• Korean Journal of Ecology and Environment
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• v.35 no.4 s.100
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• pp.273-284
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• 2002

During January 1998-October 1999, the impact of free-floating plants (FFP) on limnology of the wetland ecosystem was evaluated through the investigation of physicochemical characteristics of the Woopo Wetland along with in situ manipulation experiments of aquatic plants. Flooding events occurred in the wetland during the summer period (Jun.-Aug.) and water levels rose to 2-3 m due to precipitation from the catchment and inflow from the main channel of the Nakdong River. Physicochemical parameters and plankton dynamics in the wetland during the summer were greatly influenced by floods and growth of free-floating plants. Dissolved oxygen (Jun.-Sept., 4.5${\pm}$2.5 mg/1; Oct.-May, 8,1 ${\pm}$4.0 mg/1) and pH (Jun.-Sept., 6.9${\pm}$0.4; Oct.-May,7.4${\pm}$0.8) levels were significantly lower during the summer than any other seasons. Three types of enclosure experiments (100 L, treatments with floating plants, screened and opened) were conducted under the presence and absence of sediment for 15 days in the 1999 summer. The treatments with sediment had higher levels of nutrient concentrations than those of the others. Among the treatments with sediment, nutrient concentrations in the treatments with free-floating plants were higher than the others. Zooplankton communities in each treatment showed a similar variation, although the scale of zooplankton densities differed. Rotifer community dominated the zooplankton at the initial phase of the experiment, but decreased drastically along with an increase of cladoceran and copepod communities. In conclusion, low levels of dissolved oxygen and pH in the Woopo Wetland during the summer seemed to be caused by a proliferation of free-floating plants and active decomposition process at the bottom of the sediment.

• The Korean Journal of Ecology
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• v.23 no.3
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• pp.201-209
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• 2000

The flora, distribution area, vegetation structure, annual net primary production, and nutrient uptake of the vascular hydrophytes, hygrophytes and mesophytes were investigated in the wetlands of the Asan-Lake, Chungchongnam-do and Kyonggi-do, Korea from March to October in 1997 to reveal the correlation between the plant community and the lake environment. The flora was composed of 38 families, 89 genera, 106 species, 14 varieties or total 120 kinds of the vascular plants. The life from of the hydrophytes were classified as 14 kinds of emergent plants, 5 kinds of submerged plants, and 4 kinds of free-floating plants, respectively. The number of species was various to 4 ∼85 kinds in each site. The dominant species was Zizania latifolia, and the importance values of Zizania latifolia, Typha orientalis, Phragmites communis, and Spirodela polyrhiza were 39.58, 14.90, 13.97, and 7.64, respectively. The distribution area of the emergent hydrophytes, hygrophytes, and mesophytes was 49.3 ㏊ (90.5%), and free-floating plants was 5.2 ㏊ (9.5%), whereas the floating-leaved and submersed plants were rare. Annual net production of the emergent hydrophytes, hygrophytes, and mesophytes was 547.9 ton D.W./yr (98%), and those of the free-floating plants was 10.5 ton D.W./yr (2%), and 558.4 ton D.W./yr in the whole lake ecosystem. The total uptake of nitrogen and phosphorus by the vascular plants was 7,099 and 1,891 ㎏/yr in the whole lake ecosystem.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.2
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• pp.59-81
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• 2011

The flora of the Sinpyeong and Churyeong stream were listed 324 taxa; 87 families, 227 genera, 289 species, 1 subspecies, 31 varieties and 3 forms. The Sinpyeong stream were 249 taxa and Churyeong stream were 221 taxa. Based on the rare plants (IUCN) by the Korea Forest Service and Korea National Arboretum were recorded; Penthorum chinense (Crassulaceae), etc. and endemic plants, 6 taxa; Weigela subsessilis (Caprifoliaceae), Lycoris flavescens (Amarylidaceae), etc. Based on the specific plants by floral region were total 12 taxa (3.7% of all 324 taxa of flora); Monochoria korsakowi (Pontederiaceae), etc. in class III. 10 taxa (Salix glandulosa (Salicaceae), Ulmus parvifolia (Ulmaceae), Impatiens noli-tangere (Balsaminaceae), Grewia biloba var. parviflora (Tiliaceae), Nymphoides peltata (Gentianaceae), Actinostemma lobatum (Cucurbitaceae), Cirsium pendulum (Compositae), Microstegium japonicum (Gramineae), etc.) in class I. Based on the naturalized plants, 51 taxa and ecosystem disturbing wild plants, 6 taxa (Rumex acetosella, Sicyos angulatus, Aster pilosus, Ambrosia artemisiaefolia, Hypochaeris radicata, Paspalum distichum var. distichum) and naturalization rate was 15.7% of all 324 taxa of flora, urbanization index was 18.8% of all 271 taxa of naturalized plants. Based on the hydrophytes, 23 taxa and emergent hydrophytes were 17 taxa, floating-leaved hydrophytes were 3 taxa, submergent hydrophytes were 2 taxa, free-floating hydrophytes was Spirodela polyrhiza.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.4
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• pp.25-42
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• 2018

