• Journal of Ecology and Environment
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• v.43 no.2
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• pp.104-116
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• 2019

Background: The composition of wild bird populations in temperate zones greatly varies depending on phenological changes rather than other environmental factors. Particularly, wild birds appearing in wetlands fluctuate greatly due to the crossover of species arriving for breeding during the summer and for wintering. Therefore, to understand the changes to species composition related to phenology, we conducted this basic analysis of populations to further the cause of the protection of wetland-dependent wild birds. Methods: It is wrong to simply divide a wild bird population investigation into seasons. This study identifies species composition and indicator species that change along with seasons. Wetlands to be surveyed are protected by natural monuments and wetland inventory and are in a state close to nature. In order to identify as many species as possible in wetlands, a survey was conducted in both shallow and deep wetlands. The water depth varied in these areas, ranging from 0.2 to 2.0 m, allowing for both dabbling and diving ducks to inhabit the area. Surveys were conducted using line-transect and distance sampling methods and were conducted at intervals of 2 weeks. The survey was conducted under the following three categories: the eco-tone and emergent zone, the submergent zone, and the water surface. The survey was conducted along a wetland boundary by observing wild birds. A PC-ord program was used for clustering, and the SAS program was used to analyze the changes in species composition. The data strongly indicates that day length is the main factor for seasonal migration periods, despite the fact that climate change and increasing temperatures are often discussed. Results and conclusions: The indicator species for determining seasons include migrant birds such as Ardea cinerea, Alcedo atthis, Anas penelope, and Poiceps ruficollis, as well as resident birds such as Streptopelia orientalis and Emberiza elegans. Importantly, increases in local individual counts of these species may also serve as indicators. The survey results of seasonal fluctuations in temperate zones shows that spring (April to June), summer (July to September), autumn (October), and winter (November to March) are clearly distinguishable, even though spring and summer seasons tend to overlap, leading to the conclusion that additional research could more clearly identify fluctuation patterns in species composition and abundance in the study area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.296-313
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• 1982

At a time when world population and food supply are in a delicate balance, it is essential that we look at factors to improve this balance. We can alter the environment to better fit the plant's needs, or we can alter the plant to better fit the environment. Improved technology has allowed us to increase the yield level. For moderately detrimental weather events technology has generally decreased the yield variation, yet for major weather disasters the variation has increased. We have raised the upper level, but zero is still the bottom level. As we concentrate the production of particular crops into limited areas where the environment is closest to optimum, we may be increasing the risk of a major weather related disaster. We need to evaluate the degree of variability of different crops, and how weather and technology can interact to affect it. The natural limits of crop production are imposed by important ecological factors. Production is a function of the climate, the soil, and the crop and all activities related to them. In looking at the environment of a crop we must recognize these are individuals, populations and ecosystems. Under intensive agriculture we try to limit the competition to one desired species. The environment is made up of a complex of factors; radiation, moisture, temperature and wind, among others. Plant response to the environment is due to the interaction of all of these factors, yet in attempting to understand them we often examine each factor individually. Variation in crop yields is primarily a function of limiting environmental parameters. Various weather parameters will be discussed, with emphasis placed on how they impact on crop production. Although solar radiation is a driving force in crop production, it often shows little relationship to yield variation. Water may enter into crop production as both a limiting and excessive factor. The effects of moisture deficiency have received much more attention than moisture excess. In many areas of the world, a very significant portion of yield variation is due to variation in the moisture factor. Temperature imposes limits on where crops can be grown, and the type of crop that can be grown in an area. High temperature effects are often combined with deficient moisture effects. Cool temperatures determine the limits in which crops can be grown. Growing degree units, or heat accumulations, have often been used as a means of explaining many temperature effects. Methods for explaining chilling effects are more limited.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1226-1232
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• 2007

