• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.49-54
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• 2017

We collected and reared Theragra chalcogramma walleye pollock brood-stock for use in natural spawning tests and undertook to obtain domestic pollock via fertilized egg capture, development of fertilized eggs, and absorption of yolk sac after hatching. Whole pollock were caught with trammel and set nets and immediately placed in a deep-sea water tank. Adults were the most common pollock age group (43.0%; n = 86) among the 254 pollock captured in March 2014 with 57.9% (n = 147) being captured off Southern Gosung, Korea. The main spawning period of pollock is February (spawning phase of 91% of pollock). From the deep-sea tank, we collected 1640 mL of naturally fertilized eggs (~820,000 eggs) from 12 spawning events occurring between February 4 and 22 2015. The floating/ live eggs were maintained in deep-sea water tanks at $5.5{\pm}0.2^{\circ}C$. Egg size was $1.5{\pm}0.03mm$. Six hours after fertilization the eggs were at the 2 cell stage, and the eggs hatched approximately 340 hours after collection. At hatching, larval length and yolk sac area were $5.2{\pm}0.25mm$ and $9.5{\pm}1.00mm^2$ (100%), respectively. Four days after hatching, the yolk sac area was $2.2{\pm}0.53mm^2$ ($23.1{\pm}5.55%$). This is the first report of collection of naturally fertilized eggs from pollock and their subsequent hatching while held in an indoor deep-sea water tank. The results suggest that such collection could assist in the recovery of pollock resources and the possibility of domestic rearing of cultivated larvae.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.295-306
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• 2018

In the present study, we compared the effects of 50% ethanolic extracts of Chinese and Korean Wolfiporia cocos (CPE and KPE) on in vitro lipid accumulation in 3T3-L1 cells and their anticancer activities in Sarcoma 180 cells. We further compared the anticancer activities and the 50% inhibitory concentrations ($IC_{50}$) of CPE with KPE with cultivated for one and two years in a landfill and a facility (LPE and FPE), respectively. In addition, the single oral dose toxicities of CPE and KPE were evaluated in mice. Lipid accumulation was inhibited after 48 hours, in CPE and KPE treated 3T3-L1 cells; however, no significant difference was observed between CPE and KPE in their lipid accumulation inhibitory activities. The anticancer activity of KPE was higher than that of CPE at $300{\mu}g/mL$ (p<0.05), revealing the possibility of an auxiliary biological means for origin identification. The anticancer activities of LPE and FPE were significantly stronger than that of CPE (p<0.05) but there was no difference between extracts from one- and two-year-old W. cocos, irrespective of the cultivation method. In single oral dose toxicity tests, CPE and KPE did not induce mortality during the 14-day observation. Thus, the 50% of lethal dose ($LD_{50}$) of CPE and KPE were estimated to be higher than 2,000 mg/kg. Taken together, our results indicate that the anticancer assay could be an auxiliary means of identifying the origin of W. cocos. In addition, artificial cultivation could be an alternative way to reduce the import of W. cocos. Lastly, 50% ethanolic W. cocos extracts could be potential candidates for obesity and cancer managements.

• Korean Journal of Plant Resources
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• v.29 no.2
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• pp.241-263
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• 2016

This study was carried out to survey the vascular plants on Mt. Seokbyeongsan (1,055 m) and provide a basis for the conservation and management of plant resources. The vascular plants were surveyed from March to October 2015. The flora on Mt. Seokbyeongsan was classified as follows: 102 families, 295 genera, 454 species, 4 subspecies, 51 varieties, 7 forms, and a total of 516 taxa. Endemic plants included 17 families, 24 genera, 25 species, 1 variety, and a total of 26 taxa. The Korea Forest Service assignment of rare plants, including 21 families, 33 genera, 33 species, 3 varieties, and a total of 36 taxa, was investigated. Moreover, the Ministry of Environment assignment of rare plants, including 13 families, 17 genera, 17 species, 1 variety, and a total of 18 taxa, was investigated. Floristic special plants in the surveyed area were divided into five classes (Classes I-V): 42 taxa of Class I, 26 taxa of Class II, 35 taxa of Class III, 20 taxa of Class IV, and 9 taxa of Class V for a total of 132 taxa. Naturalized plants were 18 taxa, and plants threatened by climate change were 48 taxa.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.250-258
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• 2014