The purpose of this study is to present the basic data for management of ecologically restored stream by surveying and analysing the vascular plants distributed in Chunghyocheon stream, Gyeongju-si. The survey of vascular plants in this site was conducted before and after restoration. The number of vascular plants were summarized as 276 taxa including 68 families, 188 genera, 242 species, 1 subspecies, 29 varieties and 4 forms. The rare plants were 2 taxa including Prunus yedoensis Matsum. and Iris ensata var. spontanea (Makino) Nakai, and the Korean endemic plant was Lespedeza maritima Nakai. The specific plants by floristic region were 13 taxa including 1 taxa of grade V, 3 taxa of grade III, 1 taxa of grade II and 8 taxa of grade I. The naturalized plants were 62 taxa including Persicaria orientalis (L.) Spach, Lepidium virginicum L., Poa compressa L. and so forth. The invasive alien plants were 3 taxa including Ambrosia artemisiifolia L., Aster pilosus Willd. and Lactuca scariola L.. The hydrophytes were 34 taxa including 26 taxa of emergent plant, 1 taxa of floating-leaved plant, 2 taxa of free-floating plant and 5 taxa of submerged plant.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.303-311
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• 1999

This study had been performed to clarify the distribution of specific plants and hydrophytes in the 27 sites of drainage basins located in Youngsan River at the period of June 1997 to July 1999. Hydrophytes were composed of 32 familis 86 species and hygrophytes 36 familis 135 species. Among hydrophytes, emerged plant, floating-leaved plant, submerged plants and free floating hydrophytes were 52, 15, 12, and 7 species respectively in this investigation. Threatened species were Drosera rotundifolia, Utricularia racemosa, Utricularia bifida, Utricularia japonica, Hydrocharis dubia, Endangered species were Brasenia schreberi and Euryale ferox.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.2
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• pp.67-90
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• 2024

The purpose of this study is to present the ecological data for conservation and management of three wetlands by surveying the vascular plants in Ganam reservoir, Ahnshim wetland and Jeomsae swamp. The whole taxa of vascular plants were 376 taxa including 90 families, 252 genera, 341 species, 7 subspecies, 24 varieties, 2 forms, 1 hybrid and 1 cultivar, and the planted species were 66 taxa including Ginkgo biloba and so on. The rare plants were 7 taxa including Euryale ferox(VU), Aristolochia contorta(LC), Koelreuteria paniculata(VU), Sagittaria trifolia(DD), Hydrocharis dubia(LC), Ottelia alismoides(LC) and Sparganium stoloniferum(VU). The Korean endemic plant was 1 taxon of Lespedeza maritima. In total, there were 21 taxa of floristic target species including 1 taxon of garde V, 2 taxa of grade IV, 6 taxa of grade III, 5 taxa of grade II and 7 taxa of grade I . The hydrophytes were 51 taxa including 36 taxa of emergent species, each 6 taxa of floating-leaved and submerged species and 3 taxa of free-floating species. The invasive alien plants were 79 taxa including 75 taxa of naturalized plants and 4 taxa of casual alien plant. The ecosystem disturbing species 6 taxa including Sicyos angulatus, Ambrosia artemisiifolia, Lactuca seriola, Symphyotrichum pilosum, Paspalum distichum and Humulus scandens.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.2
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• pp.61-77
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• 2017

The purpose of this study was to offer the basic data for conservation of wetland ecosystem by surveying and analysing the vascular plants distributed in Hwapocheon wetland, Gimhae, Gyeongnam, Korea. The numbers of vascular plants were summarized as 292 taxa including 72 families, 192 genera, 262 species, 1 subspecies, 26 varieties and 3 forms. There were 34 taxa of hydrophytes, 23 taxa of emergent plants, 4 taxa of floating-leaved plants, 5 taxa of free-floating plants and 5 taxa of submerged plants. The rare plants were 7 taxa including Aristolochia contorta, Penthorum chinense, Prunus yedoensis(planting), Ixeris tamagawaensis, Hydrocharis dubia, Iris ensata var. spontanea(planting), Acorus calamus and so forth. The Korean endemic plants were 2 taxa including Salix koriyanagi and Salix pseudolasiogyne. The specific plants by floristic region were 19 taxa including 2 taxa of grade V, 1 taxa of grade IV, 5 taxa of grade III, 2 taxa of grade II and 9 taxa of grade I. The naturalized plants were 62 taxa including Chenopodium album, Astragalus sinicus, Helianthus tuberosus, Panicum dichotomiflorum and so forth. The plants that were expected to spread nationwide were 14 taxa including Cerastium glomeratum, Bidens frondosa, Tagetes minuta, Festuca arundinacea and so forth. The invasive alien plants were 6 taxa including Rumex acetosella, Sicyos angulatus, Ambrosia artemisiifolia, Ambrosia trifida, Aster pilosus and Lactuca scariola.

