• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.947-956
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• 2013

In this study, WUA (Weighted Usable Area) was calculated to determine ecological flow at the confluence of Nakdong River and Gumho River by using River2D. To calibrate River2D, simulation results of River2D were compared with calibrated HEC-RAS simulation results and the optimum parameters were determined. After parameter calibration, WUA of Zacco platypus and Zacco temmincki which are dominant species in Nakdong River was calculated with changing upstream flowrate. From the result, WUA is changed according to flowrate and growth stage. In the flowrate-WUA/A graph, ecological flow can be determined as $33.3m^3/s{\sim}39.96m^3/s$ in Nakdong River and $3.6m^3/s{\sim}4.32m^3/s$ in Gumho River. After dredging for Four major rivers restoration project, WUA of Zacco platypus and Zacco temmincki were calculated by using the ecological flow. The results show that WUA after dredging are decreased when compared with undredged condition. WUA of Common carp is 2~3 times bigger than WUA of Zacco platypus and Zacco temmincki at the dredged condition in Nakdong River.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.285-293
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• 2016

This study conducted the evaluations of stable channel and physical disturbance improvement for optimal construction of river structures by focusing on Wonju River. A stable slope was analyzed sectionally for stable channel design, and in order to satisfy the stable slope, river structure improvement scenarios were deduced. Accordingly, through physical disturbance improvement evaluation for each scenario, the study extracted the optimal scenario for stable channel design and physical disturbance improvements. The changes in physical habitat were analyzed when river structure improvements were made for stable channel design and physical disturbance improvement. Zacco koreanus, an indicator fish of the soundness of the aquatic ecosystem, was selected as a restoration target species by investigating the community characteristics of fish fauna and river environments in the Wonju River. The habitat suitability was investigated by the PHABSIM model with the habitat suitability index of Zacco koreanus. The results of the prediction evaluation showed a slight decrease in habitat suitability and weighted usable area. However, it was not influenced by the improvements in the river structure. The study suggested river structure arrangement methods that can improve physical soundness and safety of Wonju River, and confirmed that there were no effects to the changes in the physical habitat.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.102-108
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• 2020

This study is to analyze the growth response of the Quercus dentata seedlings to four environmental factors and measure the ecological niche breadth. Environmental factors were light, moisture content, soil texture, and organic matter, treated with four gradients. The more quantity light increased, the heavier the leaves biomass, aboveground biomass, belowground biomass and plant biomass was. In treatment of water content and soil texture, growth response was no difference. The more organic matter increased, the heavier aboveground biomass was, but the remaining trait of plant was no difference. The ecological niche breadth was 0.865 in light, 0.995 in moisture content, 0.994 in soil texture and 0.988 in nutrient. Ecological niche breadth was the widest in the moisture content treatment and the narrowest in the light treatment. This means that the growth of Q. dentata seedlings grows well as the amount of light increases, and is sensitive to light, Thus, it is determined a growth and ecological niche breadth by light factors.

• Korean Journal of Environmental Biology
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• v.26 no.2
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• pp.121-127
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• 2008

As a step toward developing conservation and restoration plans for an endangered species of the Oriental White Stork (Ciconia boyciana), we studied daily foraging behavior and ecology. We released two individuals, male and female, after enclosing study site with a fence and cutting out a part of two or three feathers of primaries. Research was conducted from 16 June to 11 July, 2007 for 25 days at Whawonri, Mewonmyung, Chungbuk province. We investigated diural and daily variation of foraging time budget, diet composition, and habitat selection of the feeding individuals. The storks quadratically invested for foraging time and resting time according to time of day, but no significant variation in the foraging time and resting time appeared daily over 25 days. As a result, the storks mainly used wetland as a foraging site in the center of the study area to that in the edge as well as to other types of habitat. The high usage for wetland in the center did not change over the 25 days while Rice field decreased and Wetland in the edge and Pathway increased. Female invested more time for foraging than male, but the foraging efficiency did not differ between them. We discussed the significance of foraging behavior and habitat selection for management plan.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.267-276
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• 2019

The Gonggeomji Reservoir is a historical irrigation facility built in the 8th century and designated as a wetland protected area by Ministry of Environment, Korea. In order to collect the baseline data necessary for developing a sustainable conservation strategy, we investigated the classification of actual vegetation, the vegetation distribution and the floristic structure of the vegetation in the Gonggeomji Wetland Protection Area. In the whole protection area, a total of 26 plant communities were classified including the wetland, riparian, grassland, forest, farmland, and orchard vegetation. According to the results of detrended correspondence analysis, the structure of wetland vegetation was mainly affected by water depth and human disturbance. In reservoir wetlands, floating vegetation such as Utricularia vulgaris var. japonica, Trapa japonica, and emergent vegetation such as Nelumbo nucifera, Typha spp. completely covered the water surface. Since 2014, the reservoir wetland has been terrestrialized with the expansion of emergent and hygrophytic plants. For the sustainable conservation and restoration of wetland protected areas, it is necessary to naturalize the topography and wetland vegetation, recovery the hydrologic system, and restore ecosystem connectivity from wetlands to forests.

• Journal of Life Science
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• v.23 no.1
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• pp.95-101
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• 2013

In this study, plant samples of five species were collected from the Dokdo islands in South Korea. Plant samples such as Asparagus schoberioides, Corydalis platycarpa, Festuca rubra, Sedum oryzifolium, and Setaria viridis were collected from the Dongdo and Seodo. Endophytic fungal strains were isolated from the roots of five plants from the Dokdo islands. Thirty-three fungal strains were isolated from these native plants. All the endophytic fungi were analyzed by internal transcribed spacer (ITS) sequencing (ITS containing ITS1, 5.8s, and the ITS2 region). Waito-c rice seedlings were treated with fungal culture filtrates to test their plant growth-promoting activity. A bioassay of the D-So-1-1 fungal strain isolated from S. oryzifolium confirmed that it has the highest plant growth-promoting activity. All the endophytic fungi belong to four orders: Eurotiales (86%), Capnodiales (3%), Hypocreales (4%), and Incertae sedis (7%). The endophytic fungi were classified as Ascomycota, which contained Aspergillus (12%), Cladosporium (3%), Eurotium (3%), Fusarium (18%), Microsphaeropsis (6%), and Penicillium (58%) at the genus level.