Phellinus linteus is a well-known Oriental medicinal fungus that has various biological activities, including immunomodulatory and anti-tumor activities, the mechanisms of which are poorly understood. In the present study, we investigated the anti-proliferative activity of the methanol extract of P. linteus-Barley corn (MEPLB) in human lekemic U937 cells. It was found that exposure of U937 cells to MEPLB resulted morphological change and growth inhibition in a dose-dependent manner as measured by trypan blue count and MTT assay. Upon treatment with MEPLB, U937 cells developed many of the hallmark features of apoptosis, including condensation of chromatin and an increase in the sub-G1 population suggesting that the anti-proliferative effect of MEPLB is associated with the induction of apoptosis. The anti-proliferative and apoptotic effects of MEPLB were connected with a marked induction of the pro-apoptotic Bax and cyclin-dependent kinase (Cdk) inhibitor p21 in a p53-independent manner. Additionally, MEPLB treatment significantly induced the caspase-3 activity in U937 cells. Taken together, the present results suggest that apoptotic signals evoked by MEPLB in human leukemic U937 cells may converge caspase-3 activation through an up-regulation of Bax rather than a down-regulation of Bcl-2 or Bel-xL.

• Korean Journal of Plant Resources
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• v.8 no.2
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• pp.165-173
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• 1995

This study was conducted to clarify not only the phytogeographical distribution but also species characteristics of Korean-native Anacardiaceae. 6 species of I genus were ascertained from herbarium specimens and field survey of natural population. Rhus verniciflua have been mainly cultivated in Wonju region, Kangwon-do and Hamyang region, Kyeongsangnam-do, could be cultivated in all parts of Korea, especially more in cold area. R. trichocarpa was distributed in all parts except for some far-islands of South in Korea. Petiole was especially reddish. Fruits are matured in June-July, and have stiff trichomes. R. sylvestris was widely distributed in the subtropical-temperate and temperate zone, and mainly distributed in the seashore and islands under 36$^{\circ}$ in Korea. Leaflets and petiole was reddish, and fruits were glabrous. R succedanea was only distributed in Jeju-do and several islands which is subtropical zone in Korea. Leaflets were lanceolate to oblong, characterized by little trichomes. R.chinensis is a ubiquitous tree which is widely distributed in the temperate zone, in Korea, and ranged perpendicularly to 800-900m. Inflorescense was characterized by apical site. Fruit was covered with dense short hairs and sometimes milky latex. R. ambigua was only distributed in subtropical zone, native in Kwang-do and Sangbaek-do, Yeochon-gun, Chunlanam-do in Korea. Especially, this species was a vine, trifoliolate and most poisonous. Leaflets were coriaceous, glabrous, and revolute type.

• Korean Journal of Health Education and Promotion
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• v.6 no.1
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• pp.22-33
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• 1989

