• Korean Journal of Weed Science
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• v.5 no.2
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• pp.175-186
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• 1985

Research situation and recent research activities of the RDA of Korea were reviewed and summarized for rice nurserybed. Sixty five percent of total 784 weed research items were carried out as rice research while only 6 percent was belonged to nurserybed within rice research. The floristic composition based on the degree of dominance significantly affected by herbicide properties, type of nurserybed and seeding itself. Herbicidal phytotoxicity of currently used several herbicides was greatly dependent upon the covering, absorption, germination, and irrigation regimes. The new safening agent "CGA 123 407" (4,6-dichloro-2-phenyl-pyrimidine) permited the safe application of pretilachlor (2-chloro-2',6-diethyl-N-(2-propoxyethyl) acetanilide) as a pre-emergence herbicide without reducing herbicidal efficacy. Several new herbicides, pyrazolate (4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yl-p-toluenesulphonate), SL-49 (1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-phenacyloxy-pyrazole) MY-93 (S(1-methyl-1-phenethyl)-piperidine-1-carbathioate) and DPX-84 ((methyl 2- ((4,6-dimethoxypyrimidin-2-yl) amino-carbonyl) aminosulfonylmethyl)) benzolate)) performed satisfactorily in terms of safety and herbicidal efficacy for both surface covered and surface pressed nurserybed after herbicide application and thus expected very significant contributions not only for all kind of nurserybeds but also for direct seeding.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.727-743
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• 1996

To know the floristic composition, vortical distribution and community structure of marine benthic algae inhabiting in the intertidal and subtidal zones of Yongil Bay, east coast of Korea, the study has performed using the quadrat method along a transect line from July, 1995 to June, 1996. In this area, a total of 144 species including 2 new red algae to Korea was found: 5 blue-green, 18 green, 20 brown and 101 red algae. The representative species throughout the year were Ulva pertusa, Gelidium amansii and Symphyocladia latiuscula. Dominant species were Sargassum thunbergii in spring, U. pertusa in summer and autumn. In winter, Chondrus ocellatus and Monostroma grevillei occurred dominantly. The standing crop exhibited mean value as $185.8g/m^2$ dry weight. Maximum value was recorded in spring $(267.3g/m^2)$ and minimum was observed in winter $(93.7g/m^2)$. Shannon's species diversity (H') and evenness (J') as maximum value were recorded in spring, whereas minimum values were shown in winter. Vertical distribution, rerognized by cluster analysis based on relative coverage of the species, could be divided into two or three algal groups except spring. In general, green algae (M. grevillei, Capsosiphon fulvescens, U. pefusa, Enteromorpha compressa) and brown algae (Sargassum fulvellum, S. thunbergii) were represented in the upper and middle zone and red algae (G. amansii, C. ocellatus, S. latiuscula, Crateloupia okamurae, Pachymeniopsis eilliptica) in the lower zone. The algal community varied according to season and environmental conditions. Particularly, seasonal variation of vortical distribution seemed to be affected primarily by water temperature. Also seasonal tidal level and tolerance of algal species to desiccation appeared to be associated with it in this area.

• Journal of Wetlands Research
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• v.7 no.4
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• pp.67-80
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• 2005

Vegetation structure of the vascular plants was investigated from April 2003 to August 2003 in Hwangjeong wetland around Geumho River, Yeongcheon-si, Gyeongsangbuk-do, Korea. Actual vegetation of Hwangjeong wetland largely can be classified by the floristic composition and the physiognomy into 12 communities; Ambrosia artemisiifolia var. elatior, Humulus japonicus, Miscanthus sacchariflorus, Phragmites japonica, Zizania latifolia-Miscanthus sacchariflorus, Zizania latifolia-Nymphoides peltata, Miscanthus sacchariflorus-Phragmites japonica, Phragmites communis-Phragmites japonica, Phragmites japonica-Salix gracilistyla, Salix koreensis-Salix glandulosa, Salix nipponica-Salix koreensis, and Phragmites japonica-Zizania latifolia. Among them, the distribution area of the Phragmites japonica community was the largest as 49.46 ha(11.03%). The dominant vegetation type was Phragmites japonica community and Ambrosia artemisiifolia var. elatior community based on the phytosociological method, and Phragmites japonica community was classified into two subcommunities; Nymphoides peltata subcommunity and Salix glandulosa subcommunity. Differential species of Phragmites japonica community were Phragmites japonica, Miscanthus sacchariflorus, Persicaria thunbergii, Oenanthe javanica, Leersia oryzoides var. japonica, and Rorippa indica; differential species of Ambrosia artemisiifolia var. elatior community were Ambrosia artemisiifolia var. elatior, Setaria glauca, Commelina communis, Cyperus orthostachyus, Digitaria sanguinalis, Xanthium strumarium, Erigeron annuus, Erigeron canadensis, Kummerowia striata, Trifolium repens, and Medicago sativa; differential species of Nymphoides peltata subcommunity were Nymphoides peltata, Zizania latifolia, Scirpus tabernaemontani, and Eleocharis mamillata var. cyclocarpa; differential species of Salix glandulosa subcommunity were Salix glandulosa, Salix koreensis, and Salix gracilistyla. It was expected that Hwangjeong wetland is worthy of conservation contributed purifying water pollution, giving habitats of many lifes, and providing beautiful scenes of Geumho River.

