• Clean Technology
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• v.7 no.2
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• pp.89-97
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• 2001

The purpose of this study was to find the optimum condition of the high removal efficiency of water pollutant as sewage treatment technology using a filtering bed charged with porous sintering-pellet which was planted with hydrophytes. Experiment was carried out by changing concentration of water pollutants(COD, T-N, T-P), kind of hydrophyte, kinds of filtering material and size, and HRT. The result of removal efficiency was obtained as following: COD removal 73.8~87.1% for input concentration range of 50~450mg/L, T-N removal 61.3~77.3% for input concentration range of 7~124mg/L, T-P removal 89.5~99.1% for input concentration ranger of 3~27mg/L. In a comparative experiment of three kinds of hydrophyte(Iris pseudoacorus, Phragmites communis $T_{RIN}$., Oenanthe javanica Dc.), the best removal efficiency of COD and T-N was gained with Iris pse-udoacorus, and Phragmites communis $T_{RIN}$ showed better result than two hydrophytes for the removal efficiency of T-P. In a comparative experiment of four kinds of filtering-materials, the removal efficiencies were in the order of porous sintering-pellet, gravel, nonused-tire and nonused-concrete. It was found that for the porous sintering-pellet, the smaller its diameter, the better its result. In the filtering bed in which was charged with porous sintering-pellets of 5mm diameter and planted with Iris pseudoacorus, the removal efficiency of COD, T-N and T-P were over 80%, 70% and 90% under the concentration of COD 250mg/L, T-N 70mg/L and T-P 15mg/L for 24hrs treatment. Thus, we concluded that a filtering bed charged with porous sintering-pellet and planted with hydrophytes will be suitable for treatment of sewage water as a pro-natural treatment technology.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.200.1-200
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• 1998

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.140.1-140
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• 1999

No Abstract, See Full Text

• Journal of Forest and Environmental Science
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• v.16 no.1
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• pp.50-68
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• 2000

This study was to estabilish the composition and vegetation of vascular plants on natural mashes in Wondae-ri(710m: $37^{\circ}$ 58' 30" N, $128^{\circ}$ 12' 15" E), This work was conducted from April to October, 1999. Vascular plants were composed of 71 families, 175 genera, 228 species, 1 subspecies, 33 varieties and 3 formae, totaling 265 taxa. Among the investigated vascular plants, 19 families, 24 genera, 31 species, 5 varieties, 1 formae, totaling 37 taxa (13.9%) were hydrophytes and hygrophytes. The forest vegetation was classified into 1 community and 2 subcommunities ; A. Phragmites japonica community A-1. Salix gracilistyla-Impatiens noli-tangere subcommunity A-2. Spiraea prunifolia var. simpliciflora-Artemisia capillaris subcommunity.

• Korean Journal of Environmental Agriculture
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• v.35 no.2
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• pp.148-151
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• 2016

BACKGROUND: There are few studies on the impacts of hydrophytes on water quality, so there is a need to research the effects of death of hydrophytes on the worsening of water quality. This study aimed to monitor the effects of Trapa japonica death on reservoir water quality.METHODS AND RESULTS: T.japonica shows the life cycle that highest growth in summer and rapid death in fall decomposing their body in general. T.japonica contains comparatively large portion of nutrients and minerals. Through the field survey using Mesocosm to identify the effects of excessive population of T.japonica on water quality, the water quality of plots planted T.japonica is gradually worse compared with the control plot. And the result of Wilcoxon-test also shows that the negative effect of T.japonica on water quality with significant (p<0.05).CONCLUSION: It is necessary to control the population growth of T.japonica in order to prevention of water pollution in fall.

• The Korean Journal of Ecology
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• v.21 no.5_1
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• pp.435-448
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• 1998

The phytosociological investigation was carried out at 32 sites of the riparian vegetation in Musim-Chon stream passed through Choengju-City, Chungcheongbuk-Province by Braun-Blanquet's method from August to October, 1997. The flora of vascular plants in this survey was 202 species. The riparian vegetation was classified into 25 communities as follows. The submerged hydrophytes are Potomogeton malaianus var. latifolius community, Potomogeton crispus community, Myriophyllum verticillatum community-Hydrilla verticillata community and Ceratophyllum demersum community. The floating-leaved hydrophyte is Trapa japonica community. The emerged hydrophytes are Phragmites communis community, Perzicaria thunbergii community, Phragmites japonica community, Oenanthe javanica community, Zizania latifolia community and Persicaria hydropiper community. The herbaceous vegetation of floodplain are Artemisia montana community, Humulus japonicus community, Miscanthus sacchariflorus community, Erigeron anmus community, Impatiens balsamina community, Bidens frondosa community, Setaria viridis community, Ambrosia artemisiifolia var. elatior community and Eragrostis ferruginea community. The woody vegetation of floodplain are Robinia pseudo-acacia community, Stephanandra incisa community and Clematis apiifolia community. The species diversity was low in the upper and down stream, while the diversity was high in the mid stream situated at the center of Choengju-City because of frequent disturbance by citizens. These results suggested that distribution of communities and species diversity was closely related to the disturbance.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.335-345
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• 2005