Rapid socio-cultural and economic changes in the country has brought with it changes in the society's value system. For a traditional society that is increasingly being exposed to modernization but where sex norms are still very restrictive, the adolescent sexual mores takes on added significance. Adolescents are caught between two opposing forces, the changing environment that allows for freer and liberal mores and the traditional society that cannot keep pace with the changing environment and therefore demands resistance to changes. This paper focuses on problems of adolescent sexuality in this country and considers the countermeasures for the existing problems. Amongst the problems are: (a) increasingly younger age of the adolescents who start sexual intercourse (b) non-use of contraception, (c) unwanted pregnancies, (d) increase in the number of induced abortion and (e) increase in the number of unwanted children and unmarried mothers. The Korean adolescent's sexual behavior seems to follow that of the developed countries. In other words, many western modes of life and sexual values seem to bave been copied in Korea and yet Korean adolescents lack in their knowledge of sex related matters such as reproductive physiology and contraception. Among middle and high school students, female students are reported to have less knowledge on sex than male students according to a 1988 survey by KIPH. Even among the unmarried famale factory workers, only 42.5 percent replied they know of the condom, and 25.1 percent and 23.1 percent said they had knowledge of spermicide and menstrual regulation respectively. However, 14.9 percent and 13.9 percent reported that they had a knowledge of the loop and female sterilization respectively according to the 1984 study by KIPH. Among the middle school students 0.8 percent said they had experience in sexual intercourse, while 7.3 percent of the high school students reported having had sexual intercourse. The sexual intercourse experience rate among the unmarried female factory workers is 37.8 percent. Among those female factory workers with sexual experience, 46.7 percent had more than one sex partners. Only 39.1 percent of male students and 18.9 percent of female students among those with sexual intercourse experience have used contraceptives. mostly condoms and oral pills 45.1 percent of female factory workers with sexual intercourse experience used contraceptives such as pills, condoms and rhythm methods. The pregnancy experience rate among the female factory workers who had experience in sexual intercourse is 29.5 percent, which is 11.1 percent among the total respondents. Out of the 102 pregnant female workers, 98 workers(96.1 percent) terminated their pregnancy by induced abortion and 2 workders(2 percent) in natural abortion, while 1 worker(1 percent) was in pregnancy and another 1 worker had normal birth that was subsequently sent to orphanage. In order to cope with the problem of adolescent sexuality, a drastic and strong policy measures should be taken by the government. The most effective countermeasure to the adolescent sexual problems appears to the education. The sex and population education in the school is very much in need. In addition, sex education program through mass media and at the job sit-should be promoted for a healthy development of adolescents' sexual behavior. Also, the existing national family planning program, which has focused on the married couples, should be extended to the unmarried people in its scope and contents of the program.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.327-333
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• 2005

For the first time in Korea, plant size, distribution pattern and root growth form of Tamarix chinensis were surveyed at natural stand in Shiwha Lake, from June to July in 2005. T, chinensis grew in the range of 350 m towards north-south and 270 m in east-west direction. The mean number of stems germinated from same root system was 1.9. On the stem base, the numbers of living and dead plants were 1,398 and 114, respectively. Mean perimeter and height of 1,398 plants were $5.9{\pm}3.2$ cm and $159{\pm}51$ cm, respectively. By dividing into 10 classes based on the perimeter size, the largest number of plants were included in the second smallest class category. However, by dividing into 10 classes on the bases of plant height, variation in the number of plants along the height showed normal distribution curve. The heights of dead plants were small in perimeter but diverse in height. On the root base, the number of plants was the greatest in the smallest size class, and conspicuously decreased with size increment. Distribution of T. chinensis was clumped pattern. Age of the largest plant was 8-year. T. chinensis had two types of root growth. One was horizontal growth in the periphery of soil surface, and the other vertical growth.

• Journal of the Korean earth science society
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• v.34 no.3
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• pp.235-248
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• 2013

The purpose of this study is to investigate a feasibility of a small mountain as a field work site on geological features in Earth sciences classes at all levels. Mt. Geumdang with the height of 305 meters from the sea level is located in the metropolitan city of Gwangju, southern part of Korea. The study reviews the human and natural geography, geological features, geomorphic resources, landscapes, and conveniences of the mountain for a possibility of meaningful field work. The population within the distance of 5 km from the mountain stands at about 620,000 and 170,000 of them are students and teachers. Mt. Geumdang has a warm temperature climate with low rainfall throughout the year, so it seems suitable for a field survey. Road network and public transportation system around the area are well-developed and easily accessible. Mt. Geumdang shows various rock type and geological structures. The basement rock is Gwangju granite, which is plutonic body of the Jurassic period. Also, granophyre (micrographic granite) and various volcanic rocks distributed as bedded tuff, lapilli tuff, and rhyolite of the Cretaceous period. Many andesitic and felsic dykes were intruded into the rock by joint system. In Mt. Geumdang, many geomorphic resources are found such as U shaped mountain, joint, fault, lamination, gnamma, tor, cliff, groove, block stream and block field, regolith, and saprolite. It has a beautiful mountain scenery including the view of whole shape of Mt. Mudeung, panoramic view of the town, Pungam lake, World Cup stadium and sunrise and sunset. Furthermore, the area has ecologic study facilities related to geology, emergency medical and convenience facilities for field works. In conclusion, Mt. Geumdang is highly feasible for geological field studies at all levels.

