• Korean Journal of Weed Science
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• v.4 no.1
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• pp.96-106
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• 1984

Changes in weed floras and development of plant resistance to herbicides seemed to be closely related with increased and repeated use of herbicides. Herbicide use increased from 5% of the total consumption of pesticide in 1950 to 45% in 1976 in world basis. About 200 herbicides have been introduced to agriculture so as to control about 206 weed species which have been recorded important to human beings. In Korea, there was about 351 times in increased use of herbicides from 1966 to 1982. Interspecific selection by herbicide is mainly responsible for changes in weed floras and resulted in varying tolerance or susceptibility to herbicides, together with the changes of agricultural practices. The present trend toward continuous cereal cultivation throughout world will lead to type of changes in weed floras favorable to therophyte which can survive under unfavorable conditions as seeds rather than the types of geophyte which can survive unfavorable seasons as buds placed below soil surface. However, geophyte such as Sagitaria pygmaea, and Scirpus jurtcoides, and Cyperus rotundus and Cynodon dactylon in temperate warm climate become severe paddy weeds, presumably because of the removal of annual weeds by herbicides. Since differential tolerance to 2,4-D was firstly reported in Agrostis stolofera, about 30 species of weeds in 18 genera are presently known to have developed resistance to triazine herbicides. Resistance of weed biotypes to triazine herbicide is not mainly due to limited absorption and translocation or to the difference in metabolism, but is the result of biochemical changes at the site of metabolic activity, such as a loss of herbicide affinity for triazine binding site in the photosystem II complex of the chloroplast membrane. Genetical study showed that plastid resistance to triazine was wholly inherited through cytoplasmic DNA in the case of Brassica campestris. Plant tissue culture method can be utilized as an alternate mean of herbicide screening and development of resistance variants to herbicides as suggested by Chaleff and Parsons. In this purpose, one should be certain that the primary target process is operational in cell culture. Further, there are a variety of obstacles in doing this type of research, particularly development of resistance source and it's regeneration because cultured cells and whole plants represent different developmental state.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.3
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• pp.188-197
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• 2021

This study aimed to obtain fundamental data for demonstrating biodiversity of vegetation of East Asian alder (Alnus japonica) Forest Wetland of Heonilleung Royal Tombs. A total of 166 vascular plants (159 species, three subspecies, three varieties, and one cultivar) belonging to 132 genera and 59 families were found, accounting for 8.3% of 1,996 vascular plant species found in Seoul. Therophyte was the most common life-form of plants in Heonilleung Wetland. As for rare plant species, one Least Concern (LC) species was found. There were 15 floristic regional indicator species in the research area. Three of them belonged to floristic grades III and IV. This indicates that their habitats are discontinuous and isolated to some degree. Nineteen invasive alien plant species were found, most of which were introduced from North America after the year 1964 with a spread rate of V (widespread, WS).

• The Korean Journal of Ecology
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• v.18 no.1
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• pp.31-41
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• 1995

Floral analysis about vegetation of Kimpo landfills and its periphery region was carried out. The study area was defined to a square $(81km^2)$ of which center was located at 250m in front of Andongpo, Komdan-myon, Kimpo-gun in the northwest part of the Kyunggi Province. This study was accomplished by analyzing five qualitative traits such as ecological strategy, reproductive strategy, distribution type, native/foreign division and life-form throughout actual investigation of the flora. The flora was composed of 536 taxa which comprise 105 families, 343 genera, 458 species, 1 subaspecies, 70 varieties and 7 forms (including 92 species of horticultural plant). Lythrum salicaria community, Spiraea salicifolia community, ottelia alismoides community and woods of Alnus japonica were recorded ？ 새 retrictive distribution according to habitat characteristics. Owing to severe anthropogenic interferences such as construction of the Kimpo landfills in the study areas, a high proportion of ruderal plants and neophytes in the floral composition was recognized. The proportion of individual distribution type and therophyte was very high throughout whole study areas, and plant communities in the reclaimed areas were characterized by high proportion of phalanx plant species. Analysis of the correlations between meshes with ecological traits of plant species showed that Kimpo landfills and its periphery region was divided into two vegetation types, coastal type and inland type, as a result of possible saline effects.

