• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.531-541
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• 2014

This research investigated the reproduction cycle, litter size, and the effects of factors of red-tongue viper snake inhabiting in Jeju Island, to delve into their life strategy. Field survey was conducted in Jeju Island from May 2006 to November 2008. Reproduction cycle was analyzed through measurements of testis and follicle sizes in laboratory from March 2009 to December 2010. According to the research results, the sizes of red-tongue viper snake's testis and follicle clearly changed seasonally. The number of eggs within the oviduct were greater on the right side ($2.6{\pm}1.0$ eggs, n=16) than on the left side ($1.8{\pm}0.5$ eggs, n=16) (t=-2,721, p<0.05). Average (${\pm}SD$) of survival litter size (SLS) was $4.4{\pm}1.7$ (1~9, range), while total litter size (TLS) was $4.7{\pm}1.5$ (3~9, range), which were not statistically significant. However, their litter sizes were similar to the number of eggs within the oviduct (t=0.039, P>0.05). Relative litter mass (RCM) was $0.42{\pm}0.13$ (0.18~0.79, n=33), and tended to increase, as maternal condition of pre-parturition (MCPPI) was getting better. The sexual ratio of delivered litters showed no significant difference between male and female red-tongue viper snakes (♂:♀ = 1.15:1, n=73 ; ${\chi}^2$=0.342, P>0.5). Average neonate mass showed a weak correlation with maternal mass of pre-parturition (MMPP1) (r=0.387, P<0.05, n=33). Average neonate Snout-vent length (SVL) also demonstrated a weak correlations with maternal SVL (r=0.399, P<0.05, n=33) and MMPP1 (r=0.344, P<0.05, n=33). Average neonate mass and maternal SVL approached significant probability (r=0.323, P=0.067, n=33). This indicates that mother snakes can bear bigger litter due to its larger size. In some cases, litter's weight decreases as mother snakes are bearing more litter; however, the red-tongued viper snake did not show such exchange relationship. From this, it can be conjectured that a red-tongued viper snake has peculiarity of its own species. The research results are predicted to be used as the basis to find a life history of red-tongued viper snake.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.49-59
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• 2009

Seasonal changes of the growth characteristics and biomass of Scirpus fluviatilis, a aquatic emergent vascular plant, were investigated to reveal the phenology and the population dynamics and to provide the fundamental resources for the restoration counterplan of the wetland vegetation in the littoral zone of the Upo wetland, Changnyeong-gun, Gyeongsangnam-do, Korea from March 2006 to November 2006. Scirpus fluviatilis was distributed commonly in Upo, Mokpo, Sajipo, Jokjibyeol, and Topyeongcheon upstream and downstream of Upo wetland, and the density was highest in Mokpo. Distribution range for the water depth was 9~49cm, and the highest shoot density in 26~49cm, and the mean shoot density was $119/m^2$, and the mean shoot length was 122.3cm on May 28. The number of the tuber was $104.5/0.25m^2$, and the living tubers were 84.2%. The mean fresh biomass of the living tubers was 3.0g, and those of 1~4g was most as 57.9%. Germination rates of the living tubers was 43.8%, and the maximum rate was in 7~9g and more than 10g. In the pot cultivation, the shoot density of the germinated tubers and the dormant tubers were highest as 13.5 and 9.7, respectively in early August. In the field study, the shoot density had few change before typhoon damage, while the density increased abruptly in November after flooding accompanied with the typhoon 'Ewiniar'. The shoot length in the pot cultivation and in the field study were 100~116cm and 60~170cm, respectively in the growth-end. Biomass allocation rates into the stem, leaf, flower, and underground parts were 8.9%, 6.6%, 0%, and 84.5%, respectively in the pot cultivation of the germinated tubers, and those of the dormant tubers were 7.1%, 7.1%, 0%, and 85.8%, respectively. The tuber number increased to 1.4~4.1 times by the growth-end, so it is concluded that Scirpus fluviatilis is mostly propagated by the vegetative reproduction.

• Journal of agriculture & life science
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• v.45 no.1
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• pp.101-107
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• 2011

A Total of 48,101 performance records of sows for Yorkshire and Landrace breeds were collected from swine breeding farms in Korea from 2001 to 2008. A general ingredient analysis included the fixed effects of breed, parity, year, season, and farm. For the number of heads per 1st parity analysis by each growth traits, the data of 48,101 heads was used to analyze growth traits group. In the general ingredient analysis, the results showed high significance except for lean percentage by season (p<0.05). Average daily gain of Landrace breed ($640.48{\pm}0.749g$) was better than that of Yorkshire breed ($624.22{\pm}0.608g$), and the backfat thickness of Yorkshire breed ($13.44{\pm}0.030mm$) was thicker than that of Landrace breed ($12.50{\pm}0.037mm$). For the number of born alive and number of stillborn by growth traits for each breed, number of born decreased after test end day of 161 to 165 day, and average daily gain of 620 g to 640 g and the highest number of born appeared at the backfat thickness of 13 mm to 14 mm for yorkshire breed. In case of Landrace breed, number of born was the highest, and the number of stillborn increased together with average daily gain. The number of born was high when backfat thickness was less than 11 mm. The number of born trended to decrease when backfat thickness increased.

