• Asian Journal of Turfgrass Science
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• v.10 no.1
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• pp.71-80
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• 1996

Fourteen dictyostelids(12 species of genus Dictyostelium. 2 species of genus Polysphonylium) oc-curred in Mt. Chiri Korea. Soils samples were collected from the nine sites. In the broadleaved-deciduous forests and conifers, common species of cellular slime molds are Dictyostelium mucoroides, and D. brefeldianum. Only two species are above 30 in importance value and above 50% in presence. Dominant species in the broadleaved-deciduous forests is D. mecoroides wheras in the conifer forests is D. brefeldianum which was not common until now in Korea, found in the low elevation either. In addition, Five cellular slime molds occured in the Miscanthus sinensis community: 4 species of genus Dictyostelium and 1 species of genus Polysphonylium. Dominant species is D. purpureum. Importance value is very high, 85. This Result is exceptively unusual. It dind't occur in the other sites. Correlation between the altitudes and the occurrence and distribution of dictyostelids was not accurate. Merely dominant species were different according to forest types and organic matter contents in soil. Cellular slime molds have different favorite forest types. And the growth and germination are dependent on the soil enviroryrnental conditions and soil quility. Key words:Dictyostelids, Mt. Chiri D. mecoroides, D. brefeldianum. D. purpureum. Soil quility, Favorite forest type, Soil environmental condition.

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.113-122
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• 2014

This study was conducted to clarify the community characteristics of wintering waterbirds in Geum River from September, 2011 to March, 2012 (1st) and from September, 2012 to March, 2013 (2nd). 63 species of waterbirds including raptors were observed during the survey. 50 species of 188,673 individuals recorded during the first survey, and 56 species of 116,611 individuals were recorded during the second survey. The dominant species was high dominance dabbling ducks by Baikal Teals, Mallards, Spot-billed Ducks, Greater White-fronted Geese, Black-tailed Gulls and Common Shelducks. We classified the wintering waterbirds into 9 taxa based on the similar ecological characteristics and analyzed the correlation with temperature. As a result, dabbling ducks, diving ducks and raptors showed positive correlation and herons and waders showed negative correlation. Geese, swans and dabbling ducks were high habitat utilization ratio at the Geumgang estuary barrage upstream area, and diving ducks, herons, waders and gulls were high habitat utilization ratio at the Geumgang estuary barrage downstream area.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.219-230
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• 2012

We surveyed 23 sites of Jinhae Bay in spring and summer 2010 in order to study the correlation between the variation of environmental factors, including salinity, temperature, and nutrients and the characteristics of phytoplankton community structures in summer stratification. Phytoplankton biomass was high in the surface water in summer; however, it was very low in the bottom water. The results showed a negative correlation between chlorophyll a (chl. a) and nutrients (silicate, nitrate, nitrite, ammonium, and phosphate) or nutrients ratio in summer; however, there was mostly a positive correlation between chl. a and these nutrients in spring. This inconsistent correlation between spring and summer was attributed to the phytoplankton community, because a diverse phytoplankton community has different nutrient uptake abilities. In addition, the results of CCA (canonical correspondence analysis) showed a negative correlation between phosphate and dominant species, including Chaetoceros spp., Skeletonema costatum-like spp., and Pseudo-nitzschia delicatissima in summer, but a strong positive correlation between DIN (dissolved inorganic nitrogen) and the dominant species, including Cryptomonas spp. and Pseudo-nitzschia multistriata in spring. Consistently, the dominant algal species in summer showed a relatively smaller size cells compared with those in spring, suggested that it may have related with the low nutrient levels at surface layer due to strong stratified water column of summer.

• Korean journal of applied entomology
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• v.49 no.3
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• pp.175-185
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• 2010

The effect of altitude and latitude on biodiversity (or species richness) has been a topic of great interest for many biogeographers for a long time. This study was conducted to examine the dynamics of species richness of aquatic insects along the altitudinal gradient in 24 wetlands on Mt. Halla, Jeju and test the Rapoport's rule. The species richness of aquatic insects monotonically decreased with increasing altitude, showing a significant inverse correlation (r = -0.64). However, the pattern of species richness with altitude showed a hump-shaped relationship, with a peak in species richness at intermediate elevations when the effects of area were removed. The altitudinal range of species tended to increase with increasing altitude, as Rapoport's rule predicts. There was a positive correlation between the altitudinal range size and the midpoint of the range size (Median) except for Hemiptera (Odonata: r = 0.75, Hemiptera: r = -0.22, Coleoptera: r = 0.72, Total: r = 0.55). Also, the extent of average altitudinal range of high-altitude species was 904.3m, and it was significantly wider than a 469.5m of low-altitude species. Consequently, the species richness of aquatic insects in wetlands on Mt. Halla along the altitudinal gradient well supported Rapoport's rule.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.100-115
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• 2014

