• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.308-319
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• 2016

The purpose of this study is to identify distribution patterns of hydrophytes in the Mokpo wetland in relation to the depth of water. Sample surveys were conducted based on plant species distribution status and water depths at 274 spots. This study also developed a detailed depth distribution map for Mokpo wetland, which was never done in any previous studies. Through this study, it was found that the average depth of the wetland was 77cm (${\pm}29cm$) and the maximal depth was 157cm. The outer edge was no deeper than 60cm and the center approximately 120~130cm in depth, forming a concave bowl-like shape. This research confirmed inhabitation of 6 types of submerged plants (Verticillate hydrilla, Vallisneria natans, Najas graminea, Potamogeton cripus, Ceratophyllum demersum, and Potamogeton brechtoldi), and three types of floating leaved plants (Euryale ferox, Hydrocharis dubia and Trapa japonica) in the surveyed areas of the wetland. The distribution of these hydrophytes showed a statistically significant difference (${\chi}^2=982.2$, df = 8, p < 0.01), which confirms the fact that distribution varies based on environmental conditions. The most frequently observed species was Trapa japonicas at 244 times, and it showed a distribution pattern by which coverage increased with greater depth, as was also seen in the case of Potamogeton cripus. Five species-Euryale ferox, Hydrocharis dubid, Verticillate hydrilla, Najas graminea, and Ceratophyllum demersum-showed a negative correlation to depth, by which coverage decreased with increasing depth. It has been shown that fundamentally, the distribution of hydrophytes based on depth is affected by ecological factors, but also reflects the environmental properties of Mokpo wetland.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.96-102
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• 1985

A study on the competition-ecological classification of the 10 prominent paddy weed species around bulrush (Scirpus juneoides) to simplify the weed problem concept for the rice production. A serial assessments on the competition ability in space and dry matter production(nutrient depletion) of respective weed species and paddy rice, and the data were used to compute the phenotypic similarity by Single Link Clustering method. Both growth response of weed species in mono- and under the paddy rice standing was very similar (r = 0.969), but the reduction rate as affected by paddy rice standing was negatively correlated with the ability in space-competition(r=-0.513). Dendrogram of 10 weed species based on the phenotypic similarity computed in 4 characters in mono- and under the paddy rice standing was also similar, as Echinochloa c., Ludwigia p., Cyperus s., and Scirpus m. in I-group, Eleocharis k., Scirpus j, in II-group, and Juncus e., Potamogeton d. in III-group, respectively. Also, that of paddy rice to 10 weed species showed Fimbristylis m., Scirpus j., Eleocharis k., Scirpus m., Juncus e. in I-group, and Ludwigia p., Potamogeton d., Monochoria v. in II-group, respectively. The integrated dendrogram by the above two data indicate the I-group with Fimbristylis m., Scirpus j., Eleocharis k. and Juncus e., as higher growth response with relatively lower competition ability to paddy rice, II-group with Cyperus s., Echinochloa c., Potamogeton d., and Ludwigia p., as higher both in growth and competition, and the last, III-group with Monochoria v., and Scirpus m., as lower growth but higher competition, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.310-318
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• 1983

Four methods of vegetation analysis were compared to determine the most suitable method to use in transplanted rice. The highest number of weed species, 14 was obtained with the list quadrat method while the least number, 8 was obtained with the line intercept method. The clip quadrat method tended to overestimate weed species with a low moisture content such as Sagittaria trifolia L. and Ludwigia prostrata Roxb while for the list quadrat method, weed species with a high moisture content such as Sagittaria pygmaea Miq. and Monochoria vaginalis (Burm. f) Pres 1 were overestimated. With the line intercept method, weed species having conspicuous leaf blades such as S. trifolia and Potamogeton distinctus Benn. were dominant. Of the methods tested, the line intercept method was the least desirable because it accounted for the least number of weed species. Any of the others could be use for vegetation analysis without any significant problems arising. However, preference was given to the point quadrat method because of the ease of measurement. It was also less tedious and less time consuming than the other methods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.61-69
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• 1977

The affect of perennial weeds to rice yield and rice growing was evaluated. Rice heading date was shortened 1-4days and rice culm length was shortened 5-10cm in heavy weed growing condition. The ratio of yield reduction were about 50% in Cyperus serotinus, about 57 in Potamogeton distinctus in both rice varieties and about 60% of Eleocharis kuroguwal in heavy perennial growing condition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.258-268
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• 1976

This study was conducted in order to know the ecology and to establish the control method of Potamogeton distinctus A. BENN. The tubers of Bog pond weed was almostly located at soil depth of 10 cm to 20cm, germination rates and number of formed tubers were different according to transplanting depth of soil. Effects of herbicides application on weeds were different according to leaf-stage of pondweed, and the pondweed were withered to death by absorption of Avirosan into the leaves. It was suitable to keep water depth at 3cm level until about a week after Avirosan application.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.1
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• pp.37-51
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• 2015

Sparganium japonicum Rothert. is designated as a near threatened species by the National Institute of Biological Resources and is restrictively distributed in South Korea. To conserve and restore habitats of this plant, we investigated environmental characteristics and vegetation at five habitats during the growing season. Thirty plant species from seventeen families were found in the S. japonicum community. The species frequently found in this community included Utricularia vulgaris, Potamogeton distinctus, Phragmites japonica, Cicuta virosa, Persicaria thunbergii, Phragmites communis, Hydrilla verticillata. Maximum height of this plant reached at August and average height at five habitats is 120 cm at this time. Water and soil environmental factors showed low values compared with that of other wetlands. S. japonicum lived in not only shallow water level but also deep water level. These results can be helpful for S. japonicum habitat conservation and restoration.

