• Journal of Environmental Science International
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• v.28 no.10
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• pp.899-905
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• 2019

Recently, an innovative method for wastewater treatment and nutrient removal was developed by combining the sequence batch reactor and membrane bioreactor to overcome pollution caused by shipboard sewage. This system is a modified form of the activated sludge process and involves repeated cycles of mixing and aeration. In the present study, the bacterial diversity and dominant microbial community in this wastewater treatment system were studied using the MACROGEN next generation sequencing technique. A high diversity of bacteria was observed in anaerobic and aerobic bioreactors, with approximately 486 species. Microbial diversity and the presence of beneficial species are crucial for an effective biological shipboard wastewater treatment system. The Arcobacter genus was dominant in the anaerobic tank, which mainly contained Arcobacter lanthieri (8.24%), followed by Acinetobacter jahnsonii (5.81%). However, the dominant bacterial species in the aerobic bioreactor were Terrimonas lutea (7.24%) and Rubrivivax gelatinosus (4.95%).

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.3
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• pp.129-136
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• 2001

The alpine grassland vegetation at the northwest slope of Mt. Paektu were investigated by Penound- Howard's cover-degree method. The floristic composition of the alpine grassland from 2,100m altitude to the top of mountain were 35 species, 1 subspecies, and 6 varieties, and most of the plants were short p e r e ~ i a l herbs and shrubs. The dominant species of the vegetation distributed along to altitude were Rhododendron aureum (2,100-2,20Om), Dryas octopetala var. asiatica(2,200-2,30Om), Dryas octopetala var. asiatica(2,300-2,40Om), Rhododendron aureum- Rhododendron redowskianum(2,400-2,50Om), and Rhododendron redowskianum(2,500- 2,58Om), respectively. Characteristics of the shrub plants which settled in alpine grassland showed uniform low height(3-15cm), creeping stem and evergreen leaf. Life form of the plants were 29 species of Hemicryptophyte, 8 species of Chamaephyte, 1 species of Geophyte, and 5 species of Phanerophyte. (Key words : Alpine grassland, Mt. Paektu, Altitude, Dominant, Life form)

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.3
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• pp.341-353
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• 2010

Authors investigated the species composition of fishes for about 13months in the boundary sea water between Busan and Tsushima. We caught 81 species, 1,603 individuals and 437.7kg in biomass. The first dominant species by seasons were common squid, angler, angler and Psenopsis anomala respectively. Angler was also the first dominant species in biomass for four seasons. Catch per unit effort (kg/hr) was the highest in winter and the lowest in summer. But there was a little difference in accordance with station compared with season. There was big difference by season in the diversity index, the evenness index and the dominant index. But there was little difference between above indexes. The total length of common squid was the tallest in autumn and winter, that of blackthroat seaperch was the tallest in autumn and the lowest in winter. But angler's total length was almost same all through the year.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.2
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• pp.58-68
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• 1999

This study was carried out to verify the distribution patterns of Salix gracilistyla and Phragmites japonica communities known as obligatory riparian species according to physical factors such as micro-landforms, substrates, etc., at Soo-ip stream corridor. Firstly four vegetation types - Salix gracilistyla dominant type, Phragmites japonica dominant type, mixed type of two species, and mixed type of two species to other species, were classified by cluster analysis based on UPGMA-Euclidean distance. Also these vegetation types showed many different distribution patterns in response to the longitudinal and lateral view along the stream corridor and substrate composition. Salix gracilistyla was major component of dominant vegetation types developed at attack point of bending reach and on substrates composed of rock fragments, but contrastly Phragmites japonica was most important component of dominant vegetation types at point bar of bending reach and floodplain, and on substrates composed of soil materials. Secondly the species and environment biplot form CCA strongly supported the vegetation types divided by classification. Namely Salix gracilistyla was closely correlated with rock fragments and steep slope, which is resistant to physical action even though located near running water. But Phragmites japonica showed a high correlation with soil particles sedimented at floodplain by divergent flow.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.126-135
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• 2018

Wood decay fungi were collected in 47 different locations in eight provinces of South Korea from 2011 to 2013. One thousand and five hundreds three fruiting bodies of wood-decay fungi were collected, identified, and classified into 2 phyla, 7 classes, 19 orders, 56 families, 159 genera and 365 species. The most dominant genus and species found were Trametes and T. versicolor. The highest species diversity was found in broad-leaved forest (273 species), and was also found at elevations of 500-1,000 m (227 species). A total of 333 species were collected from broad-leaved trees, 87 species from coniferous trees, and 55 species were collected from both forest types. Gymnopilus liquiritiae was the most dominant species in coniferous trees, while T. versicolor, which was mostly collected from tree trunks below 500 m in elevation, was dominant in broad-leaved trees. Results from the quantitative cluster analysis of wood decay fungi showed that the highest species diversity index was 1.80 in the mixed forests, while the highest similarity among forest types was shown between the broad-leaved and mixed forests.