• Journal of Wetlands Research
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• v.11 no.2
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• pp.17-28
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• 2009

The investigated Varcular plants in Youngsan River Streams of Downtown in Gwangju Metropolitan City consist of total 437 taxa: 2 forms, 49 varieties, 386 species, 265 genera, 91 families. Among 53 taxa of hydrophytes, emerged plants were 16taxa, floating-leaved plants were 10taxa, suvmerged plants were 10taxa, and free-floating plants were 3taxa and swamp plants were 14taxa. Based on the list of Rare and Endangered plants, 5taxa were recorded such as Hydrocharis dubia, Euryale Ferox, Penthorum chinense, Prunus yedoensis, Nymphoides coreana. And Korean endemic Plants were appeared as 5taxa: Poa annua, Forsythia koreana, Paulownia coreana, Galium koreanum, Aster koraiensis. From the specific plant species sorted by classes, class I has 10taxa, class II has 2taxa, class III has 2taxa, class IV has 3taxa, class V has 5taxa. Naturalized plant were listed as 62taxa: 15families, 44genera, 59species, 3varieties, and naturalization index was 14.19%. The ecosystem disturbance plants assigned by the Ministry of Environment, 3taxa were recorded: Paspalum distichum, Ambrosia artemisiifolia var. elatior, Solanum carilinense.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.3
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• pp.333-347
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• 2013

The present study numerically models the interaction between a regular wave and the roll motion of a rectangular floating structure. In order to simulate two-dimensional incompressible viscous two-phase flow in a numerical wave tank with the rectangular floating structure, the present study used the volume of fluid method based on the finite volume method. The sliding mesh technique is adopted to handle the motion of the rectangular floating structure induced by fluid-structure interaction. The effect of the wave period on the flow, roll motion and forces acting on the structure is examined by considering three different wave periods. The time variations of the wave height and the roll motion of the rectangular structure are in good agreement with experimental results for all wave periods. The present response amplitude operator is in good agreement with experimental results with the linear potential theory. The present numerical results effectively represent the entire process of vortex generation and evolution described by the experimental results. The longer wave period showed a different mechanism of the vortex evolution near each bottom corner of the structure compared to cases of shorter wave periods. In addition, the x-directional and z-directional forces acting on the structure are analyzed.

• Journal of Wetlands Research
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• v.6 no.3
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• pp.107-118
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• 2004

The flora of the vascular hydrophytes and hygrophytes and the change of flora according to the fluctuation of the water level before and after flooding were investigated from September 2002 to October 2003 in Woopo Wetland and Topyeong Stream, Changnyeong-gun, Gyeongsangnam-do, Korea. The flora of the Woopo, Mokpo, Sajipo, Jokjibyeol, Topyeongcheon Upstream, and Topyeongcheon Downstream were composed of 256, 242, 265, 177, 201, and 180 taxa, respectively. The flora of total study area was 86 families, 232 genera, 302 species, 42 varieties, 6 form, or total 350 taxa. Among them, hydrophytes, hygrophytes, and others were 36, 96, and 218 taxa, respectively. The life form of the vascular hydrophytes was classified as 19 taxa of emergent plants, 6 taxa of floating-leaved plants, 4 taxa of free-floating plants, and 7 taxa of submersed plants. The specified wild plants designated by the Korean Association for Conservation of Nature, Ministry of Forest, and Ministry of Environment were Euryale ferox, Hydrocharis dubia, Persicaria amphibia, Acorus calamus var. angustatus. And Aristolochia contorta was distributed in the study area. The floras of the naturalized plants of the Woopo, Mokpo, Sajipo, Jokjibyeol, Topyeongcheon Upstream, and Topyeongcheon Downstream were composed of 27, 25, 35, 21, 26 and 24 taxa, respectively. The flora of the naturalized plants of total study area was 43 taxa, this equalled 12.3% of total vascular plants in the study area. And 165~244 taxa were surveyed in the each study area before flooding, total 299 taxa, and 86~212 taxa after flooding, total 299 taxa. Among them, hydrophytes, hygrophytes, and others were 33 and 29, 93 and 83, 183 and 187 taxa before and after flooding, respectively. Before and after flooding, the species number of emergent plants, floating-leaved plants, free-floating plants, and submersed plants was nearly the same. It was guessed that vascular hydrophytes and hygrophytes adapted to fluctuation of the water level in the study area.