• The Korean Journal of Ecology
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• v.6 no.4
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• pp.10-20
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• 1983

Morphological and ecological comparions are made between specimens of Cobitis koreensis KIM and the geographically restricted population of the Cobitid fish which is found along the Begchon stream, Puangun, Cholla-bugdo province over a 12-month period of 1982 and 1983. The Begchon population is tentatively identified as Cobitis koreensis, but the color patterns and two morphometric proportions differ widely fromthose reported previously for this species. In addition to these character, it is easily distinguished from C. koreensis by the smaller body size, by having the larger egg size and the less egg number in female during the breeding season. As the differentiation of this population is primarily due to geographically isolation, it is supposed that Begchon cobitid population may be an undescribed distinct subspecies of K. koreensis or above the conventional subspecies level.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.374-381
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• 2012

In this study, ecological characteristics of Zacco platypus population in Lake Hoengseong region, including the up-and downstream in Lake, were investigated from April to November, 2010. The results compared with regional dynamics of Z. platypus population showed a dominant population among the other fish population, and also upstream has relatively high as 1,707 (78.70%) individuals than those of other sites. The regression coefficient (b) in relation to length-weight on Z. platypus population were 3.28 which appeared relatively a stabilized habitat condition in Lake Hoengseong region and 3.28 at the upstream and 3.10 in Lake Hoengseong and 3.09 at the downstream. Condition factor on Z. platypus population in Lake Hoengseong region showed stabilized population as 0.003 value, and especially the condition factors at the upstream were relatively higher than those at the downstream and Lake Hoengseong, indicate that Z. platypus population at the upstream displayed to be maintained as the most good condition in relation to trophic states. As a results of compared with body size on Z. platypus population, was investgated as highly distribute between 30~50mm and 70~90mm at upstream; 60~80mm in Lake Heongseong; 70~100mm at downstream, respectively. As a results, Z. platypus population at the upstream among Lake Hoengseong region displayed the most stabilized growth condition, and Z. platypus population were inhabitable in lotic and lentic environments based on good habitat condition.

• Reproductive and Developmental Biology
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• v.36 no.4
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• pp.291-294
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• 2012

Embryonic stem cell classically cultured on feeder layer with FBS contained ES medium. Feeder-free mouse ES cell culture systems are essential to avoid the possible contamination of nonES cells. First we determined the difference between ES cell and MEF by Oct4 population. We demonstrate to culture and to induce differentiation on feeder free condition using a commercially available mouse ES cell lines.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.106-111
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• 2018

The Black-tailed gull (Larus crassirostris) is one of the most common gull species in the Northeast Asia and classified as LC (least concern) in the IUCN Red List. The bird has become a useful indicator for marine environmental pollution and habitat disruption, since the human activities impacted marine environments. Here we show that the black-tailed Gull has 6 haplotypes and some rare haplotypes are locally limited implying that the bird may not disperse far. This study may be the first report on population genetic study of Black-tailed Gull in Korea and could be used as the baseline data for monitoring and genetic study on the bird as an environmental indicator.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.1
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• pp.73-84
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• 2019

In this research, it is a basic study to investigate the population of birds using UAVs. The research area is Ardeidae species(ASP) habitat and has long-term monitoring. The purpose of the study is to compare the ASP populations which analyzed ground observational survey and UAVs imagery. We used DJI's Mavic pro and Phantom4 for this research. Before investigating the population of ASP, we measured the escape distance by the UAVs, and the escape distances of the two UAVs models were statistically significant. Such a result would be different in UAV size and rotor(rotary wing) noise. The population of ASP who analyzed the ground observation and UAVs imagery count differed greatly. In detail, the population(mean) on the ground observation was 174.9, and the UAVs was 247.1 ~ 249.9. As a result of analyzing the UAVs imagery, These results indicate that the lower the UAVs camera altitude, the higher the ASP population, and the lower the UAVs camera altitude, the higher the resolution of the images and the better the reading of the individual of ASP. And we confirmed analyzed images taken at various altitudes, the individuals of ASP was not statistically significant. This is because the resolution of the phantom was superior to that of mavic pro. Our research is fundamental compared to similar studies. However, long-term monitoring for ASP of South Korea's by ground observation is a barrier of the reliability of the monitoring result. We suggested how to use UAVs which can improve long-term monitoring for ASP habitat.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.131-138
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• 2009

Among rumen microbes, bacteria play important roles in the biological degradation of plant fiber due to their large biomass and high activity. To maximize the utilization of fiber components such as cellulose and hemicellulose by ruminant animals, the ecology and functions of rumen bacteria should be understood in detail. Recent genome sequencing analyses of representative fibrolytic bacterial species revealed that the number and variety of enzymes for plant fiber digestion clearly differ between Fibrobacter succinogenes and Ruminococcus flavefaciens. Therefore, the mechanism of plant fiber digestion is also thought to differ between these two species. Ecology of individual fibrolytic bacterial species has been investigated using pure cultures and electron microscopy. Recent advances in molecular biology techniques complement the disadvantages of conventional techniques and allow accurate evaluation of the ecology of specific bacteria in mixed culture, even in situ and in vivo. Molecular monitoring of fibrolytic bacterial species in the rumen indicated the predominance of F. succinogenes. Nutritive interactions between fibrolytic and non-fibrolytic bacteria are important in maintaining and promoting fibrolytic activity, mainly in terms of crossfeeding of metabolites. Recent 16S rDNA-based analyses suggest that presently recognized fibrolytic species such as F. succinogenes and two Ruminococcus species with fibrolytic activity may represent only a small proportion of the total fibrolytic population and that uncultured bacteria may be responsible for fiber digestion in the rumen. Therefore, characterization of these unidentified bacteria is important to fully understand the physiology and ecology of fiber digestion. To achieve this, a combination of conventional and modern techniques could be useful.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.277-286
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• 2006