For this study, we collected fishes of seven times at the 51 sites by stream orders (2-6) from November 2007 to September 2010. In the results, 55 species belonging 12 families were collected. And there were one species (1.8%) of Natural monument, 6 species (10.9%) of endangered and 22 species (40.0%) of Korea endemic. Dominant species was Zacco koreanus and subdominant species was Zacco platypus in whole. Stream orders (2-6) increased with increasing species, diversity (H'), evenness (EI), richness (RI), tolerant (TS), omnivore (OS) and decreasing individual, dominance (DI), sensitive (SS) insectivore (IS), total IBI score. Principal component analysis results showed location of variable (species, individual, community index, relative abundance of tolerant, sensitive, omnivore, insectivore species) and each site changes in upstream and down-stream changes in their distribution. Correlation analysis showed significant differences between stream orders (2-6) and variable (species: Sp, diversity index: H', omnivore species: OS, stream depth: SD, stream width: SW and water temperature: WT).

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.684-693
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• 2017

The purpose of this study was to analyze fish communities in the Wonju stream located in Wonju-si in Gangwon-do, and to evaluate the health of the stream through past and present changes. We performed investigations four times from May 2015 to September 2016. In the survey, 5,201 individuals which belonged to 27 species and 9 families were collected. Zacco platypus was the dominant species and Pungtungia herziwas the subdominant species. Eight Korean endemic species (Acanthorhodeus gracilis, Zacco koreanus, Coreoleuciscus splendidus, Squalidus gracilis majimae, Microphysogobio yaluensis, Iksookimia koreensis, Koreocobitis rotundicaudata, Coreoperca herzi) were observed and showed a ratio of 16.54%. The fish community of dominance ($0.72{\pm}0.10$), diversity ($1.37{\pm}0.32$), evenness ($0.61{\pm}0.13$), and richness ($1.70{\pm}0.23$) were evaluated. According to our analysis of tolerance guilds, the total individual number of intermediate species was higher than the sensitive and tolerant species. As a result of the trophic guild analysis,the omnivore and insectivore species were relatively high. The value of the qualitative habitat evaluation index (QHEI) in the wonju stream was averaged 121.2 (${\pm}23.4$), indicating a suboptimal condition. Stream health showed that the fish assessment index (FAI) value was an A to C grade in the Wonju stream. A correlation coefficient analysis with FAI and various factors was analysed statistically, and had a high correlation in QHEI, with the omnivore species, insectivore species, intermediate species, sensitive species, dominance, diversity, evenness, and richness.

• The Korean Journal of Ecology
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• v.24 no.5
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• pp.289-296
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• 2001

Community structure of the Salix and physico-chemical properties of sediment were studied from July to September, 2000 in Nam-River watershed for the purpose of inquiring niche breadth, niche overlap and the environmental factors affecting the distribution of Salix species. Among eleven Salix species, the dominant species was Salix koreensis, while the rests were such order as S. nipponica, S. gracilistyla and S. glandulosa by the relative abundance based on the basal area. Mean values and the ranges of sediment properties such as pH, conductivity, water content, organic matter, total nitrogen, available phosphorus, clay, silt and sand were 5.3∼6.3, 14∼351 μmho/cm, 0.1∼3.4%, 0.5∼7.3%, 0.01∼0.2%, 0.1∼0.4 mg/100 g, 1.7∼22.0%, 0.2∼40.8%, 39.7∼98.0%, respectively. Altitude and annual mean temperature of each site were 20∼620 m and 9.3∼13.0℃, respectively. Niche breadth was estimated by considering the differences of the soil texture as the differences of state of source. S. glandulosa was the broadest at the level of 0.77, while the rests were such order as S. koreensis, S. nipponica were 0.69, 0.54, respectively. The niche overlap showing the level of interspecific competition was the largest as 0.94 between S. purpurea var. japonica and S. purpurea var multinervis, while S. graciliglans and S. purpurea var. japonica 0.92, S. graciliglans and S. purpurea var. multinervis 0.87, respectively. According to the analysis of the correlation between eleven species of Salix and eleven environmental factors, S. gracilistyla showed the negative correlation with conductivity, water content, total nitrogen, clay, silt and annual mean temperature, and showed the positive correlation with total nitrogen, sand and altitude. S. graciliglans showed the negative correlation with conductivity, water content, organic matter, clay, silt and annual mean temperature, and showed the positive correlation with total nitrogen, sand and altitude. S. nipponica showed the negative correlation with sand and altitude, and showed the positive correlation with water content, total nitrogen, clay, silt and annual mean temperature. S. nipponica showed the opposite results of S. gracilistyla. Soil texture, total nitrogen, water content, altitude and annual mean temperature were affecting the distribution of Salix species in Nam-River watershed.

