• Korean journal of applied entomology
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• v.51 no.3
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• pp.285-293
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• 2012

Occurrence Hyphantria cunea was confirmed in 35 cities and counties nationwide in 2011, each of which reported some form of crop and/or ecological damage caused by the moth. Only a larva of the black-headed form were reported to have occurred in the nation. H. cunea was found in street trees 66.7%, followed by landscape trees 19.4% and forests 13.9%. This suggests that artificial environment 86.1% suffered from H. cunea more severely than natural forests. The study identified 44 families and 102 species of host plants, and found an additional 29 species, to those which had been identified in previous studies. At present, the identified host plants of H. cunea are composed of 62 families and 219 species in total since their first appearance was reported approximately 50 years ago. Host plants include 5 species of food crops (2.3%), 6 species of vegetables (2.7%), 4 species of medicinal crops (1.8%), 1 species of industrial crops (0.5%), 13 species of fruit trees (5.9%), 6 species of other trees crops (2.7%) as well as a further 5 species of farmed crops (2.3%). Seven species of host plants (18.4%) originate from North America where Hyphantria cunea has been introduced from, while 11 species (29.0%) are from China and Japan, Europe and India were the native sources of (10.5%) of the origin with 4 species, respectively. Seventeen species of trees, including Platanus occidentalis L., Ulmus davidiana (var.) japonica (Rehder) (Nakai) and Cornus officinalis (Siebold & Zucc) were heavily noted to be heavily infected with larval populations.

• The Korean Journal of Pesticide Science
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• v.8 no.3
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• pp.220-230
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• 2004

This study was conducted of Korean native plants to screen herbicidal activity which could be used for the development of new natural herbicides. Ninety-eight plants were collected from Wan Island, Chollanamdo in Korea and their methanol extracts were obtained. Herbicidal activities of the methanol extracts were determined by seed bioassay using canola (Brassica napus L.) seedlings. Among ninety-eight species, twenty plants were highly herbicidal ($GR_{50}<1,000\;{\mu}g\;g^{-1}$): Abies holophylla MAXIM., Ailanthus altissima (MILL.) SWINGLE, Anthemis nobilis L., Aralia elata SEEM., Artemisia iwayomogi KITAMURA, Asarum sieboldii MIQ., Brassica campestris subsp. napus var. nippo-oleifera MAKINO, Clematis terniflora DC., Crataegus scabrida SARG., Gnaphalium affine D. DON, Jasminum nudiflorum LINDL., Kalopanax pictus (THUNE.) NAKAI, Machilus japonica S. et Z., Myrica rubra S. et Z., Osmunda japonica THUNB., Phytolacca esculenta V. Houtte, Platanus occidentalis L., Quisqualis indica L., Rubus hirsutus THUNB., Yucca smalliana FERN. Fifty plants were shown moderate herbicidal activity $(1,000\;{\mu}g\;g^{-1}, however, twenty-eight plants were not shown any herbicidal activity.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.4
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• pp.7-20
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• 2004

This study was executed to find out how to improve the planting and use of landscaping plants in Chuncheon. The number of street trees was 17,877 in 2003. The major species of street trees were Ginkgo biloba(52.7％), Prunus sargentii(15.3％), Zelkova serrata(8.9％), Platanus occidentalis(7.3％). Salix babylonica and Platanus occidentalis were decreased, while Prunus sargentii and Zelkova serrata were increased. Salix babylonica is a good species for a lakeside city, but its seeds cause allergies to some people. Most of the trees have been removed in Chuncheon. The planting of Salix babylonica(♂) resulted in no problems, and it should be propagated to plant. The soil of several areas was analysed to investigate soil conditions. The outskirts of city had good conditions in pH, organic matter and minerals, but the downtown areas had high alkalic, due to alkali from footpath concrete blocks. Appropriate pruning adds to the aesthetic and prolongs the useful life; it also requires less managing of insects and diseases to maintain good healthy of street trees. Street trees were not properly pruned due to electric lines and shortage of pruning information. The pruning was controlled by Korea Electric Power Co, which has no pruning information. Pruning must be maintained by a professional landscape company to maintain good shape such as with Bonsai. The Shrubs planting zone between street trees and other trees, and preservation plates were established for healthy of street trees. They have to be repaired and maintained well to keep better environmental conditions. The number of tree and flower species of 68 schools in Chuncheon were 12 and 16, respectively. The species that showed high preference were Juniperus chinensis, Pinus koraiensis, Pinus densiflora, Rosa centifolia, Forsythia koreana, and Rhododendron schlippenbachii. The high frequency of the protection trees designated by Chuncheon were Pinus densiflora, Ginko biloba, Zelkova serrata, Quercus species. It was thought that the diversification of street tree species, the selection of street trees suitable to each space, the generalization of use of native species, the appropriate pruning and proper fertilization, the control of pests and diseases, and the opinions of citizens concerning landscape plants were needed to improve the planting, use and maintenance of landscaping plants in Chuncheon.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.95-104
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• 2016

