• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.735-749
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• 2020

Objectives: The aim of this study was to investigate airborne pollen counts, inhalant allergen sensitization rate, and allergic disease prevalence among elementary school children in Ulsan, South Korea during 2012-2018. Methods: Burkard samplers for pollen were installed on rooftops in suburban and urban areas in Ulsan. A 24-hour sampling of airborne allergens was conducted six days/week from January 1, 2013 to November 31, 2018. Skin prick tests were done with a total of 4,246 primary school students residing in urban and suburban areas in 2012, 2014, 2016, and 2018. This study examined sensitization to 20 major inhalant allergens. Results: The highest monthly counts of airborne pollen were observed in April and September each year. Among the pollen identified over the six years, pine showed the highest pollen counts (44.3%), followed by oak (22.3%), alder (6.3%) and Japanese hops (4.3%). Tree pollen predominated from March to June, and weed pollen predominated from August to October. Higher sensitization rates for inhalant allergens were observed in Dermatophagoides farinae (42.4%), Dermatophagoides pteronyssinus (43.6%), cat fur (12.1%), birch (9.9%), oak (9.6%), and alder (8.7%). The inhalant allergen sensitization rate was highest in the group with comorbidity (asthma and/or rhinitis and atopic dermatitis), and respiratory allergic disease (asthma and/or rhinitis) was higher than that of atopic dermatitis. Conclusion: Both the counts of tree pollen in the air and the sensitization rate for tree pollen were high in Ulsan. The temporal change in respiratory allergic diseases was similar to that for the sensitization rate of tree pollen, such as oak. In the future, it is considered that additional continuous research on various inhalant allergens and pollen should be conducted.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.753-760
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• 2021

This study was carried out to discover suitable packaging methods during the cold or frozen storage of sawtooth oak and Japanese larch seedlings, which are major afforestation tree species in Korea. The weight loss rate of sawtooth oak was lower under frozen storage at -2℃ (maximum, 33.7%) than under cold storage at 2℃ (maximum, 61.0%). A film liner treatment inside the packaging box effectively suppressed the increase in the weight loss rate. For the sawtooth oak containerized seedlings, when stored at -2℃, the rate of weight loss was 17.9 to 25.4% in the untreated group and less than 1% in the film liner treatment group. Similar results were observed with Japanese larch. After two months of freezing at -2℃, both species maintained a low index of 1.0 - 1.1 with regard to the degree of shoot desiccation of containerized seedlings, and there was no significant difference between the treatments. On the other hand, the chlorine dioxide treatment could more effectively reduce the occurrence of mold and shoot desiccation than a PE single treatment in bare-root seedlings. According to these results, it was concluded that frozen storage is generally suitable as a means of long-term storage compared to cold storage of sawtooth oak and Japanese larch. A chlorine dioxide treatment at 20 ppm was effective for maintaining seedling quality levels during storage, demonstrating the good effect of suppressing the occurrence of shoot desiccation and the occurrence of mold.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.153-160
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• 2023

In this study, biochar was produced from biomass waste, and its methylene blue adsorption capacity was evaluated. The major components of the biomass were cellulose, hemicellulose, and lignin. Ash content was high in waste wood. Carbonization yield decreased as carbonization temperature increased, as did hydrogen and oxygen content, but carbon content increased. Increased carbonization temperature also increased the specific surface area and micropores of biochar. At 600 ℃, biochar had the highest specific surface area (216.15~301.80 m² /g). As a result of methylene blue adsorption on biochar carbonized at 600 ℃, oak, waste wood, and pruned apple tree branches fit the Freundlich model, while pruned peach tree branches fit the Langmuir model. In the adsorption kinetics of methylene blue on biochar, oak and pruned peach tree branches fit a pseudo-first-order model, while waste wood and pruned apple tree branches fit a pseudo-second-order model.

