• Korean journal of applied entomology
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• v.16 no.2 s.31
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• pp.79-86
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• 1977

Four experiments were carried out under farmer's field conditions to determine economic threshold levels of major rice pests aad attempt a reduction in the number of insecticide applications. In the experiments were included check treatments, insecticide schedules representing the official recommendations to farmers, and several corrective treatments. A careful record was kept of insect pest densities and disease incidence. i) In the north at Suweon and Icheon where Chilo suppresalis. (Walk.), the striped rice borer, was active in the first generation, no significant yield differences were obtained between plots receiving several insecticide applications and those left totally unprotected. The mean yields were high (5.2-7.6t/ha). ii) First generation borer activity rising to $8.6\%$ injured tillers was below the economic threshold since no yield reduction was recorded in either japonica varieties or the high-yielding Tongil variety. iii) Evidence was obtained thst berer damage was made good by replacement of infested tillers (compensatory growth), C. suppressalis populations were always low in the second generation. iv) The experimental results obtained at Suweon and Icheon do not justify the present official recommendations of 6-7 pesticide applications. v) further south at Iri a substantial yield reduction occurred due to an early outbreak of stripe disease transmitted by Laodelphax striatellus (Fallen), the small brown planthopper; a mean of 1-2 individuals/hill was recorded immediately after transplanting. C. suppressalis probably contributed to this yield reduction. vi) Several applications against the vector failed to prevent the rapid spread of stripe to the susceptible variety in the Iri experiment: in surrounding fields the resistant Tonsil varivety was ralatively unaffected. vii) Pests of lesser importance were Nephotettix cinctieps (Uhler), Nilaparvata lugens (Stil), Sogatella furcifera (Horv..), and leaf miners.

• Korean Journal of Ecology and Environment
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• v.45 no.3
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• pp.289-301
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• 2012

A biological assessment of water quality was made at 9 sites of the Joyang-river and inflow streams located in Jeongseon-gun Gangwon-do, from June 2008 to September 2010. The investigation consisted of physico-chemical factors, biomass, and standing crops of epilithic diatoms. In addition, the community structure of epilithic diatoms was analyzed, and the water quality was assessed using DAIpo and TDI. The pH varied from 7.4~10.2 which is attributed to the Joyang-river area consisting of limestone. A total of 117 taxonomic groups of epilithic diatoms, including: 2 orders, 6 families, 23 genera, 95 species, 15 varieties, 2 forms, and 5 unidentified species, were found in the Joyang-river. 11 taxa, including Achnanthes laterostrata and Cymbella delicatula which live in neutral to alkali pH, were found. An indicator species of alkali waters, Cymbella delicatula, was routinely observed to have a relative frequency of over 10% in I3 and I4. In the result of the biological assessment using DAIpo, the Joyang-river was rated class A, with an average of 77.03 and inflow streams were rated class B with an average of 65.84. As for the results of TDI analysis, the Joyangriver was rated class A~B, and inflow streams were rated class A~D. Accordingly, the water quality of the Joyang-river was determined to be superior to that of inflow streams. Although the main stream showed low water quality at sites J2 and J3, correlating with a reduction in the quality of inflow stream, I1 in September 2009.

• Korean Journal of Environment and Ecology
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• v.23 no.2
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• pp.105-115
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• 2009

The naturalized plants in the Byeonsanbando National Park were listed 88 taxa composed of 24 families, 65 genus, 83 species and 3 varieties and 2 forms by field survey. The naturalized plants divided into pattern by survey of annual plants ratio is 38 taxa (43.2%) by life form spectrum and perennials is 28 taxa (31.8%), biennials is 19 taxa (21.6%), two trees (Robinia pseudoacacia, Ailanthus altissima) and one shrub (Amorpha furticosa) were founded. According to analysis results form place of origin, Europe covered 26 taxa (37.1%), North America covered 23 taxa (32.8%). Naturalized degree 3 plants, as common but not abundant, founded as 28 taxa (31.8%) were hold most highly ratio, naturalized degree 1 plants founded as 8 taxa (9.1%) were hold lowest. Introduction period 1 covered 39 taxa (44.3%) have had highest score and period 2 covered 16 taxa (18.2%) have had lowest scores. In addition, the urbanization index based on 271 taxa was 32.5% and Ambrosia artemisiaefolia is growing by ecosystem disturbing wild plants. Meanwhile, Ambrosia artemisiaefolia have confirmed into district of introduction in the Byeonsanbando National Park were damage the human body of plants develop an allergy to pollen. Therefore, management counterplan of the sequel of monitoring them might be required, introduction into naturalized plants are grasp of ecological characteristics and systematical management plan from this point of time by require.