Population ecology of Cobitis tetralineata was examined at Churyeong Stream, Seomjin River, Korea. C. tetralineata inhabited on the sand bottoms with $10{\sim}20cm/see$ in current velocity, and $30{\sim}150cm$ in water depth. This species was active on the sand during the daylight hours from March to October, but they hibernated in the inside of the sand during the winter season. Sex ratio of female to male was 1:0.57, and female was $20{\sim}30mm$ (TL) larger than male. The age group of C. tetralineata (female) population showed that the $20{\sim}40mm$ group is 0+ years old, the $45{\sim}65mm$ group 1+ years old, the $65{\sim}90mm$ group 2+ years old, and the group longer than 90 mm over 3 years old. Males $13{\sim}14$ months old after hatching had lamina circularis at the base of its pectoral fin as a secondary sexual character. And in its spawning season, lateral color pattern of male was changed as a sexual dimorphism. The spawning season may be from late June to middle July, $22{\sim}26^{\circ}C$ water temperature. The average number of mature eggs in ovary was about $1,288{\pm}583(474{\sim}2,976)$, egg diameter was about $0.98{\pm}0.1mm$. C. tetralineata fed mainly on Chironomidae, Arcellidae, Branchioda and Algae. The feeding rate was the highest in April and September, but they did not fed in the winter.

• Korean Journal of Environment and Ecology
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• v.21 no.4
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• pp.303-310
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• 2007

This study was carried out to investigate vegetation structure and soil properties of Tilingia tsusimensis population found to be distributed in Mt. Gaya and Mt. Keumo. The Tilingia tsusimensis population was classified as Tilingia tsusimensis-typical dominant population and Tilingia tsusimensis-Thalictrum uchiyamai dominant population. It was found out that the organic matter content in the distributed areas for Tilingia tsusiensis population was $25.0{\sim}32.3%$; content of nitrate nitrogen was $0.83{\sim}1.04%;\;5.58{\sim}20.76\;ppm$ for available phosphorous; $46.3{\sim}62.9$ for CEC, and 4.5 to 5.1 for soil pH. The results of the correlation between Tilingia tsusimensis population and environmental factor are as follows; the Tilingia tsusimensis-typical dominant population was found in the areas of low elevation and had somewhat high interchangeable Na, Ca, Mg and CEC among nutrients; on the other hand, Tilingia tsusimensis-Thalictrum uchiyamai-dominant population was found in the areas of somewhat higher elevation and had a little lower interchangeable Na, Ca, Mg and CEC among nutrients than those of the Tilingia tsusimensis-typical dominant population.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.658-675
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• 2016

The environmental characteristics of the habitats, the population structures, ecological niche, life traits and the population demography are used as an essential informations to the effective conservation plans about the target species. We first confirmed a total of 37 populations through 12 years of investigation on the extents, and investigated the environmental factors of habitats and the population structures of the 25 cohorts in 12 regions among them. And, we investigated the population dynamics targeting at 8 cohorts in the population of Daegwanryeong-myeon, Pyeongchang-gun, Gangwon-do. Along with this, we conducted 4 years of cultivation experiments and how pollinators affect the success of reproduction. The results shows that the Paeonia obovata Maxim. was found in a relatively wide range of habitats. For the population structures of the 25 cohorts, there were considerable differences among cohorts, including a case which showed relative stable structure and an extreme case in which only adults were found. The factor that affected the population dynamics during the investigation was thought as a forest gap created in the tree layer. In the cultivation experiment, seedlings grew well in a less soil organic matter. The seed setting rate and the number of seeds generated by visiting pollinators were higher trends. In conclusion, to understand the distribution of the Paeonia obovata Maxim., there needs to be investigated on the other factors that are involved in dispersal factors other than environmental factors, and thus we suggest the necessity of the research on the dispersal vectors. The current Paeonia obovata Maxim. population was thought as a process of expansion after the rapid reduction of the extents in the past. For the effective conservation of the Paeonia obovata Maxim., an endangered plant, we recommend to understand the species through the spatio-temporal expansion, and maintain the health of the ecosystem based on it.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.868-875
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• 2012

This study was carried out to analyze the vegetation properties, soil characteristics and ordination of Hemerocallis hongdoensis population in South Korea. The Hemerocallis hongdoensis population was classified into Mallotus japonicus dominant population, Viburnum wrightii dominant population, Melampyrum setaceum dominant population. Hemerocallis hongdoensis were mainly distributed along the coast of south-western iland of the Korean penninsula and it's population was located at an elevation of 6m to 362m. In the study sites, soil organic matter, total nitrogen, exchangeable potassium, exchangeable calcium, exchangeable magnesium, cation exchange capacity and soil pH were 16.18~21.70%, 0.56~0.97%, 0.42~0.88mg/kg, $3.38{\sim}5.65cmol^+/kg$, $1.12{\sim}2.38cmol^+/kg$, $25.93{\sim}41.45cmol^+/kg$, and 4.45~4.86 respectively. Mallotus japonicus dominant population was found in the steep sloped area that has high percentage of cation exchange capacity and total nitrogen than other populations. Viburnum wrightii dominant population was found gentle sloped area that has low percentage of cation exchange capacity and total nitrogen. Melampyrum setaceum dominant population was found in the medium sloped area that has medium percentage of cation exchange capacity and total nitrogen. Current status of Hemerocallis hongdoensis habitats is very vulnerable with local development constantly threatening the species' survival. Thus, concrete conservation plans to protect natural habitats should be set up as soon as possible.