilis-Q. mogolica(I), Q. variabilis(II), Q. variabilis-Pinus densiflora(III), P. densiflora(IV), Q. acutissima(V). The structure of communities were investigated using importance value. From the above results, it was anticipated that Quercus spp. will be dominance species instead of Pinus densiflora.

• Korean Journal of Environment and Ecology
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• v.18 no.4
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• pp.382-391
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• 2004

This study was conducted to establish the effective and systematic counter plan of conservation by analyzing vegetation on Korean endemic plants and rare and endangered plants, Abeliophyllum distichum, habitats and to present the raw data and direction on counter plan of restoration. The dominant species of tree layers were Platycarya strobilacea(Goesan-gun Chujeom-ri I), Pinus densiflora(Goesan-gun Songdeok-ri II and Yulji-ri III), Robinia pseudo-acacia(Yeongdong-eup Maechon-ri IV), Quercus variabilis(Jincheon-gun Yongjeong-ri V) and Pinus densiflora$.$Quercus variabilis(Buan-gun Junggye-ri Ⅵ). Subtree layers were dominated by Quercus dentata(1st site), Quercus serratu(2nd site), Quercus acutissima(3rd site), Robinia pseudo-acacia(4th site), Zelkova serrata(5th site) and Quercus variabilis(6th site). And the dominant species of shrub layers were Lindera obtusiloba(1st and 5th site), Lespedeza bicolor(2nd site), Stephunandra incisa(3rd site), Quercus aliena(4th site) and Rhododendron schlippen-bachii(6th site). The dominant species of herb layers were surveyed Humulus japonicus$.$Pueraria thunbergiana(1st site), Oplismenus undulatifolius(2nd and 4th site), Carex siderosticta$.$Pueraria thunbergiana(3rd site), Streptolirion cordifolium$.$Humulus japonicus(5th site) and Sasa borealis(6th site). Among the surveyed sites, the Goesan-gun Yulji-ri supremely abounded in species and individuals, and there was surveyed each 21 species and 116 individuals. As well, this site showed the highest H'(1.123) and H'$_{max}$(1.322). Therefore, Goesan-gun Yulji-ri formed diverse vegetation and Yeongdong-eup Maechon-ri and Buan-gun Junggye-ri showed relatively poor vegetation.ation.

• Korean Journal of Environment and Ecology
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• v.19 no.2
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• pp.83-89
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• 2005

To investigate the vegetation structure of mountain ridge from Bubong to Poamsan, 16plots$(400m^2)$ set up with random sampling method were surveyed. Two groups of Quercus mongolica-Pinus densiflora community, Quercus variabilis-Pinus densiflora-Quercus mongolica community were classified by cluster analysis. Quercus mongolica was a major woody plant species in the ridge area from Bubong to Poamsan, and Quercus variabilis and Pinus densiflora were partly occupied in lower elevations. High positive correlations were proved between Lespedeza maximowixcii and Pinus koraiensis, Fraxinus sieboldiana and Rhododendron mucronulatum, Acer mono and Weigela subsessilis, and relatively high negative correlations were proved between Symplocos chinensis for. pilosa and Fraxinus sieboldiana, Rhododendron mucronulatum. Species diversity(H') of investigated groups were ranged from $0.9066\~1.0821$, and it was relatively low value compared to that of mountain ridge area of other national parks.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.170-176
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• 2008

Organic carbon distribution and carbon budget of a Quercus variabilis forest in the Youngha valley of Mt. Worak National Park were investigated. Carbon in above and below ground standing biomass, litter layer, and soil organic carbon were measured from 2005 through 2006. For the estimation of carbon budget, soil respiration was measured. The amount of carbon allocated to above- and below-ground biomass was 56.22 and 13.90 ton C ha$^{-1}$. Amount of organic carbon in annual litterfall was 2.33 ton C ha$^{-1}$ yr$^{-1}$. Amount of soil organic carbon within 50 cm soil depth was 119.14 ton C ha$^{-1}$ 50 cm-depth$^{-1}$. Total amount of organic carbon in this Q. variabilis forest was 193.96 ton C ha$^{-1}$. Of these, 61.43% of organic carbon was allocated in the soil. Net increase of organic carbon in above- and below-ground biomass in this Q. variabilis forest was estimated to 7.68 ton C ha$^{-1}$ yr$^{-1}$. The amount of carbon evolved through soil respiration was 6.21 ton C ha$^{-1}$ yr$^{-1}$. Net amount of 1.47 ton C ha$^{-1}$ yr$^{-1}$ was absorbed from the atmosphere by this Q. variabilis forest.