• Journal of Life Science
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• v.25 no.11
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• pp.1244-1254
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• 2015

Naturalized plants were identified and recorded in Busan city based on field surveys and related literature. These plants consisted of 156 taxa in total, belonging to 31 families, 95 genera, 147 species, and 9 varieties. The Compositae had the highest diversity among 31 families, with 44 taxa, followed by Gramineae, with 24 taxa, and Leguminosae, with 10 taxa Among the plants, 68.6% (107 taxa) were annuals and biennials, and 30.1% (47 taxa) were perennials. There was one shrub (Amorpha fruticosa) and one tree (Robinia pseudoacacia). Naturalized degree 5 plants, as common and abundant plant, founded 26 taxa (96.3%) were most highly ratio from Korean naturalized plants. According to the results of the analysis based on place of origin, 50 (32.1%) taxa were from Europe, and 48 (30.8%) taxa were from North America. Epecophyten was the most common of the naturalized plants, with 123 taxa Sixty-six (42.3%) taxa were introduced during period 1, and 15 (9.6%) were introduced during period 4. Ergasiophygophyten (50.6%) and Kenophyten (32.1%) were the dominant plants in these introduction periods. In conclusion, Busan city acts as a conduit for the introduction of naturalized plants. A sustainable management and monitoring strategy may be needed to prevent the introduction and naturalization of plants.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.550-558
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• 2012

The naturalized plant species in Gyeongju National Park was summarized as 46 taxa including 14 families 40 genus 45 species 1 varieties. Among them, annual herbaceous species was 17 taxa (37%) which is grouped as the biggest proportion and 16 taxa (34.8%) for perennial herbaceous species and 11 taxa (23.9%) for biannual herbaceous species and 2 taxa(4.3%) for tree species. European origin was the biggest proportion as 17 taxa (37%), and 16% (34.8%) from North America. The degree of naturalization (DoN) was the biggest for Degree III, V as 18 taxa (39.1%). Regarding 321 naturalized plant species, the Urbanization Index in the studied area was 14.3%. The Namsam District showed 8.1% which is the highest DoN in the studied districts within the Gyeongju National Park. As the cultural properties is important in the Gyeongju National Park as a representatives for historical sites in Korea, planting and its management in the cultural properties is important tasks. The naturalized plant species in the studied area should be reasonably management.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.1
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• pp.45-54
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• 2018

This study aims to study the flora and identify the naturalized plants of the 4 ancient palace (Gyeongbokgung, Changdeokgung, Changgyeonggung, Deoksugung) and Jongmyo Shrine, which are national cultural heritage and urban cultural centers in Seoul. The plants found consisted of 315 taxa in total, belonging to 82 families, 201 genera, 285 species, 1 subspecies and 29 varieties. The naturalized plants were shown as follows: in the Deoksugung Palace(33 taxa), the Jongmyo Shrine(14 taxa) and the Gyeongbok Palace(21 taxa) and the Changdeokgung Palace complex(11 taxa). The results of the analysis based on the place of origin showed a higher rate of distribution of species based in North America, Europe and Eurasia, with higher rates of grass than tree. In addition, except for Gyeongbokgung Palace, the annual rate is higher than the perennial rate. As a result of naturalization analysis, the percentage of naturalized plants corresponding to naturalization degree 3 and naturalization degree 5 was high. According to the moment of the invasion, the naturalized plants recently introduced were higher than the first species. In addition, it was found that the similarity between the sites was more than 40%, and the diversity of species of naturalized plants common to the five sites was very low. The purpose of this study is to provide basic data for cultural heritage landscaping and naturalized plant management.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.280-285
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• 1991