• Korean Journal of Ichthyology
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• v.25 no.2
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• pp.65-73
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• 2013

Egg development and early life history of the Korean spine loach, Iksookimia pumila was investigated to provide basic information regarding biological characteristics and restoration. Adult fish were sampled using spoon net in the Baek Stream, Sangseo-myeon, Buan-gun, Jeollabuk-do, Korea, 7 July 2010. Eggs and sperms were obtained from the females and male with Ovaprim injecting (0.5 mL/kg) and then fertilized using the dry method in the laboratory. Number of spawned eggs were 1,107 (352~1,440). Spawned eggs were slightly adhesive, light yellowish coloring and measured $1.3{\pm}0.04$ mm (mean${\pm}$SD) in diameter. Spawned eggs hatched out 52 (47~55) hours after fertilization at water temperature of $23^{\circ}C$, and newly hatched larvae an average were $4.7{\pm}0.14$ mm in total length. At 5 days after hatching, larvae averaged $7.1{\pm}0.20$ mm in total length and their yolk sacs had been completely absorbed. Beginning at 17 days after hatching, fish entered the juvenile stage and reached $11.0{\pm}0.50$ mm in total length. At 100 days after hatching, the band patterns and external form of juvenile fish were similar to those of adults, and they averaged $31.3{\pm}3.98$ mm in total length.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.896-907
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• 2016

The habitat characteristics of Aconitum austrokoreense Koidz. were investigated to provide basic data for conservation and restoration. The altitude ranged from 260m to 728m with inclinations of $4-39^{\circ}$. As a result of vegetation survey within natural populations, a total of 147 taxa were identified inside 20 quadrates in 7 natural habitats. The importance value of Aconitum austrokoreense was 23.0% based on the coverage and frequency of the herbaceous layer and sat is more dominant. Species diversity was 1.23, and dominace and evenness were found to be 0.22 and 0.77, respectively. The soil type were silty loam (four sites), sandy loam (two sites) and loam (one site). The average field organic matter was 7.83% and the total nitrogen and pH were 0.35, and 5.69. Correlation analysis between environmental factors and population characteristic showed the correlations between chlorophyll content and slope, flowering rate and soil humidity. Conservation on habitats conditions is important for stable maintenance the flora and the surrounding area including habitats has to be designated a protection area for habitats conservation.

• Korean Journal of Ichthyology
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• v.26 no.2
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• pp.89-98
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• 2014

Eggs development and early life history of the endangered Korean dwarf loach, Kichulchoia brevifasciata (Teleostei: Cobitidae) was investigated to provide basic information regarding biological characteristics and restoration. Adult fish specimens were sampled using a spoon net at Geurnsan-myeon, Goheung-gun, Jeollanam-do, Korea from June to July 2011. Since, spawning characteristics were analyzed, and females were induced to spawn by injecting Ovaprim (0.5 mL/kg) and their eggs were artificially fertilized with sperms by the dry method in the laboratory. Total length of mature female were 46~76 mm with GSI $9.6{\pm}3.77%$, and total length of mature male was 42~52 mm with GSI $3.5{\pm}1.04%$. Sex ratio (♂/♀) was 0.10, and there were no secondary sexual characteristics. The number of mature eggs was averaged $60{\pm}28.7$ per female. The lemon yellow eggs were slightly adhesive $1.46{\pm}0.07mm$ in diameter. The embryo hatched approximately 66 h after fertilization at $25^{\circ}C$, and the hatched larvae were averaged $5.5{\pm}0.07mm$ in total length (TL). At 6 days after hatching, the larvae averaged $9.0{\pm}0.29mm$(TL) and their yolk sac was completely absorbed. At 17 days after hatching, they entered the juvenile stage and reached $12.6{\pm}0.24mm$ (TL). At 80 days after hatching, the band patterns and external form of the juveniles were similar to those of adults, and they averaged $33.0{\pm}2.19mm$(TL).

• Journal of Wetlands Research
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• v.20 no.1
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• pp.27-34
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• 2018

Reproductive phenology and physiological responses of Epilobium hirsutum L. to moisture content and nutrient content of soil were analysed in order to obtain basic data for effective conservation and restoration. Epilobium hirsutum L. is a perennial plant. But Epilobium hirsutum L. grew reproductively in all moisture and nutrient gradients. Flower bud, flowers and peduncle were respectively ripened in earlier under highest moisture condition and highest nutrient condition. And, number of flowers and peduncle were more quickly increased under highest moisture condition and highest nutrient condition. Chlorophyll content was high under highest moisture condition and higher middle moisture condition. However, we found no significant difference of chlorophyll content regard to nutrient gradients. There was no difference in minimum chlorophyll fluorescence among all moisture and nutrient gradients. The photochemical efficiency values of PS II were 0.75 in all moisture gradients, and it was 0.78 in highest nutrient gradient. The chlorophyll content of Epilobium hirsutum L. increased as the moisture content increased, and the Fv/Fm value increased as the organic matter increased. Our results showed that high moisture and nutrient content of soil advance their breeding season and promote reproductive growth. It might be important basic informations for the maintenance of population and the management of habitat of Epilobium hirsutum L. an endangered plant species.