• Asian Journal of Turfgrass Science
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• v.10 no.1
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• pp.81-88
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• 1996

Twelve dictyostelids occurred in the southern coastal area and islands; nine species of genus Dictvostelium and three species of genus Polysphoslylium. In ten sites of evergreen-broadleaved forests, 12 species were identified and average prensent species was 6.0. D. mucoroiles, D. misutum, P. pallilum and P. violaceum were dominant species. The first dominant species was D. mucoroides. Its importance value was 55 and was much more than the others. Especially, for P. violaceum presence was 90%. It was much higher. But relative density was no more than 3%. D. minutum that was not common species had comparahly high im- portance value. In two sites of evergreen conifers, only four species occurred; D. mucoroiles, D. brefeldianum, D. capitatum and P. pallilum Average present species was 2.0. Dominant species was D. mucoroides. Average of total clones in evergreen-hroadleaved forests and evergreen conifers were irrespectively 8,608 and 9,541. As for the number of species, cellular slime molds distributed variably in evergreen-broadleaved forests than evergreen conifers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.498-507
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• 2021

Ichthyoplankton (fish eggs and larvae) were collected seasonally collected from 2017 to 2019 to clarify whether Dokdo serves as a fish spawning and/or nursery ground. Fish eggs were identified and classified into 16 species. The dominant fish egg species were Engraulis japonicus, Maurolicus japonicus, and Parajulis poecilepterus. Fish larvae were identified and classified into 15 species. The dominant fish larvae species were E. japonicus, M. japonicus, and Sebastes owstoni. A cluster analysis similarity percentages revealed two distinct groupings according to sample location (stations) with E. japonicus and M. japonicus as the main group influencers. E. japonicus was the dominant species off Dokdo. The species diversity and abundance peaked in summer. The diversity index, richness index, and evenness index fluctuated seasonally. There were no predominant species variations among the years. Sedentary species such as P. poecilepterus, Semicossyphus reticulatus, and Glyptocephalus stelleri occurred in the inshore stations. E. japonicus, M. japonicus, and Trachipterus trachypterus occurred in the offshore stations. Our results show these species use Dokdo as spawning and nursery grounds.

• Journal of Ecology and Environment
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• v.47 no.1
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• pp.1-13
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• 2023

Background: The positive effects of Arctic plants on the soil environment and plant-species co-occurrence patterns are known to be particularly important in physically harsh environments. Although three dominant plants (Cassiope tetragona, Dryas octopetala, and Silene acaulis) are abundant in the Arctic ecosystem at Ny-Ålesund, Svalbard, few studies have examined their occurrence patterns with other species and their buffering effect on soil-temperature and soil-moisture fluctuation. To quantify the plant-species co-occurrence patterns and their positive effects on soil environments, I surveyed the vegetation cover, analyzed the soil-chemical properties (total carbon, total nitrogen, pH, and soil organic matter) from 101 open plots, and measured the daily soil-temperature and soil-moisture content under three dominant plant patches and bare soil. Results: The Cassiope tetragona and Dryas octopetala communities increased the soil-temperature stability; however, the three dominant plant communities did not significantly affect the soil-moisture stability. Non-metric multidimensional scaling separated the sampling sites into three groups based on the different vegetation compositions. The three dominant plants occurred randomly with other species; however, the vegetation composition of two positive co-occurring species pairs (Oxyria digyna-Cerastium acrticum and Luzula confusa-Salix polaris) was examined. The plant species richness did not significantly differ in the three plant communities. Conclusions: The three plant communities showed distinctive vegetation compositions; however, the three dominant plants were randomly and widely distributed throughout the study sites. Although the facilitative effects of the three Arctic plants on increases in the soil-moisture fluctuation and richness were not quantified, this research enables a deeper understanding of plant co-occurrence patterns in Arctic ecosystems and thereby contributes to predicting the shift in vegetation composition and coexistence in response to climate warming. This research highlights the need to better understand plant-plant interactions within tundra communities.

• Asian Journal of Turfgrass Science
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• v.7 no.2_3
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• pp.113-120
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• 1993

Dictyostelid cellular slime molds were quantitatibly isolated from Korean lawngrass turf in Seoul National University, Korea, by the 'Clonal Isolation Technique(Cavender and Raper, 1965a)'. Total six species were found. These are Dictyostelium sphaerocephalum. D. purpuream. D. flavidam, D. crassica ale, Polysphondilium pallidum. P. violaceum. D. sphaerocephalum was the dominant species and P. violaceum, D. flaviidum, D. crassicaule were rare. Compared with other region, species diversity and species richness of Korean lawngrass turf appeared to he low. The dominant species, however, is not very common in other plant communities, so it cnay he characteristic of Korean lawngrass turf.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.6
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• pp.399-412
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• 2005

This study investigated the composition and the distribution of the benthic polychaeta community in the semi-enclosed Yoja Bay on the southern coast of Korea and was designed to deduce temporal changes in the community with the comparison of the previous studies. In YoJa Bay, benthic polychaetous community structure was investigated on the base of the samples from 87 stations. The surface sediment was mainly composed of fine-grained sediment, mixed clayey silt and silty clay. The total benthic macrofaunal density was $387 indiv./m^2$, and the density was higher in the middle bay, and in the mouth of bay than in the inner bay. scapharca subcrenata (Bivalvia) and amphipods (Crustacea) were important species in the inner and the middle of the bar, respectively. Benthic polychaetes were comprised of 72 species with a mean density of $149 indiv./m^2$. Their distributions showed higher densities in the mouth of bay than in the rest of bay. The dominant species over 1.0 percentages were composed of the 20 species, and they occupied $84.5\%$ of the total density. The most dominant species was Sternaspis scutata ($13.6\%$), fallowed fly Heteromastus filiformis ($9.8\%$), Polynoidae indet. ($8.3\%$), Sigambra tentacuzata ($7.1\%$) and others. The cluster analysis revealed that the study area was divided into three station groups. At the station group YI located in the inner bay, the most dominant species was Heteromastus filiformis . At the station group YII in the middle bay, the dominant species was Sternaspis scutata. And at the station group YIII in the mouth of bay, the dominant species was Paraiacydonia paradoxa. Whereas Sternaspis scutata and Mediomastus sp. were the dominant species in the past study, Heteromastus filiformis and Tharyx sp. appeared newly to be the dominant species, even if their low densities that in the past. These facts mean that Yoja Bay be maintained yet as little polluted area compared to other bays on the coast of Korea, but needed some caution of marine environmental management.