• Journal of Environmental Science International
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• v.18 no.11
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• pp.1309-1324
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• 2009

This study was survey a flora and life form spectrum of 11 uninhabited islets, in jeju-do. The vascular plants of each uninhabited islets were summarized as Beomseom 159 taxa, Chagwi-do 136 taxa, Daryeo-do 81 taxa, Hyeongje-do 61 taxa, Jigwi-do 39 taxa, Munseom 147 taxa, Ran-do 58 taxa, Saeseom 65 taxa, Seogeondo 60 taxa, Seopseom 183 taxa and Wa-do 46 taxa. Floristic richness was in order analyzed to be Seogeon-do 28.62, Ran-do 19.24, Daryeo-do 18.53, Wa-do 16.42, Munseom 16.14, Hyeongje-do 14.76, Seopseom 13.32, Beomseom 13.24, Chagwi-do 6.15, Saeseom 5.86 and Jigwi-do 2.51. Life form spectrum was surveyed to H-$D_5$-$R_4$-e; hemieryptophyte(H) 26.8%, not production seeds($D_5$) 54.4%, clonal growth by stolons and struck roots($R_4$) 46.9% and erect form(e) 30.3%. According to the life form spectrum hemieryptophyte dominated high portions, which suggests islet in jeju-do has hemieryptophytic climate and similar to middle parts in Korean Peninsular. However, were noticed by that it has more therophytes. As a result, Partially shows the characteristics change from the temperate climate to the warm temperate climate or a semitropical climate by a climatic change.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.284-293
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• 2016

In order to assess th changes in vegetation characteristics over time in the forest-lands which is isolated by urbanization, vegetation surveys based on the Braun-Blanquet phytosociological method was carried out in 1996 and 2015 on Mt. Hwangyeong located in the center of Busan metropolitan city, South Korea. The number of vegetation types based on floristic composition showed no significant changes, the vegetation units under the community levels was more or less represents the difference. the average total vegetation cover and average number of species per unit area ($100m^2$) was increased 16% and 2 species, respectively. The relative importance value (RIV) for each tree species, Quercus spp. like as Q. mongolica and Q. serrata was decreased, while the warmth-tolerant trees, evergreen broad-leaved trees, and mesophyte like Lindera erythrocarpa, Styrax japonica, Osmanthus heterophyllus, and Stephanandra incisa was increased significantly. Changes of the life form spectrums of vascular plants did not substantially, hemicryptophyte(H) and therophyte (Th) was decreased, while nanophanerophyte(N) was increased significantly. Also through the creating of large-scale vegetation map (based on physiognomic vegetation types) was compared the spatial distribution characteristics of each vegetation types.

• Korean Journal of Environment and Ecology
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• v.16 no.3
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• pp.271-286
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• 2002

To understand the status of vegetational composition of Jungnangcheon, 21 plots in 7 sites were investigated in June 2001 and flora survey was done during the period from June to September 2001. The results obtained from this study were as follows: Vegetational compositions of 7 sites in Jungnangcheon area were different site by site and plot by plot. In lower(nearest) point, Phalaris arundinacea, Potentilla supina, Rorippa islandica, Chenopodium album, Beckmannia syzigachne and Chenopodium ficifolium showed higher constancy and frequency. Bromus japonicus, Humulus japonicus, Conyza canadensis, Elymus tsukusiensis var. transiens showed higher constancy and frequency in middle point and Bromus japonicus, Chenopodium ficifolium, Artemisia princeps var. orientalis showed in upper point. Bromus japonicus, Chenopodium ficifolium, Humulus japonicus, Conyza canadensis, Elymus tsukusiensis var. transiens, Artemisia princeps var. orientalis and Lepidium uirginicum appeared at more than 9 polts in 21 sample plots. Number of naturalized plants in Jungnangcheon area were 79 taxa. Total naturalized index(NI) and urbanized index(UI) were recorded as 29.2%, 27.9%. 253 taxa including 50 families 169 genera 224 species 1 subspecies 27 varieties 1 forma were recorded in Jungnangcheon area. Therophyte(Th) was the most common dormancy form recorded in survey area. Geophyte(G) and Hemicryptophyte(H) were calculated as 7.1%, 17.8% and it was the lower value compared to those of other dormancy form. Consequently, Th-R$_{5}$-D$_4$-e was recorded as the most common life form in Jungnangcheon.