• Journal of Plant Biology
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• v.26 no.4
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• pp.197-206
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• 1983

Flora and distribution of vascular hygro- and hydrophytes were investigated from April to June, 1983 on the seven sampling sites along the estuary of Nagdong River. As the result, total 60 kinds of vascular plants are investigated, among them 13 kinds are aquatics; Rotala indica var. uliginosa, Myriophyllum spicatum, Allisma canalicultum, Vallisneria asiatica, Hydrilla verticillata, Potamogeton berchtoldii, P. crispus, Ruppia maritima, Phyllospadix iwatensis, Zostera marina, Juncus effusus, Phragmites communis, and Scirpus triqueter. Present hydrophytes are largely confined to the main-stream zone. The transition zone is poorly habitated by hydrophytes and considered for the distributconfined to the estuary and coastal zone. However, long-term conditions of salinity gradient appear to be primarily responsible for the present flora and distribution.

• Korean Journal of Plant Resources
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• v.21 no.2
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• pp.162-170
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• 2008

The purpose of this study was to suggest the raw data on establishing the domestic wetland conservation plan. The results of this study were as follows. The vascular plants were summarized as 201 taxa in Ahnshim wetland; 57 families, 154 genera, 179 species and 22 varieties. The rare and endangered plant designated by Korea Forest Service was Hydorcharis dubia. In the wetland plants, the emerged plants were showed Typha angustata, Beckmannia syzigachne, Zizania latifolia, Phragmites communis, Persicaria thunbergii, Oenanthe javanica and Veronica undulata, and the submerged plants were Potamogeton crispus, Vallisneria asiatica, Hydrilla verticillata, Ceratophyllum demersum and Myriophyllum verticillatum. And the floating leaved plants were confirmed Potamogeton distinctus, Hydrocharis dubia, Nelumbo nucifera and Nymphoides peltata, and the floating plants were Salvinia natans, Spirodela polyrhiza and Lemna paucicostata. The naturalized plants were 33 taxa; Avena fatua, Dactylis glomerata, Rumex crispus, Rumex conglomeratus, Amaranthus retroflexus, Lepidium apetalum, Tlaspi arvense, Descurainia pinnata, Potentilla supina, Vicia villosa, Robinia pseruo-acacia, Amorpha fruticosa, Trifolium repens, Medicago sativa, Ailanthus altissima, Euphorbia supina, Oenothera lamarckiana, Quamoclit angulata, Ipomoea purpurea, Solanum nigrum, Veronica perisca, Helianthus tuberosus, Ambrosia artemisifolia var. elatior, Xanthium strumarium, Erigeron annuus, Erigeron canadensis, Conyza sumatrensis, Senecio vulgaris, Bidens frondosa, Tagetes minuta, Taraxacum officinale, Taraxacum laevigatum and Sonchus oleraceus.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.34-40
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• 2004

This study was conducted to get some vegetation information and to find out a way to conseue the ecosystem in the Dongjin River. The riparian vegetation was investigated by Zurich-Montpellier school's method from June 2001 to March 2002. The number of riparian plants were 73 families, 188 genera, 238 species, 33 varieties or 272 Taxa in Dongjin River. The characteristics of life farm spectra were 97 therophytes (35.7%), 78 hydrophytes (28.7%), 41 hemicryptophytes (15.1%) 22 geophytes (8.1%), and 12 chamaephytes (4.4%). The riparian vegetation was identified 8 plant communities (Potamogeton brechtoldii, Hydrilla verticillata, Ceratophyllum demersum, Potamogeton malaianus, Phragmites japonica, Persicaria thunbergii, Cardamine scutata, Persicaria hydropiper) in upstream, 4 plant communities (Zizania latifoliar, Phragmites communis, Persicaria thunbergii, Humulus japonicus) in midstream and 8 plant communities (Hydrocharis dubia, Ceratophyllum demersum, Trapa japonica, Zizania latifolia, Paspalum distichum, Phragmites communis, Pericaria thunbergii, Amphicarpaea edgeworthii) in downstream of the Dongjin River.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.1
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• pp.107-118
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• 1979

The critical low temperature of death under submerged soil was -5^\circ C for the underground tuber of Cyperus serotinus while the vegetative organ (tuber or bulb) of Sagittaria pygmaea and Potamogeton distinctus -6^\circ C, -7^\circ C respectively. On the critical high temperature of death in water bath with 45^\circ C. Potamogeton distinctus and Sagittaria pygmaea were 1 hour, 24 hours, but Cyperus serotinus did not die. When vegetative organs of perenivial weeds setted on the soil surface, the propagation organ of Potamegeton distinctus did not die by desication in 17% of soil moisture, but Cyperus serotinus and Sagittaria pygmaea were dead within 2 to 3 hours in 25^\circ C of soil moisture.