The purpose of this study was to promote effective health management of orthodontics patients by determining the effect that the factors related to orthodontics would have on the Oral Health Impact Profile (OHIP), and the subjects of this study was the local residents of Gangwon-do Province. The mean score of OHIP for the subjects was 2.97, while the mean score of physical factor was 3.01. The mean score of psychological factor was found to be 2.93. Thus, the orthodontics was found to have more influence on psychological factor. The item that had the greatest influence among the 10 items of Oral Health Impact Profile was found to be the question, "Have you ever felt shy due to your dental shape?" which had the mean score of 2.66. The characteristics that had significant effect on OHIP among general characteristics were found to be the age, religion, occupation, income, smoking or non-smoking status(p<0.05). In terms of the age, the age of 20 or less had the greatest effect with the mean score of 2.53. In relation to the occupation, the production/sales occupation had an influence with the mean score of 2.56 (p<0.05). Those with income exceeding KRW 4 million were found to have the mean score of 2.83 and 2.78. It turned out that the smokers had greater effect compared to the non-smokers in relation to the smoking/non-smoking status as the income was higher (p<0.05). The characteristics of orthodontics were manifested as the health perception in relation to Oral Health Impact Profile (OHIP) (p<0.05). Regarding the reason why they underwent the orthodontics, the 'uncomfortable feeling in chewing' was found to have the mean score of 2.69 and 2.67 (p<0.05). Regarding the orthodontics period, 1 to 2 years were found to have the mean score of 2.80 and 2.74, thus having an influence (p<0.05). In relation to the regret/non-regret over orthodontics, those who indicated that they regretted were found to have the mean score of 2.65 and 2.60 (p<0.05). Analysis of the relationship between Characteristics of orthodontic treatment and OHIP, orthodontic treatment reasons, oral health awareness, whether orthodontic treatment regret showed a statistically significant correlation. it is considered necessary to make constant efforts to help orthodontics patients, both physically and psychologically, in the course of treatment and improve their quality of lives.

• Korean Journal of Environment and Ecology
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• v.34 no.4
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• pp.318-333
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• 2020

The Nakdong-Jeongmaek extends north and south from Taebaek-si of Gangwon-do to Busan metropolitan city and includes a wide range of forest zone from temperate to the warm-temperature forest. The purpose of this study was to analyze the vegetation structural characteristics of the Quercus mongolica-dominant community, which was distributed in the largest area in Baekdudaegan and Jeongmaek, by region and communities in the Nakdong-Jeongmaek. For the study, a representative 6 sites were selected: Baekbyeongsan, Chilbosan, Baegamsan, Unjusan, Goheonsan, and Gudeoksan. The survey of the 6 sites showed that the canopy had over 85% the importance percentage of Quercus mongolica. In the understory, Rhododendron schlippenbachii, Fraxinus sieboldiana, etc. were located and Fraxinus sieboldiana, Lespedeza maximowiczii, Tripterygium regelii and so on were found in the shrub. The importance percentage of 4 communities of Quercus mongolica, which were separated by TWINSPAN, in the canopy was more than 80%, and the dominant species in the understory and shrub were the same. Currently, Quercus mongolica has been identified as the understory following the canopy, and the Quercus mongolica-dominant community is expected to continue unless there are external factors. In the temperate forest regions in Korea, Quercus spp.and Carpinus laxiflora form the major forest physiognomy in the natural forest state. Based on these characteristics, the Quercus mongolica-dominant community on the ridge of the Nakdong-Jeongmaek is considered to have characteristics of temperate forests in Korea. The Quercus mongolica community is a representative cool-temperate deciduous forest and known as a climatic climax in the upper section of the mountains in the Korean Peninsula. Trees of the same species should be distributed at each layer to maintain the dominant species' status in the canopy's climax forest. Therefore, the Quercus mongolica community is considered the climax forest in the ridge of the Nakdong-Jeongmaek.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.237-245
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• 2006