• Journal of Wetlands Research
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• v.14 no.1
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• pp.59-73
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• 2012

The importance of rice paddy wetland has been raised since the 10th Ramsar Convention in 2010. However, there is shortage of study on the evaluation of rice paddy wetland and also of the study on the effect of organic agriculture on the vegetation characteristics. Accordingly, this study examined the vegetation characteristics of organic rice paddy for the basic resources of evaluating value of rice paddy wetland. 6 places of organic rice paddy and conventional rice paddy were chosen as research targets. It analyzed the function of 'Floral Diversity and Wildlife Habitat' among the revised RAM, an existing wetland evaluation system. As to the factor affecting the analysis result, simple land-use result was proved to determine the evaluation. As a result of vegetation investigation total 176 taxa, 53 families, 146 generics, 148 species, 26 varieties and 1 forma. When the difference of appearance of life form between organic area and conventional area was examined, organic paddy had higher appearance of life form in Therophyte and Megaphanerophyte. For the distribution of Naturalized plants, organic rice paddy had lower naturalized rate and urbanization index than conventional rice paddy. As to the Pearson correlation analysis between growing condition and vegetation characteristics, variety of rice paddy vegetation showed it was not heavily influenced by the land use. However, the organic rice paddy area had more variety in vegetation than conventional rice paddy. There was about 1% correlation with types of Cyperaceae, which means that the classification group of Cyperaceae can be utilized in evaluating rice paddy wetland later on. It is determined that the wetland evaluation has been widely influenced by soil environment, water environment and surrounding natural and artificial landscape as well as vegetation characteristics. Accordingly, further research seems to be required with minute investigation to an extensive area.

• Korean Journal of Environmental Agriculture
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• v.33 no.2
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• pp.86-102
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• 2014

BACKGROUND: According to the types of human interference, there are various plants that have strong vitality and ability to breed in the dry field. Recently, climate change alters the geographical distribution and phenology of the plant species. So, we need to understand present occurrence pattern and ecological characteristics of these plants. METHODS AND RESULTS: The plant species data were obtained from 8 regions in Jeolla-do. Flora investigation was done from May 2013 to September 2013. Habitat type of dry field in Jeolla-do was classified into 3 types (inside of dry field: IDF, embankment around the end of a dry field: EDF, levee slope of dry field: LS). The vascular plants of study area were listed 296 taxa which contain 68 families, 203 genera, 244 species, 43 varieties and 9 forms. The vascular plants of three different habitat types were IDF 174 taxa, EDF 249 taxa and LS 136 taxa. The occurrence rate of Therophyte was arranged by the order of IDF(67.6%), EDF(51.9%), LS(54.3%). Naturalized rate was analysed as IDF 27.9%, EDF 21.0%, LS 18.6%. Urbanization index was analysed as IDF 11.8%, EDF 13.7%, LS 10.0%. CONCLUSION: With these results, we found that three habitat types were ecological difference affected by the human impacts. Also, we found environmental indicators through the ecological characteristics of flora for the type of habitat of dry field. These indicators will help assess the agriculture environmental variability and the floral change according to the climate change in dry field.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.63-72
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• 2016

The objective of this study was to identify the life form characteristics, naturalized degree and introduction period of naturalized plants on upland fields in South Korea. The survey sites were selected in 222 upland fields over 9 provinces where are relatively dry soil conditions and are disturbed continuously by farming practices. It seemed that these uplands maintain good condition for the invasion and settlement of alien plants. Field surveys were carried out twice from May to June and from August to September in 2013. The vascular plants of the upland fields were listed into 539 taxa which contain 103 families, 320 genera, 448 species, 2 subspecies, 74 varieties and 15 forms. Ninety nine taxa were naturalized plants composed of 23 families, 64 genera, 91 species and 8 varieties. The urbanization index and naturalized index is 30.65% and 18.37%, respectively. Among total 99 naturalized plants, Compositae (30 taxa) was the most dominant family, and followed by Gramineae (14 taxa). On the basis of dormancy form, 78 taxa were belong to Th (Therophyte). In radicoid form, $R_5$ plants (86 taxa) and $R_3$ plants (14 taxa) were dominantly distributed. In disseminule form, $D_4$ including 63 taxa and $D_2$ containing 26 taxa were dominant. On the basis of growth form, erect form (e) containing 26 taxa was dominant. In conclusion, life form spectrum was $Th-R_5-D_4-e$ type. According to life form analysis, naturalized degree and introduction period, alien plants with unique characteristics may have high ability to settle and spread nationwide after inflow into South Korea. It needs further to observe some plant species with or without ecological features such as widely disseminated seeds by wind or water, high seed productivity, long life-span seeds, high germination rate of seeds, or non-dormant germinable seed.