• The Korean Journal of Ecology
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• v.10 no.4
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• pp.183-193
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• 1987

An investigation was performed to draw the decy map of litters on the floors of pine and oak forests in Korea and to reveal the turnover cycles of N, P, K, Ca and Mg in litters. Isodecay constant lines of litter organic matter, which are depended upon the altitude, latitude and orientation, were drawn on the Korean map. The decay constants of organic matter of litters were higher in the broadleaf tree forests than in the needleleaf tree forests, and in the grasslands than in the forests. The amount of mineral nutrients such as N, P, K, Ca and Mg returned annually to soils is higher in the broadleaf tree forests than in the needle leaf tree forests, and highest in the Quercus mongolica forest of the forests.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.2
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• pp.39-43
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• 2009

we studied and analyzed a tree mortality of 7 species(Pinus koraiensis etc) in surface forest fire area. In this results, the order of tree mortality was Cryptomeria japonica>Pinus koraiensis>Pinus densiflora>Pinus thunbergii>Larix leptolepis>Pinus rigida>Quercus. More damaged crown was higher tree mortality and more d.b.h was less tree mortality. Especially, oak trees in which a damage rate of crown was less 30% almost survived.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.382-393
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• 2012

The purpose of this study was to research the vegetation structure of the Bongamsa Forest Genetic Resourses Resreve Area in Mt. Heuyang, Mungyeong, Gyeongsangbuk-do. For doing this, ninety-two plots($100m^2/plot$) were set up and investigated, and then Classification analysis and Ordination analysis were carried out. As a result, the vegetation of this area is divided to nine communities; Quercus mongolica community, Quercus variabilis community, Pinus densiflora community, Pinus densiflora-Quercus serrata community, Pinus densiflora-Quercus mongolica community, Quercus serrata community, Decideous broad leaf community, Pinus koraiensis community, Larix kaempferi community. To compare between the communities, statistical analyses were conducted with topographical condition and the results of the vegetational investigation of each community. In altitude, slope, the number of species, the number of individuals in canopy and the number of individuals of understory layer, the mean averages among the communities were different in statistically significance. Then we analysed the vegetation community structure with Importance Percentage of each stratum. The oak tree communities were expected to keep or expand the actual communities because oak trees are spread widely in canopy and understory layers. But the pine tree dominant communities were expected to be succeeded to oak tree communities in the future because of the wide expansion of oak trees.

• Journal of architectural history
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• v.16 no.1
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• pp.9-28
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• 2007

We investigated the changes in the species of the woods used for Korean ancient and historic architectures, which include prehistoric excavated relics and existing wooden buildings in South Korea. The species data were collected from various sources such as excavation and repair reports, journal papers, and a few unpublished documents. We divided the building Periods as Paleolithic, Neolitic, Bronze Ages, Iron Age/Three Kingdoms, Koryo, Joseon (early, middle, late) and modem periods. In prehistoric periods, hardwoods were major species. Oak (Quercus spp.) woods dominated (94 percent in average); the others (5%) were Juglans mandshurica, Platycarya strobilacea, Castanea crenata, and few softwoods(1%). During Iron Age and Three Kingdom periods, oaks remained as a major species (57%) and others Platycarya strobilacea(21%), Castanea crenata(13%), and Pinus spp. (6%). The oak woods decreased in Koryo period and they occupied only 1.1%. Instead of oaks, pine (Pinus spp., 71%) and Zelkova serrata (22%) dominated in Koryo. In early and middle Joseon periods, pine woods (73%) remain as a major species and the others were oaks (14%) and Zelkova serrata (9%). As late Joseon came, the pine woods occupied more than 88%. In the late 19th and early 20th centuries, a few boreal species such as larch (Larix spp.) and spruce (Picea spp.), which grow in cold area, were found. We believe they were transported from northern Korea. The existing buildings in Korea are mainly from Joseon period and a few from late Koryo periods. During these periods, pine woods were used for most buildings. For such reason, pine woods were known as 'representative materials for historic buildings'. but earlier times, broad-leaved trees, i.e., oak and Zelkova woods were major materials. The changes in building materials resulted from both climate and human impacts. The dry climate and disturbed forests induce more pines in the mountains. We also compared the wood qualities of the species and found that Zelkova woods were superior ones and deserved more planting for future demands in the repair for historic buildings.