• The Korean Journal of Ecology
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• v.13 no.4
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• pp.297-309
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• 1990

The distribution of aquatic macrophytes in TanChon basin, a stream of the Han River, were investigated in terms of environmental gradient from June 1989 to March 1990. In the basin, 12 species of aquatic macrophytes were listed and four communities of Potamogeton crispus community. $P. octandrus$ community, $Hydrilla verticillata$ community and $Vallisneria$ asiatica community were recongized by character species. $P. crispus, P. octandrus$ and $V. asiatica$ were found in rapids while $H. verticillata , Ceratophyllum demersum$ and $Trapa japonica$ were done in pools. The depth of sediment $TanCh\u{o}n$ was showed as a exponential function of water velocity, Bd=exp (-K Wv). The values of Biochemical Oxygen Demand(BOD), Chemical Oxygen Demand(COD) and Suspendid Solid(SS) were recorded as range of 3.2~121.0mg/1, 4.2~54.5mg/1 and 4.1~114.0mg/1, respectively. And the linear positive correlation between BOD(X) and COD(Y) were expressed as Y=3.904+0.4308 X with $R^2$=0.9808 and also the correlation between BOD value(X) and SS value(Y) were done as Y=5.333+0.9606X with $R^2$=0.9700. In two dimensional analysis of BOD and water velocity, their clusters were showed similar types matching to communities classified by character species. However, no aquatic macrophyes were found at the site with BOD$\geq$50mg/l or DO$\leq$0.2mg/l.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.203-208
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• 2003

Losses in the dry weight of leaf litter from six tree species were studied during 16 months on the forest floor in temperate deciduous forest of Mt. Cheonma in the vicinity of Seoul in Korea by using litter bag method. The decomposition rate of each leaf litter varies with each species. After 16 months elapsed, the leaf litter of Acer pseudo-sieboidianum showed the highest decomposition constant (0.82) as Olson´s decomposition constant, while that of Pinus densiflora showed the lowest decomposition constant (0.33). The decomposition constant of Quercus mongolica, Q. serrata, Betula ermani and Carpinus laxiflora showed 0.43, 0.37, 0.66 and 0.75, respectively. The decomposition constant of leaf litter was considered with temperature and precipitation which accumulated daily during each term of litter bag collection. The decomposition constant of leaf litter showed closely positive correlation with daily accumulative temperature and precipitation. The relationships between decomposition constant and the daily accumulative temperature and precipitation at each period of litter bag collection were analyzed through multi-regression analysis. The correlation coefficients as a result of multi-regression analysis in Q. mongolica, Q. serrata, P densiflora, B. ermani, C. laxiflorais and A. pseudo-sieboldianum were 0.83, 0.81, 0.69, 0.77, 0.77 and 0.62, respectively. The precipitation showed higher effect, about 10 times, on the leaf litter decomposition than the daily accumulative temperature.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2079-2091
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• 2024

In this paper, a model is developed for calculating pH in the presence of organic impurities due to dissolution of paint and/or continuous injection of organic impurities in the sump. The model is implemented in the AnCheBi code for the analysis of chemical behaviors of the iodine in the containment when the pH changes during a severe accident. Validation of the model is performed with P10T2 and P11T1 experiments carried out by AECL in Canada under the BIP project. Importance analyses of the pH calculation model in the AnCheBi code are then performed with the aforementioned experimental data via Latin hypercube sampling on the reaction coefficients, sensitivity analyses of AnCheBi, and calculation of the correlation coefficients between the reaction coefficients and figure of merits (the pH and the concentrations of the various iodine species). From the importance analyses, we provide the sensitivity of the pH calculation model to the change of pH and the concentrations of the various iodine species and the reaction coefficients related with the dominant phenomena underlying the change of pH and the concentrations of the species.