• Korean Journal of Environmental Biology
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• v.17 no.1
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• pp.35-50
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• 1999

The relationship between floristic composition and soil environmental conditions was investigated in the forest vegetation of Mt. Paekun. The forest vegetation unit of Mt. Paekun was divided into six plant communities by Zurich-Montpellier method, such as Quercus mongelica community (Typical subcommunity, Rhododendron schlippenbaohii subcommunity), Q. variabilis community, Fraxinus rhynchophylla community, Pinus densiflora community, Larix Eeptolepis community and Pinus koraiensis community. Q. mongolica community group was distributed at the altitude over 500 meter, Q. variabilis and P. densiflora communities appeared on the southwestern slope at the altitudes of 600 ~ 700 m and 290 ~ 700 m. However, L. leptolepis and P. koraiensis plantation were distributed at lower altitude, on hillside or around homestead. The DBH class distribution of dominant species in each community showed that Q. mongolica had 10.9 individuals/a at 6~10 cm class, Q. variabilis 2.5 individuals/a at 11~15 cm class, P. densiflora 1.8 individuals/a at 26~30 cm class, F. rhynchophylla 3.3 individuals/a at 2~5 cm class, and L. leptolepis 5.9 individuals/a at 11~ 15 cm class. Q. mongolica and Q. variabilis communities showed a stable bell-shaped pattern of distribution. The contents of organic matters and soil water, and cation exchange capacity of the soil increased, and the pH decreased as the altitude gets higher increased altitude at the each communities. The contents of the soil water and organic matters of the forest soil collected in Q. mongolica community were in the 17.81% to 51.20% and 5.51% to 14.90%, respectively. These tendency is similar to the contents of N, P and K, but those of Ca, Mg, and CEC was lower than in other communities. Cation exchange capacity was suspected to be correlated to the pH. The hypothetical successional sere of the forest vegetation of Mt. Paekun is as follows: Pinus densiflora community longrightarrowQ. variabilis community longrightarrowQ. mongolica community.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.223-245
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• 1983

Nationwide weed survey of paddy rice field conducted in 1981 and 1971 was compared and determined major dominant weed community types distributed by province. Based on the similarity coefficients between 1971 and 1981 the floristic composition based on the degree of dominance was greatly dissimilar while kind of weed flora were not much differed. Degree of dominance were concentrated to perennial weeds in 1981 while these were at animal weeds in 1971. The moat important 10 weed species and their dominance in 1981 were Monochoria vaginalis Presl.(22.2%), Sagittaria pygmaea Miquel(17.5%), S. trifolia L.(9.0%), Poramogeton distinctus Benn.(9.0%), Cyperus serotinus Rottb.(8.5%), Rotala indica Koehne(6.0%), Aneilema japonica Kunth(4.4%), Lindernia procumbens Philcox(3.9%), Eleocharis kuroguwai Ohwi(3.4%) and Ludwigia proarrara Roxb(3.0%), respectively while these for 1971 were R. indica(34.5%), Eleocharia acicularis Roem, et Schult (11.9%), M. vaginalis(11.1%), Cyperua difformis L.(8.7%), Echinochloa crus-galli Beauv.(6.9%), L. procumbens(3.3%), P. distinctus(3.1%), A. Japonica (2.4%), E. kuroguwai(1.8%) and P. hydropiper(1.8%), respectively. Weed occurrence was also closely related with soil type, cropping pattern and cultural practices. Particularly, the occurrence of P. distincrus was negatively correlated with the degree of land utilization. Weed community types dafined by two-dimensional ordination analysis were 11 for Jeonnam province, 9 for Gyeoaggi, Gangweon, Chungbuk and Gyeongnam provinces, 8 for Jeonbuk and Gyeongbuk provinces, 7 for Chungnam province and 4 for Jeju province, respectively.