A study on changes on the distribution of vascular hydrophytes and the growth pattern of Schenoplectus triqueter (Scirpus triqueter) was undertaken at the Nakdong River estuary from 2002 to 2004. The change was due to physical alteration of the estuary for the past 25 years. These plant species are the major food sources for winter waterfowl. A total of 32 species of vascular hydrophytes from 17 families were found in the West Nakdong River (freshwater), the main channel of Nakdong River (freshwater) and the Nakdong River Estuary (brackish water). After the construction of the barrage on the estuary in 1987, the number of hydrophytes has remarkably increased to 17 species (5 species in 1985) in the main channel of the River. In particular, a community of Eurale ferox was found at the backwater wetland of the Daejeo side of the main channel. The introduced species of Eichhornia crassipes and Pistia stratiotes that were epidemic in 2001 at West Nakdong River was not found any more. The other species such as Nymphoides indica, Myriophyllum spicatum, Ruppia spp. were rediscovered. The large area (about 1,300ha) of Zostera spp. was the main sources of food for swans, but disappeared because of direct and indirect impacts of reclamation in the River estuary. Currently, there remains a small patch of Zostera spp. and about 250ha of S. triqueter. Schenoplectus triqueter grew mostly between April-September and tuber formed, between September-October. The growth of S. triqueter up to $60\sim80cm$ in length was observed in 5 sites out of the 7 sites in brackish area. Tubers of S. triqueter were eaten by waterfowls such as swans as winter food. In five sites, tubers took $44\sim57%$ of total biomass in October. Tubers were found in deep layers; $5\sim15cm$ (9%), $15\sim25cm$ (28%), $25\sim40cm$ (55%), below 40cm $(6\sim7%)$. The distribution of vascular hydrophytes has remarkably changed in the Nakdong River Estuary due to the reclamation of the area. In order to determine the extent of changes of the distribution of these plants and the carrying capacity of the area for waterfowl, an intensive research is urgently needed.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.305-313
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• 2002

The physico-chemical characteristics of water and sediment, and structures of vegetation of the vascular hydrophytes were investigated in the West Nakdong River. Water quality was eutrophic according to the mean values and the ranges of water properties such as pH, DO, BOD, chlorophyll a, total nitrogen and phosphate, and other nutrients. A few cases were hypereutrophic for chlorophyll a level in summer. Soil reaction was weak acid. Composition of sediment was mainly sand except in SI(Sinan chideung) of which was mainly clay, and SU(Suan chideung) of which was mainly silt. Flora of vascular hydrophyte had 26 species and 1 variety comprising 16 families. Trapa japonica was dominant species in the sites of DU(Dunchido), GA(Garak chideung) and SU. Nymphoides peltata and Hydrocharis dubia dominated in DA and SI, respectively. Species diversity and evenness were relatively high in SI and SU but dominance was high in DA. After June, water lettuce(Pistia stratiotes) and water hyacinth(Eichhornia crassipes) were flowed from tributary to the river. Standing crop of macrohydrophytes was high in DA from April to August, but it showed maximum standing crop (445g·dw/㎡) in DU after disturbance by explosive growth of exotic plants in October. In comparison with those in 1985, total productivities in DU and GA decreased to 33.5%, and the reduction ratio of dominant species, Trapa japonica was 56.7%. Najas marina, N. minor, Myriophyllum spicatum and Nymphoides indica have disappeared ever since the Nakdong barrage was constructed in the Nakdong river. They were divided into three groups (GA-SU-DU, DA, SI) by cluster analysis. Introduction of the exotic species in this river caused decreasing of endemic plants including endangered species Euryale ferox and rare species Hydocharis dubia, and food plants for waterfowl such as Trapa japonica, Vallisneria asiatica and Potamogeton crispus.

• Korean Journal of Plant Taxonomy
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• v.37 no.2
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• pp.109-113
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• 2007

Six taxa described by Miki were lectotypified using the specimens deposited in OSA; Myriophyllum oguraense, Najas oguraensis, Najas tenuicaulis, Ruppia truncatifolia, Utricularia minor var. multispinosa and U. tenuicaulis.

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.140.2-140
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• 2003

No Abstract, See Full Text