The objective of this paper is to develop volume equation of street tree and its carbon stock for urban forest in Seoul. To develop the volume equation by major species in Seoul, data for street trees were obtained from four-species (e.g. Gingko biloba, Platanus occidentalis, Zelkova serrata, and Metasequoia glyptostroboides), which accounted for 79% all street trees in Seoul. This study used a variable based on diameter on breast height and four equation for calculating volume. The coefficient of determination, bias, and root mean square error were used to evaluate the precision of four equations. From these methods, the most suitable equations for Platanus occidentalis was aDb, the other was aD+bD2; coefficient of determination upper on 0.873. From the volume equation developed in this research, the estimated carbon stock were derived as about 33,760tC for four-species of urban forest in Seoul. The results of this paper offered volume equation and carbon stock that present growth information for street trees in urban forestry and these can be made available for evaluating the management for carbon in settlement.

• Korean Journal of Environmental Agriculture
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• v.15 no.4
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• pp.479-487
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• 1996

This study was conducted to investigate the phytoprotective effects of uniconazole on $SO_2$ injury in P. occidentalis. The detoxification role of free radical scavengers such as superoxide dismutase (SOD) and peroxidase (POD) was also examined under the conditions of combined treatment with uniconazole and diethyldithiocarbamate (DDTC). Uniconazole drenching significantly reduced the occurrence of visible injuries. Though shoot length, leaf area, and T/R rate were greatly decreased by uniconazole application, the tolerance to $SO_2$ was enhanced through increased chlorophyll content and activities of SOD and POD. Spray of DDTC decreased the activity of SOD and POD resulting in the increase of visible injury. Plant tolerance to $SO_2$ induced by uniconazole application was reduced by the additional application of DDTC. These results indicate that plant tolerance to $SO_2$ induced by uniconazole is associated with the reduction of vegetative growth as well as the increase in free radical scavengers such as SOD and POD.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.14-18
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• 1997

The objective of this research was to increase phytoprotective effects by combined treatment of uniconazole and free radical scavengers such as ascorbic acid or sodium benzoate on $SO_2$ injury in P. occidentalis. The plant injury, chlorophyll content and enzyme activity of superoxide dismutase(SOD) and peroxidase(POD) affected by combined treatment were also investigated. The phytoprotective role of uniconazole was nullified by spray of Diethyldithiocarbamate(DDTC) resulting in the decrease of SOD and POD activities. Free radical scavengers, sodium benzoate and ascorbic acid, did not affect SOD and POD activity, but significantly inhibited the development of visible injury, degradation of chlorophyll, and SOD and POD activity in leaves exposed to $SO_2$. The spray of ascorbic acid decreased plant susceptibility to $SO_2$ induced by DDTC application. These results indicate that uniconazole application increase SOD activity that play a role of antioxidant in plant body, but sodium benzoate and ascorbic acid do not affect enzyme activities of SOD or POD.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.23-28
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• 1999