The rice culture techniques of the ancient China which have played a key role directly and indirectly, in development of ancient farming and its techniques of Korea, were established before Christ in terms of dry-farming and the spirit of the farming-first principle. Especially techniques of rice culture were developed by cultivation methods for deep plowing, storage of water and preservation use of soil fertility. Therefore, the techniques of transplanting methods, seeding in rows, use of iron-made farming tools and dam construction for irrigation were advanced. And rice varieties were differentiated to avoid disasters or to supply of rice for various uses in many areas. Also, because north China was the origin of Chinese agriculture in which population density was low and flat land was wide that were the cradle of Chinese agriculture, ‘Hwayungsunubeob’(firing and drawning weed control method) and fallowing were quickened as intensive techniques of rice culture. In connection with the view of agricuture with 'the theory of the cosmic dual forces and the five primary substances' of Han Mooje and Chamwye scholars, the techniques of seeding and selection of crops were gradually developed. From ‘Jeminyosul’ of the 6th century to ‘Wangjongnongseo’ of the 14th century, the techniques of rice culture have been developed continuously and additively, but were not improved thereafter Won dynasty. From this point of time, the time of agriculture in the end of Koryo age and by ‘Nongsajiksul’ were initiated.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.278-285
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• 2012

Cymbidium goeringii is one of the most important and popular species in the orchid family in north-east Asia. In the present study, we prepared multiplex PCR system, and used it for the genotyping of eight simple sequence repeats (SSR) markers (CG409, CG415, CG709, CG722, CG787, CG1023, CG1210, and CG1281) in subject with 40 samples of cultivated varieties. All the analyzed samples showed different combined genotypes. The average combined power of discrimination was very high value of $7.14{\times}10^{-10}$, and observed heterozygosity (Ho = 0.466) was similar with two wild populations of C. goeringii, which may indicate no or little occurrence of genetic change after collection from wild habitats. The present study also developed a two-dimensional barcode to express information of genotype results of eight SSR markers (SSR DNA ID). The discrimination power of DNA ID between two individuals will be statistically more than 99.999999%. The SSR DNA ID and two-dimensional barcode may be very usefully applied for the discrimination and maintence of cultivars of C. goeringii.

• Journal of Environmental Impact Assessment
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• v.23 no.4
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• pp.315-322
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• 2014

After the modern industrial revolution, rivers in cities became covered and disappeared due to the pressure to develop them. Likewise, their function which is to serve as the basis of natural ecology system in the cities began to be damaged. This research demonstrated that there are a total of 268 categories when it comes to the list of plants, including 64 families, 179 genera, 230 species, 36 varieties, and 1 subspecies. When the relative abundance of the plants that were found at the target research site was studied, the secondary survey demonstrated Bromus japonicus 22.97, Artemisia princeps var. orientalis 16.76 and Erigeron annuus 15.69 while third survey demonstrated Digitaria ciliaris 26.78, Ambrosia trifida 16.29 and Aster pilosus 14.31. There were 54 species of naturalized plants that appeared. Analysis demonstrated annual plant 23 classification category (43%), perennial 11 classification category (20%), multi-perennation 17 classification category (31%), woody plant 3 classification category (6%) and others. When the naturalized plants that were found at the target research site were analyzed by the place of origin, North America and EU took up 76%, which accounts for 3/4 of the all the naturalized plants. At the target research site, naturalization degree of 5 pertained to 22 classification category (41%), which was the highest, followed by 19 classification category (35%) with naturalization degree of 3, 8 classification category (15%) with naturalization degree of 2 and 5 classification category (9%) with naturalization degree of 4 in the order mentioned. Flora of Jungnangcheon did not manifest any change compared to 10 years ago. Thus, it is necessary to increase of biodiversity efforts to improve SeoulCity's natural environment and cityscape.

• Korean Journal of Plant Resources
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• v.19 no.5
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• pp.640-648
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• 2006

The distribution and status of naturalized plants in Jeju Island were investigated in this study. As results, the naturalized plants in Jeju Island were total of 254 taxa including 47 families, 161 genera, 248 species and 6 varieties. By the growth habits, annuals held the most percentage including 107 taxa (42.13%). Seventy nine taxa (31.1%) were appeared to have erect type in growth forms and 203 taxa (79.9%) are non-clonal growth form in disseminule forms by radicoid. The most of dormancy form in life form were therophytes as 150 taxa (59%), and following as 53 taxa (20.9%) for hemicryptophytes, and 26 taxa(10.2%) for geophytes. Among the naturalized plants, 115 taxa (36.7%) were originated from Europe, 69 taxa (22%) from Asia and 59 taxa (18.8%) from North America. Twenty eight percent of them were introduced as feeds or mixed seeds of imported cereals.