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.127-151
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• 1989

The ground beetles or carabids are essentially predaceous feeding on a wide variety of insects including forest pests, slugs and land snails containing those injurious to livestock or veterinary, thus many are predominantly beneficial and serve as natural enemies. In the present investigation, some morphometric multivariate analysis were done for 9 different populations in 5 subspecies of D. (C.) jankowskii, which are one of the most common ground beetles in Korea As the results, when the comparison was conducted between intraspecific groups regardless of subspecies in external morphological characters, the average group membership revealed 97.46% correct assignment For intersubspecific comparisons alone 96.3% were correctly classified. Between the groups of ssp. jankowskii an average of 100% individuals were classified in their known group. Thus the predict group membership was highly significant(P<0.001), exceeding so-called 'the 75% rule'. Whereas, the average group membership using the male genitalic characters represented less than the 75% assignment, except only in ssp. quelpartianus (85.6%). The population from Is. Chindo were described here as a new subspecies for qualitative as well as the resultant quantitative differences. Therefore, a total of 7 subspecies are represented in Korea. Among them, the nominate subspecies, ssp. jankowskii(sensu lato), revealed distinct intrasubspecific differences between different geographic populations. These differences can be as notable as intersubspecific variation which need substantial revision of the previous intuitional concepts on the infraspecific level.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.196-202
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• 2014

In order to select superior trees based on fruit characteristics and provide basic informations necessary for their improvement, total 107 individual trees of Sorbus alnifolia (Sieb. et Zucc.) K. Koch were selected from 11 wild populations in South Korea. After collecting normal fruit branch, we investigated morphological characteristics of fruit and then considered its relationship among the 11 populations by multivariate analysis method. Results from principal compound analysis showed that it represented 85.8% accumulated explanation from five principal compounds. According to cluster analysis based on fruit characteristics, the natural S. alnifolia populations were classified into four groups and Mt. Mani population was different from other populations. Selection effect with outstanding candidate trees including superior 5 individual trees (Gwangyo 1, Gwangyo 2, Deogyu 7, Mani 29, Mani 30) was estimated at 122.8%, 115.5% and 182.7% in fruit width, length and yield per fruit bunch, respectively. The object of this results will give us invaluable information about breeding by selection of S. alnifolia in south Korea.

• Korean Journal of Poultry Science
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• v.40 no.4
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• pp.379-388
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• 2013

Avian paramyxovirus (APMV) type 4 and 6 were isolated during an avian influenza (AI) surveillance program of wild birds. This study also conducted experimental infection of wild-bird-origin APMV type 4 and 6 in specific pathogen free (SPF) chickens to study pathogenicity and transmission within domestic flocks. In addition, serological prevalence data of APMV type 4 and 6 in domestic fowls was conducted with chicken sera collected from 2007 to 2009 in order to understand infection status. The results of the animal experiment showed that APMV type 4 and 6 had the ability to infect chickens with sero-conversion and to transmit the virus from infected birds to contacted birds, but showed low pathogenicity. Serological tests revealed that APMV type 4 was widespread in the poultry industry, especially in layer flocks, but the positive rate for APMV type 6 was very low. This study concluded that wild bird-origin APMV type 4 and 6 could infect the chickens by inter-species transmission and the seroprevalence of APMV type 4 was quite high in Korean poultry. However, since almost all the chicken flocks had a high level of antibody titer against APMV type 1, there was possibility of cross reaction between APMV type 1 and 4, which made the interpretations more complicated. In order to understand infection status in the natural environment, additional study is necessary regarding the seroprevalence of APMV type 4 and 6 in the wild bird population.