This study measured transpiration rate of urban trees and albedos of urban surfaces, and examined the function of microclimate amelioration by urban greenspace. Transpiration rates of trees were highest in July and August of growing months. Transpiration per unit leaf area for the two months was 300-350 g/$m^2$/h for Platanus occidentalis, 210-270 g/$m^2$/h for Ginkgo biloba and Zelkova serrata, and 130-140 g/$m^2$/h for Acer palmatum. Surface albedos were 0.09 for asphalt paving and 0.68 for white wall, which reveals that light-colored surfaces are better than dark-colored ones to lower the heat build-up. Due to lack of evapotranspiration, concrete surfaces were, at t midafternoon maximum, 8$^{\circ}C$ hotter than grass ones, though the albedo of concrete paving was higher thant that of grass and trees. Summer air temperatures at places with 12% and 22% cover of woody plants were, respectively, 0.6$^{\circ}C$ and 1.4$^{\circ}C$ cooler than a place with no vegetation. To mitigate the impacts of urban heat islands, required are minimization of hard surfaces, light-coloring for building surfaces, and greenspace enlargement including more plantings.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.405-420
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• 2014

To investigate geochemical characteristics of soil and atmospheric environments by anthropogenic source, we have analyzed and determined heavy metal concentrations of the surface soils beneath roadside trees and leaves of Platanus occidentalis from 52 points in Seoul during autumn 2001. For comparison of the contents of heavy metal for the soil and leaf, we have analyzed heavy metal contents of the surface soils beneath roadside trees and leaves from 2 points in rural area of Yesan during the same time period. The composition of heavy metals of soils are relatively high for Cd, Co, Cr and Ni in industrial area (IA, Industrial Area) and high for Cu, Pb and Zn in heavy traffic area (HTA, Heavy Traffic Area). The heavy metal contents of rural area in Seoul are higher than those in Yesan. The differences of chemical compositions between the washed and unwashed leaves are high for Cd, Cu, Pb and Zn in the HTA. The element couples of Cd-Co, Cr-Ni and Pb-Zn for the soils had shown a good correlation and their contamination sources could be similar. The relationship for Pb-Cu and Cu-Zn showed good correlation in Platanus leaves. The relationship between soils and unwashed leaves show a good correlation for Cr, Cu, Pb and Zn but low correlation for Cd, Co, Fe, Mn and Ni. It is thought that the Cr, Cu, Pb and Zn were derived from contaminants of soils, whereas Cd, Co, Fe, Mn and Ni were originated from atmospheric source. From the spatial variations of elements for soils and leaves, Ni and Cr were dominant in the soils of IA and Cd, Cu and Zn were dominant in those of HTA. The Contamination by Cd-Pb and Cu-Zn in unwashed leaves were analyzed to show similar patterns. Using the enrichment factors (EF) of heavy metals in unwashed leaves, the EF sequences were to be Cu, Zn, Pb, Mn, Co, Ni, Cd and Cr. We identified that Cu, Zn, Pb and Mn were most problematic of environmental hazard in Seoul.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.164-176
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• 1992

This study was conducted to determine the toxic effects of air pollutants on landscaping trees, Pinus densiflora, Pinus koraierasis, Ginkgo biloba, Liriodeytdron tulipifera, Platanus occidentalis and their resistance to the pollutant toxicity in urban and industrial regions of Seoul and Taejon, Korea. Total sulfur content and superoxide dismutase activity were analysed in tree foliage of Pinus densiflora, Pinzes koraiensis, Ginkgo biloba, Liriodendron tulipifera, Platanus occidentalis. In addition, SOD activity was analyzed in the foliage of tree seedlings, i.e. Pinus densijlora, Pinus koraiensis, Ginkgo biloba, Liriodendron tulipifera, with the lurnigation of $SO_2$ in gas chamber 4 hours a day for six days. In all species total sulfur content and SOD activity had a positive correlation. Air pollutants accumulated in tree tissues were supposed to enhance the enzyme activity like SOD providing with the resistance mechanisms. Trees under the air pollution stress increased enzyme activity to develop internal self-resistance against pollutants, but after a critical point enzyme-activity decreased gradually and resulting in injury after all, Deciduous trees had greater filtration capacity than conifers and coniferous trees showed greater resistance against air pollutants than deciduous species. Foliage SOD activity was higher in polluted area than in unpolluted area for most species. Coniferous species and mature trees had higher SOD activity than deciduous seedlings. Especially Pinus koraiensis, Ginkgo biloba and Plcatanus occidentalis had higher SOD activity than other species. The tree species with the high SOD activity showed strong resistance against air pollutants. In 2nd-year needles of Pinus densiflora seedlings and current and 2nd-year needles of Pinus koraiensis seedlings containing high native SOD activity, SOD activity increased with the increase of $SO_2$ level. But in seedlings containing low native SOD activity, SOD activity increased at 0.5ppm $SO_2$ level while it decreased at 1.5 and 2.5ppm $SO_2$. Changes of SOD activity was different between species and in most species SOD seemed to participate in resistance mechanism.