• Korean Journal of Environment and Ecology
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• v.33 no.4
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• pp.422-439
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• 2019

The rear edge population is considered to have low genetic diversity and high risk of extinction according to a highly isolated distribution. However, the rear edge population is observed to have persisted for an extended period despite the low genetic diversity. As such, it is necessary to understand the ecological process involved in the persistence of the population. Viola mirabilis L. in Korea is considered the rear edge population from the perspective of the worldwide distribution. We surveyed the distribution range of V. mirabilis, which shows the isolated distribution in the central area of Korea, to find out the factors of its persistence. Next, we investigated and accessed the vegetational pattern of habitats, soil environment, phenology, self-compatibility, population structure, and extinction risk factors observed in the distribution area. V. mirabilis was distributed in the understory of the deciduous forest, planted forest of the deciduous conifer and deciduous broad-leaved trees, shrubland, and grassland in the limestone area. We also observed the re-establishment of seedlings in the population, and most of them showed a stable population structure. For chasmogamous flowers, the visit by pollinators has a significantly positive relationship with the production of fruits. However, we found that the production of the cleistogamous flowers was more numerous in all studied populations and that only the cleistogamous flowers were produced despite a more substantial plant size in some populations. The plant size was more related to the production of the cleistogamous flowers than that of the chasmogamous flowers. Accordingly, the cleistogamous flowers significantly contributed to seedling recruitment in the population. We found that the production of the chasmogamous flowers and the cleistogamous flowers did not have a correlation with the factors of the soil analysis except for phosphoric acid. V. mirabilis showed the self-incompatibility characteristics most likely due to the production capability of the cleistogamous flowers. Potential extinction risk factors observed in the distribution area was included the development of limestone mine, the expansion of agricultural fields, and the construction of houses. Although V. mirabilis showed an isolated distribution in the limestone area in the Korean peninsula, it showed a diverse distribution in a wide habitat environment ranging from the grassland to the understory of the trees with relatively low canopy closure rate. Moreover, we concluded that the persistence of the population was possible if we can maintain the current state of multiple populations and stable population structure.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.1-25
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• 1982

Limnological study on the physico-chemical properties and biological characteristics of the Lake Ok-Jeong was made from May 1980 to August 1981. For the planktonic organisms in the lake, species composition, seasonal change and diurnal vertical distribution based on the monthly plankton samples were investigated in conjunction with the physico-chemical properties of the body of water in the lake. Analysis of temperature revealed that there were three distinctive periods in terms of vertical mixing of the water column. During the winter season (November-March) the vertical column was completely mixed, and no temperature gradient was observed. In February temperature of the whole column from the surface to the bottom was $3.5^{\circ}C$, which was the minimum value. With seasonal warming in spring, surface water forms thermoclines at the depth of 0-10 m from April to June. In summer (July-October) the surface mixing layer was deepened to form a strong thermocline at the depth of 15-25 m. At this time surface water reached up to $28.2^{\circ}C$ in August, accompanied by a significant increase in the temperature of bottom layer. Maximum bottom temperature was $r5^{\circ}C$ which occurred in September, thus showing that this lake keeps a significant turbulence Aehgh the hypolimnial layer. As autumn cooling proceeded summer stratification was destroyed from the end of October resulting in vertical mixing. In surface layer seasonal changes of pH were within the range from 6.8 in January to 9.0 in guutuost. Thighest value observed in August was mainly due to the photosynthetic activity of the phytoplankton. In the surface layer DO was always saturated throughout the year. Particularly in winter (January-April) the surface water was oversaturated (Max. 15.2 ppm in March). Vertical variation of DO was not remarkable, and bottom water was fairly well oxygenated. Transparency was closely related to the phytoplankton bloom. The highest value (4.6 m) was recorded in February when the primary production was low. During summer transparency decreased hand the lowest value (0.9 m) was recorded in August. It is mainly due to the dense blooming of gnabaena spiroides var. crassa in the surface layer. A. The amount of inorganic matters (Ca, Mg, Fe) reveals that Lake Ok-Jeong is classified as a soft-water lake. The amount of Cl, $NO_3-N$ and COD in 1981 was slightly higher than those in 1980. Heavy metals (Zn, Cu, Pb, Cd and Hg) were not detectable throughout the study period. During the study period 107 species of planktonic organisms representing 72 genera were identified. They include 12 species of Cyanophyta, 19 species of Bacillariophyta, 23 species of Chlorophyta, 14 species of Protozoa, 29 species of Rotifera, 4 species of Cladocera and 6 species of Copepoda. Bimodal blooming of phytoplankton was observed. A large blooming ($1,504\times10^3\;cells/l$ in October) was observed from July to October; a small blooming was present ($236\times10^3\;cells/l$ in February) from January to April. The dominant phytoplankton species include Melosira granulata, Anabaena spiroides, Asterionella gracillima and Microcystis aeruginota, which were classified into three seasonal groups : summer group, winter group and the whole year group. The sumner group includes Melosira granulate and Anabaena spiroides ; the winter group includes Asterionella gracillima and Synedra acus, S. ulna: the whole year group includes Microtystis aeruginosa and Ankistrodesmus falcatus. It is noted that M. granulate tends to aggregate in the bottom layer from January to August. The dominant zooplankters were Thermocpclops taihokuensis, Difflugia corona, Bosmina longirostris, Bosminopsis deitersi, Keratelle quadrata and Asplanchna priodonta. A single peak of zooplankton growth was observed and maximum zooplankton occurrence was present in July. Diurnal vertical migration was revealed by Microcystis aeruginosa, M. incerta, Anabaena spiroides, Melosira granulata, and Bosmina longirostris. Of these, M. granulata descends to the bottom and forms aggregation after sunset. B. longirostris shows fairly typical nocturnal migration. They ascends to the surface after sunset and disperse in the whole water column during night. Foully one species of fish representing 31 genera were collected. Of these 13 species including Pseudoperilnmpus uyekii and Coreoleuciscus splendidus were indigenous species of Korean inland waters. The indicator species of water quality determination include Microcystis aeruginosa, Melosira granulata, Asterionelta gracillima, Brachionus calyciflorus, Filinia longiseta, Conochiloides natans, Asplanchna priodonta, Difflugia corona, Eudorina elegans, Ceratium hirundinella, Bosmina longirostris, Bosminopsis deitersi, Heliodiaptomus kikuchii and Thermocyclops taihokuensis. These species have been known the indicator groups which are commonly found in the eutrophic lakes. Based on these planktonic indicators Lake Ok-Jeong can be classified into an eutrophic lake.