• Mycobiology
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• v.43 no.4
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• pp.458-466
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• 2015

Oak tree death caused by symbiosis of an ambrosia beetle, Platypus koryoensis, and an ophiostomatoid filamentous fungus, Raffaelea quercus-mongolicae, has been a nationwide problem in Korea since 2004. In this study, we surveyed the yeast species associated with P. koryoensis to better understand the diversity of fungal associates of the beetle pest. In 2009, a total of 195 yeast isolates were sampled from larvae and adult beetles (female and male) of P. koryoensis in Cheonan, Goyang, and Paju; 8 species were identified by based on their morphological, biochemical and molecular analyses. Meyerozyma guilliermondii and Candida kashinagacola were found to be the two dominant species. Among the 8 species, Candida homilentoma was a newly recorded yeast species in Korea, and thus, its mycological characteristics were described. The P. koryoensis symbiont R. quercusmongolicae did not show extracelluar CM-cellulase, xylanase and avicelase activity that are responsible for degradation of wood structure; however, C. kashinagacola and M. guilliermondii did show the three extracellular enzymatic activities. Extracelluar CM-cellulase activity was also found in Ambrosiozyma sp., C. homilentoma, C. kashinagacola, and Candida sp. Extracelluar pectinase activity was detected in Ambrosiozyma sp., C. homilentoma, Candida sp., and M. guilliermondii. All the 8 yeast species displayed compatible relationships with R. quercus-mongolicae when they were co-cultivated on yeast extract-malt extract plates. Overall, our results demonstrated that P. koryoensis carries the yeast species as a symbiotic fungal associate. This is first report of yeast diversity associated with P. koryoensis.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.113-123
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• 2001

The main purpose of this study was to provide information on attenuation effects in forest tree belt of pine stand and oak stand. The relationships between DBH, tree height, clear length, crown area and number of trees and also between distance from noise origin, landslope etc. were analysed by correlation and multiple regression. The results obtained were as follows : 1. There was no difference between pine stand and oak stand in effecting noise attenuation. 2. The noise pressure was highly correlated with all of seven elements tested and both DBH and distance from noise origin have higher r-values than the others. For the pine stand, it was 0.9133 in DBH and 0.9630 in the distance and for the oak stand, 0.9296 in DBH and 0.9565 in the distance. 3. The optimum regression equation for pine stand and oak stand were made by combination of two variables (DBH and distance). The table of noise attenuation was made by optimum regression equation. In the case of pine stand, the attenuation ratio was 29% at 5m, 31.6~32.6% at 10m, 38.3~39.8% at 20m and 45.2~46.6% at 30m. And case of oak stand, the attenuation ratio was 29% at 5m, 31.6~34.2% at 10m, 38.6~41.4% at 20m and 45~47.2% at 30m. 4. As the noise pressure limit at the Urban housing area according to environmental laws is under 55dB, it is suggested by the table of noise attenuation that the distance, and DBH for the pine and oak stand are over 20m, 400cm and 30-35 trees, respectively.

• Research in Plant Disease
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• v.20 no.4
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• pp.295-298
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• 2014

Oak wilt caused by Raffaelea quercus-mongolicae was first noticed in South Korea in 2004 and, ever since, its distribution and damage have been increasing. To screen a fungicide effective for oak wilt control by tree injection, laboratory and field experiments were conducted. Ten fungicides and one antibiotic were examined in vivo for their effectiveness in restricting the growth of R. quercus-mongolicae and R. quercivora (Japanese oak wilt pathogen) isolates. To the Korean isolates of R. quercus-mongolicae, chlorothalonil showed the highest fungicidal effects, followed by benomyl and propiconazole. To the Japanese one, propiconazole was highest in the fungicidal effectiveness, followed by benomyl and bitertanol. Propiconazole was selected for field-testing of its control efficacy because it showed good fungicidal effects in vitro and systemic activity. The control efficacy in the field was 87.5% in the first year of injection and 66.7% in the second year, indicating the fungicidal effects last at least over one year.