• Journal of Wetlands Research
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• v.7 no.3
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• pp.87-95
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• 2005

Vegetation structure of the vascular plants was investigated from March 2003 to October 2003 in Haepyeong wetland, Gumi-si, Gyeongsangbuk-do, Korea. Actual vegetation of Haepyeong wetland largely can be classified by floristic composition and physiognomy into 18 communities; Xanthium strumarium-Digitaria sanguinalis, Humulus japonicus, Persicaria perfoliata-Humulus japonicus, Phragmites japonica-Miscanthus sacchariflorus, Persicaria hydropiper-Phragmites communis, Persicaria hydropiper, Phragmites japonica-Persicaria hydropiper, Miscanthus sacchariflorus- Phragmites japonica, Persicaria hydropiper-Phragmites japonica, Miscanthus sacchariflorus-Salix glandulosa, Salix nipponica-Salix glandulosa, Salix nipponica-Salix koreensis, Salix nipponica, Miscanthus sacchariflorus-Salix nipponica, Phalaris arundinacea-Salix nipponica, Salix glandulosa-Salix nipponica, Trapa japonica, and Ceratophyllum demersum-Trapa japonica. Among them, the area of the Salix nipponica-Salix koreensis community was the largest as 122.2ha(9.23%). The dominant vegetation type was Miscanthus sacchariflorus-Persicaria hydropiper community based on phytosociological method, and it was was classified into three subcommunities; Salix glandulosa-Salix nipponica subcommunity, Digitaria sanguinalis subcommunity, and Cyperus amuricus subcommunity. Differential species of Salix glandulosa-Salix nipponica subcommunity were Salix nipponica, S. glandulosa, S. koreensis, Scirpus radicans, Persicaria maackiana, and Achyranthes japonica; differential species of Digitaria sanguinalis subcommunity were D. sanguinalis, Setaria viridis, Ambrosia artemisiifolia var. elatior, and Cyperus orthostachyus; differential species of Xanthium strumarium subcommunity were X. strumarium, Acalypha australis, Erigeron canadensis, Echinochloa crus-galli, and Vicia tetrasperma. Zonation of vascular hydrophytes and hygrophytes was as followers: Salix glandulosa, S. koreensis, S. nipponica were distributed in the region of land which water table is low, and Persicaria maackiana, Persicaria hydropiper, Scirpus radicans were distributed in the understory. And emergent plants such as Phragmites communis and Scirpus karuizawensis, floating-leaved plant such as Trapa japonica, submersed plant such as Ceratophyllum demersum, and free floating plant such as Spirodela polyrhiza formed the zonation from shoreline to water. The specified wild plants designated by the Korean Association for Conservation of Nature, Ministry of Forest, and Ministry of Environment were not distributed in the study area. It was expected that Haepyeong Wetland worthy of conservation contributed purifying water pollution, giving habitats of many lifes, and providing beautiful scenes of the river.

• Korean Journal of Plant Resources
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• v.12 no.3
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• pp.240-252
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• 1999

Floristic composition and phytosociological studies of Mt. Chongok and Mt. Tuta were investigated, and that was compared with the previously published report in 1993. Vascular plants were composed of 100 families, 358 genera, 573 species, 95 varieties, and 18 formae, totaling 686 taxa. The vegetation was relatively well conserved based on Pteridophyta calculation (Pte-Q), 1.13. Compared with the vascular plants of the southern and northern slope area, the vascular plants of the southern slope area were composed of 87 families, 287 genera, 419 species, 73 varieties, and 11 formae, totaling 503 taxa, and those of the northern slope area consisted of 94 families, 293 genera, 427 species, 73 varieties, and 12 formae, totaling 512 taxa, respectively. Also, compared with the taxa in each side, both sides were composed of 332 species in common, southern sides, 172 species and northern sides, 182 species, respectively. The number of species of 11 families belonged to the higher level among total families taxa was composed of 328 species(47.8%). Among them, Compositae and Rosaceae were included much more species than remnant families. Korean endemic species were composed 16 families, 24 genera, 20 species, 8 varieties and 2 formae, totaling 30 species(4.4%). Compared with the Korean endemic taxa in each side, both sides were composed of 14 species in common, southern sides, 11 species and northern sides, 5 species, respectively. A naturalized plants were 20 species, correspond to 9.2% of totaling 218 species appeared in South Korea. Among them,12 species were appeared commonly in both sides, southern sides, 16 species and northern sides, 16 species, respectively. Life form spectra was H-D1-R5-e type and, useful resources plants are as follows; edible source(42.4%), medicinal source(31.5%), ornamental source(15.6%) and pasture source (13.3%) in the total region. The forest vegetation of the southern slope was classified into 1 order, 1 alliances and 5 communities; Rhododendro-Quercetalia mongolicae, Lindero-Quercion mongolicae, Quercus mongolica Typical community, Populus davidiana-Quercus mongolica community, Pinus koraiensis-Taxus cuspidata community, Pinus densiflora-Carex humilis var. nana community, Betula costata-Betula ermanii community. It is considered that the slight difference of the flora and vegetation in the northern and southern slope is mostly due to the topographical and climatic difference. Even closer investigation is required for the more accurate comparison in this area.