Changes of the biomass, net primary productivity and P/B ratio during abandoned field succession after shifting cultivation were investigated in Pyoungchang, Gangwon-Do, Korea. Aboveground standing biomass of herb species showed the maximum value (3.8 ton/ha) in the 5 year old-field, and decreased thereafter. Litter dry weight was depicted as a parabola form showing the gradual increment during the first 50 years and slight decrease thereafter. Basal area tended to increase logarithmically during abandoned field succession. Tree density showed the gradual increment during the first 15 years and decreased thereafter by the self-thinning process. In the later successional stage (80 years old-field), the shoot density distribution of the tree species by DBH class showed the reverse J shaped curve and Quercus mongolica dominated. Total standing biomass increased slowly in the earlier successional stages and later successional stages, and increased rapidly during the mid-successional stages ($10{\sim}50$ years old-field). Total standing biomass in the 5, 10, 20, 50 and 80 years old-fields were estimated 5, 14, 75, 251 and 373 ton/ha, respectively. Annual net primary productivity were depicted as a parabola form showing the gradual increment during the first 35 years and declined thereafter. The increment rates of the annual net primary productivity in the earlier successional stages showed the higher value than mid-successional stages. The annual net primary productivities in the 5, 10, 20, 35, 50 and 80 years old-field were estimated 8.6, 9.3, 12.9, 15.1, 13.7 and 3.6 ton/ha/yr, respectively. The estimated P/B ratio tended to decrease exponentially during abandoned field succession. The estimated P/B ratio in the 5, 10, 20, 50 and 80 years old-field were 0.60, 0.39, 0.19, 0.06 and 0.01, respectively. These results were fairly in accordance with the bioenergetics model during the forest succession projected by Odum(1969).

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.215-224
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• 2013

We clarified the background for establishment of vegetation by comparing the spatial distribution maps of vegetation and substrate on a gravel bar in the Bangtae stream located on Inje-gun of Gangwon-do, the central eastern Korea. The total vegetation coverage was higher in the interior and lower in the marginal parts of the gravel bar. Spatial distribution of vegetation on the longitudinal section of the gravel bar tended to be arranged in the order of shrub, subtree, and tree dominated vegetation types from the front (upstream) toward the rear (downstream) parts. Coverage of the herbaceous plants was higher in the central and rear parts and lower in the front and right parts of the gravel bar. Vegetation height was higher in the rear part and became lowered as move toward the front part. Substrate was distributed in the order of boulder, gravel, sand, and boulder from the front toward the rear parts. Ordination of stands based on vegetation data was arranged in the order of annual plant, perennial herb, shrub, and tree dominated vegetation as move from the right to the left parts on the axis I. Species richness was higher in the order of Pinus densiflora community, Phragmites japonica community, Salix gracilistyla community, Fraxinus rhynchophylla community, annual plant dominated vegetation, and Prunus padus for. padus community based on the species rank-abundance curve. The order based on the Shannon's index was some different; diversity of Phragmites japonica community and Salix gracilistyla community, which showed higher dominance degree, were low differently from species richness. In conclusion, it was evaluated that the gravel bar newly established toward the upstream and vegetation dynamics of the gravel bar seemed to follow ecosystem mechanisms of succession. As were shown in the above results, the Bangtae stream corresponded to the upstream and thereby particle size of substrate was big. Therefore, they move by rolling and are accumulated for the upstream. Vegetation types were arranged in the order of woodland, shrub-land and grassland from the rear toward the front parts of the gravel bar and thereby reflected the formation process of the bar. However, the gravel bar is disturbed frequently by not only the running water but also the suspended sand as the dynamic space. Such disturbances cause habitat diversity and consequently led to high biodiversity.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.129-137
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• 2008

Alien apple snails (Pomacea canaliculata, Pomacea insularus) used in environmentally-friendly agriculture are different from indigenous snails found in Korea. Due to high herbicidal effects and cost-effectiveness, the number of farmers using the snails has been growing every year since 2000. Moreover, in 2008, because of the outbreaks of avian influenza throughout the country from March to May, 2008, central and local governments recommended the use of alien apple snails in agriculture as an alternative to the ducks-oriented environmentally-friendly agriculture. Therefore, it is expected that the use of alien apple snails in agriculture should be expanded in a near future. Since alien apple snails lay eggs with 95.8% of eclosion rate, they are considered to be potential pests unlike indigenous snails. In addition, Japan, Taiwan and most of the southeast Asian countries had already experienced severe ecological and agricultural damage by the alien apple snails. Subsequently, International Union for Conservation of Nature and Natural Resources (IUCN) designated P. canaliculata as one of "the 100 of the world's worst invasive alien species". It seems highly likely that the alien apple snails in Korea pose a potential threat to conservation of ecosystem and biodiversity since the snails were either found or invaded into the natural environments in some regions of Gangwon-Do and southern parts of Korean Peninsula. However, just recently, agricultural authorities and farmers using alien apple snails in agriculture opposed a proposition of designating the alien apple snails as an ecosystem-disturbing animal described by the Wildlife Protection Act. This is because there has been no concrete evidence of the ecological risk imposed by the alien snails up to now in Korea. Subsequently, in this paper, we analysed the ecological and agricultural risks imposed by the alien snails from the studies done in domestic and abroad. In addition, we proposed an urgent need and reasoning for ecological risk management of the alien snails at the national level as well as using the snails in agriculture.