• Journal of Wetlands Research
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• v.18 no.4
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• pp.474-480
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• 2016

In this study, formation background of biodiversity and its changes in the process of geologic history, and effects of climate change on biodiversity and human were discussed and the alternatives to reduce the effects of climate change were suggested. Biodiversity is 'the variety of life' and refers collectively to variation at all levels of biological organization. That is, biodiversity encompasses the genes, species and ecosystems and their interactions. It provides the basis for ecosystems and the services on which all people fundamentally depend. Nevertheless, today, biodiversity is increasingly threatened, usually as the result of human activity. Diverse organisms on earth, which are estimated as 10 to 30 million species, are the result of adaptation and evolution to various environments through long history of four billion years since the birth of life. Countlessly many organisms composing biodiversity have specific characteristics, respectively and are interrelated with each other through diverse relationship. Environment of the earth, on which we live, has also created for long years through extensive relationship and interaction of those organisms. We mankind also live through interrelationship with the other organisms as an organism. The man cannot lives without the other organisms around him. Even though so, human beings accelerate mean extinction rate about 1,000 times compared with that of the past for recent several years. We have to conserve biodiversity for plentiful life of our future generation and are responsible for sustainable use of biodiversity. Korea has achieved faster economic growth than any other countries in the world. On the other hand, Korea had hold originally rich biodiversity as it is not only a peninsula country stretched lengthily from north to south but also three sides are surrounded by sea. But they disappeared increasingly in the process of fast economic growth. Korean people have created specific Korean culture by coexistence with nature through a long history of agriculture, forestry, and fishery. But in recent years, the relationship between Korean and nature became far in the processes of introduction of western culture and development of science and technology and specific natural feature born from harmonious combination between nature and culture disappears more and more. Population of Korea is expected to be reduced as contrasted with world population growing continuously. At this time, we need to restore biodiversity damaged in the processes of rapid population growth and economic development in concert with recovery of natural ecosystem due to population decrease. There were grand extinction events of five times since the birth of life on the earth. Modern extinction is very rapid and human activity is major causal factor. In these respects, it is distinguished from the past one. Climate change is real. Biodiversity is very vulnerable to climate change. If organisms did not find a survival method such as 'adaptation through evolution', 'movement to the other place where they can exist', and so on in the changed environment, they would extinct. In this respect, if climate change is continued, biodiversity should be damaged greatly. Furthermore, climate change would also influence on human life and socio-economic environment through change of biodiversity. Therefore, we need to grasp the effects that climate change influences on biodiversity more actively and further to prepare the alternatives to reduce the damage. Change of phenology, change of distribution range including vegetation shift, disharmony of interaction among organisms, reduction of reproduction and growth rates due to odd food chain, degradation of coral reef, and so on are emerged as the effects of climate change on biodiversity. Expansion of infectious disease, reduction of food production, change of cultivation range of crops, change of fishing ground and time, and so on appear as the effects on human. To solve climate change problem, first of all, we need to mitigate climate change by reducing discharge of warming gases. But even though we now stop discharge of warming gases, climate change is expected to be continued for the time being. In this respect, preparing adaptive strategy of climate change can be more realistic. Continuous monitoring to observe the effects of climate change on biodiversity and establishment of monitoring system have to be preceded over all others. Insurance of diverse ecological spaces where biodiversity can establish, assisted migration, and establishment of horizontal network from south to north and vertical one from lowland to upland ecological networks could be recommended as the alternatives to aid adaptation of biodiversity to the changing climate.