• Journal of Korean Society for Atmospheric Environment
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• v.7 no.1
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• pp.55-65
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• 1991

The study was performed to select a adaptable tree species under stressed field conditions where there are a industrial plants operating with a number of smoke stacks emitting pollutants, such as hydrogen fluoride and sulfur dioxide. As a result of the study, a tree species selected are due to construct a forest belt in a zones near industrial plants to reduce the concentrations of air pollutants. The concentrations of atmospheric hydrogen fluoride and sulfur dioxide were very higher at experimental sites near industrial plants (air-pollution sites) than at control site. The leaves of 7 tree species grown at air pollution sites contained more sulfur and, specially, fluorine than at those control site. Among the tested tree species, Ligustrum japonicum Thunb. and Euonymus japonica Thunb. grown at air pollution sites did not at all break out a foliar injury but appeared to be healthy, as well as those grown at control site. Acer pseudo-sieboldianum Kom., Pinus virginiana Mill., Larix leptolepis Gordon., Pinus koraiensis Sieb. et Zucc., Pinus strobus L., Picea abies Karst and Ligustrum obtusifolium Sieb. et Zucc., however, showed a severe fluoride-type foliar injury such as necrosis on tip or margin of leaves, etc. Fluorine found in leaves was proved to be correlated to sulfur found in leaves whereas index of foliar injury hadn't a good correlation to pollutants found in leaves. It appears that Euonymus japonica Thunb., Ligustrum japonica Thunb., Platanus acerifolia Willd, Chamaecyparis pisifera Endl., Populus tomentiglandulosa T. Lee and Sophora japonica L. grown at both experimental sites had a high value of percent survival whereas Pinus virginiana Mill., Pinus koraiensis Sib. et Zucc., Koelreuteria paniculata Laxm. and Alnus hirsuta Rupr. had an extremely low value of that. In comparison with control site, the percent tree height increments in Chamaecyparis pisifera Endl., Ligustrum japonicum Thunb., Quercus acutissima Carruth., Populus tomentiglandulosa T. Lee, Pinus thunbergii Parl and Euonymus japonica Thunb. and the percent upmost root diameters in Populus tomentiglandulosa T. Lee, Chamaecyparis pisifera Endl., Euonymus japonica Thunb., Ligustrum japonicum Thunb., Betula platyphylla var. japonica Hara and Pinus thunbergii Parl. cultivated at air polluted sites showed very high value above 90%, respectively. A significant negative correlation (r=-0.662) was recognized between the index of foliage injury and the percent collective character, which was the mean of tree characters such as percent survival, percent tree height increment and percent upmost root diameter increment which compared to those at air polluted site with those at control site. Based on the percent collective character Ligustrum japonicum Thunb., Euonymus japonica Thunb., Chamaecyparis pisifera Endl., Populus tomentiglandlosa T. Lee, Betula platyphyla var. japonica Hara and Platanus occidentalis L. have large value about 90%, respectively. Therefore, the results indicate that this tree species are adaptable species in air polluted regions. For better understanding of the adaptable tree species, furthur studies concerning the effects of various air pollutants on the tree growth are required.