• Journal of the Korean Wood Science and Technology
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• v.40 no.6
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• pp.378-388
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• 2012

This study was carried out to investigate the optimum condition for sap exudation of Juglans mandshurica in comparison with Acer mono Max. trees in a site of Inje-Gun, Gangwon-Do, Korea. Amount of sap exudation, air temperature, relative air humidity and tree diameter at breast height (DBH) were monitored for the period of February 1 through March 31, 2008, and correlation analysis of several factors affecting on sap exudation was carried out. Sap exudation from J. mandshurica initiated on Feb. 28 as the same time in case of A. mono and continued for a month, and enhanced in early March compared to around the middle of March for A. mono. The amount of sap of A. mono was linearly proportional to the diameter at breast height (DBH) but there was no apparent relationship for J. mandshurica. As the amount of sap exudation per tree increased then sap exudation per unit DBH was also linearly proportional in both J. mandshurica and A. mono. The amount of sap exudation per unit DBH of J. manshurica were $0.3{\pm}0.1{\ell}/cm$ on average, which was one third times of $0.9{\pm}0.1{\ell}/cm$ for A. mono. During the days of enhanced sap exudation, the atmospheric conditions such as air temperature and relative humidity around J. manshurica trees were very similar with those of A. mono. The minimum temperature was a significant factor affecting the amount of sap of J. mandshurica whereas the range of temperature was the principal factor for A. mono. In conclusion, the sap of J. mandshurica exudated in atmospheric conditions similar to A. mono, but the amount of sap was affected by different atmospheric factors compared to A. mono.

• Journal of Environmental Policy
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• v.11 no.3
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• pp.25-47
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• 2012

This research is to suggest an ecological management methods by classification of biotope type and its mapping for Tricholoma matsutake. The target area was construction site of the East Hongchun - Yangyang Highway (Yangyang section) where massive production of Tricholoma matsutakes is in place. Specifically, the 700 m long range of area around the road route, Yangyang section, which is over a total area of $19,79km^2$. The flow of this research was as follows: first studied were the characteristics of the Yangyang Tricholoma matsutakes; second, reviews on previous studies on Tricholoma matsutakes; third, the formulation of standards and processes of biotope type considering Tricholoma matsutake production; and fourth, mapping of biotope considering the production area of Tricholoma matsutake. In 24.77% of the region, slope angle measured $30{\sim}40^{\circ}C$, which is suitable for Tricholoma matsutake production. Also, 17.44% of the region had southward vegetation structures, and as for the Pinus densiflora; 26.00% had average receipts; the tree ages was $38{\pm}8.34$ years; and the average density of canopy layer was $9.55{\pm}4.89/100m^2$. The soil acidity (pH) values of 5.0 to 5.6(47.96%) > 5.6 to 7.0(42.90%) > 4.0 to 5.0(9.14%) were slightly high for Tricholoma matsutake growth; but 57.10% of the area had a soil pH of 4.0-5.6. The organic horizon (A0 layer) was $3.39{\pm}2.14cm$, and the mean depths were 4-6cm(78.03%) > 0-2cm(18.10%) > 2-4cm(3.87%). Based on the results of previous studies and field researches on the presence of vegetation (the pine dominance ratio), the topographic structure (the terrain characteristics and slopes), the receipt, the soil structure (the soil acidity and the organic layers interposed between the depths), and the vegetation density, six clusters based on the identified types of biotopes are produced in this paper. Area of distribution according to the type of biotope was Tricholoma matsutake of the potential-production (II) biotope (32.86%) > Tricholoma matsutake of the inadequate-production biotope (22.17%) > Tricholoma matsutake of the adequate (II)-production biotope (17.79%) > Tricholoma matsutake of the adequate (I)-production biotope (14.86%) > Tricholoma matsutake of the potential-production (I) biotope (9.77%) > Tricholoma matsutake of the produced biotope (2.55%).