• Korean Journal of Environment and Ecology
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• v.32 no.5
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• pp.513-531
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• 2018

This study compared forest vegetation in Chungcheongnam-do Provincial Park (Deogsan, Chilgabsan, and Daedunsan) from 2006 to 2016. The results of the analysis on the vegetation of the research sites by the phytosociological method showed that the Deogsan Provincial Park had Quercus mongolica community, Pinus densiflora community, Q. variabilis community, and Zelkova serrata community. Chilgabsan Provincial Park had Q. variabilis community, Q. mongolica community, P. densiflora community, and Carpinus laxiflora community. Daedunsan Provincial Park had Q. mongolica community, Q. variabilis community, Q. serrata community, C. tschonoskii community, C. laxiflora community, P. densiflora community, and Q. acutissima community. The importance value in each Provincial Parks was analyzed as follows. The importance value of Q. mongolica(72.35) was the highest in Deogsan Provincial Park, and followed by P. densiflora(70.25), Q. variabilis(53.11), Styrax japonicus(11.44), Prunus sargentii(11.17), and Fraxinus rhynchophylla(10.41). Q. variabilis(73.34) was the highest in Chilgabsan Provincial Park and followed by, P. densiflora(58.71), Q. mongolica(57.02), C. laxiflora(18.84), Q. serrata(13.48), and Prunus sargentii(13.31). The importance value of Q. mongolica(57.03) was the highest in Daedunsan Provincial Park and followed by Q. variabilis(31.98), Q. serrata(31.53), P. densiflora(16.80), C. tschonoskii(16.50), C. laxiflora(16.07), S. obassia(15.76), and Acer pseudosieboldianum(10.09). The results of DBH analysis of the major species having the high importance value showed the normal density distirbution of Q. mongolica, and Q. variabilis in Deogsan Provincial Park, so the dominance status of these species is likely to continue. Q. variabilis, Q. mongolica, and P. densiflora in Chilgabsan Provincial Park showed the normal density distribution showed the density of normal distribution, so the dominance status of these species is likely to continue. However, the dominance status of C. laxiflora, and Q. serrata is likely to be expanded in the future due to the high density of young individuals. Q. mongolica, and Q. variabilis in Daedunsan Provincial Park showed the density of reverse J-shaped curve, so the dominance status of these species is likely to continue, and C. tschonoskii, and P. densiflora had a formality distribution, suggesting continuous domination of these species over the other species for the time being. Additionally the dominance status of C. laxiflora, and Q. serrata is considered to be expanded in the future due to the high density level of young individuals.

• The Korean Journal of Ecology
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• v.24 no.5
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• pp.281-288
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• 2001

The relationships between the growths of Abies koreana W. and climatic factors were analyzed by the use of tree-ring analysis at the subalpine belt of Mt. Halla National Park. The four cores were extracted from each 21 trees at north-facing slope (1,900m a.s.1.). The site chronology was established on the periods from 1912 to 1999. The growth of A. koreana was very poor, in particular in the years of 1982, 1988 and 1996. Simple correlation was employed to analyze the relationship between the growth of A. koreana and climatic factors. The result of simple correlation indicates that the growth of A. koreana represent positive correlations both with the mean temperatures of April and previous November, and the precipitation of previous December and January. The presence of large number of frost-damaged scars in the individual trees of A. koreana implies that local freezing temperature conditions at Mt. Halla have occurred in 1964, 1965 and 1966. The correlations between the fir chronology SOI(Southern Oscillation Index) of previous January, February and November were significantly positive. The growth ratio of A. koreana demonstrates that this species is sensitive to seasonal variations. As the winter temperature rises, the growth ratio of A. koreana decreases, on the other hand, the increase of autumn temperature accelerates the growth ratio of A. koreana. The growth decline of A. koreana was observed from 51 cores out of the 54 cores, and the overall growth declines have initiated at 1978, 1982 and 1988. Distinct growth decline of A. koreana in the range of 70% is noticed at 34 cores out of the 51 cores. The decline of, A. koreana growth appears to be related to the winter temperature which has increased since mid-1970s.

• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.57-69
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• 2023

The objectives of this study were to analyze the fish community structures and distribution characteristics of fisheries resources in the Osip Stream and Wangpi Stream, fishery resources protection areas. For the study, we conducted fish samplings four times in the two streams from April to October 2019. In Osip Stream and Wangpi Stream, we sampled 31 species and 29 species and the dominant species were Zacco platypus (28.6%) and Squalidus multimaculatus(41.7%), respectively. According to the life type of fish species, primary freshwater species were collected 18 species(58.1%) and 21 species(72.4%), and migration fishes were sampled 4 species (12.9%) and 6 species (20.7%) in Osip Stream and Wangpi Stream, respectively. Fisheries resources species showed high relative abundance in June, and the fish biomass was highest in October. As a results of comparing the previous studies with this study, both rivers showed high biodiversity and were found to maintain stable populations of fishes. According to analysis of tolerance guilds, the proportion of tolerant species, based on the number of individuals, was composed of 14.4% and 1.1% in Osip Stream and Wangpi Stream, respectively. This very low ratio of tolerant species confirmed that both streams have very good physiochemical environment conditions. From the above results, it was judged that the fishery resource protection areas of Osip Stream and Wangpi Stream have high ecological function and preservation value. For sustainable use and management of fishery resource protection areas of Osip Stream and Wangpi Stream, it is suggested that biological disturbance management, fish discharge projects considering environmental capacity, efforts to improve the habitat environment, and establishing a fishery resource protection areas management system were necessary as considerations.

• Journal of Life Science
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• v.33 no.12
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• pp.995-1001
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• 2023

This study investigated the effects of three music genres (classical, new age, and rock) on the stress levels of six Jeju crossbred horses (Jeju horse × Thoroughbred) in a horse stable. The horses were exposed to the three genres for seven days, and their stress levels were measured by analyzing physiological markers, including neurotransmitter (cortisol, β-endorphin, dopamine, serotonin, and oxytocin) plasma levels and creatine phosphokinase (CPK) and aldolase serum levels. The neurotransmitter analysis showed significant differences in cortisol levels between classical and new age music exposure. Dopamine levels decreased significantly only with new age exposure. Although there were no significant differences in β-endorphin levels between the three genres, β-endorphin levels decreased with increasing classical and new age music playback times and increased with increasing rock music playback times. There were no significant differences in serotonin levels between the three genres. Oxytocin levels decreased significantly with exposure to classical and rock music. The CPK and aldolase analyses showed that CPK levels decreased significantly only with exposure to new age music and increased after playback ended, while aldolase levels decreased significantly with classical and new age music exposure and increased after playback ended. These findings suggest that classical music and new age are the optimal music genres for the psychological stability of Jeju crossbred horses. Playing back an appropriate music genre could be used to improve breeding and promote the welfare of Jeju crossbred horses.

• Korea journal of population studies
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• v.17 no.1
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• pp.87-114
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• 1994

1950년대부터 많은 개발도상국가들은 가족계획을 위주로 하는 인구제어정책을 추진하여 왔다. 특히 가부장제도를 중심으로하는 동아시아 국가들에 있어서는 남아선호관이 출산력 저하나 피임 실천율이 증대에 지대한 유해요인으로 일관해 왔다. Sheps(1963)는 실증적으로 2명의 아들을 갖기 위해서는 약 3.9명 정도의 자녀를 두어야 한다는 연구결과를 제시한바 있다. 이와 같은 남아선호관의 여파에도 불구하고 한국과 홍콩은 1980년대 증반에 이미 1.6명 수준의 저출산율을 이룩하였으며, 1970년대에 인구억제 정책을 시작한 중국도 2명 수준으로 저하되어 가족계획사업의 성공사례로 평가되어 왔다. 그러나 이들 국가들의 출산율은 지난 20-30년이라는 짧은 기간에 너무나 급진적으로 감소된 반면에 남아선호관의 상존으로 인한 성비(여자 100명당 남자수)의 불균형을 초래하게 되였다. 한 예로 한국의 경우 1960년도만 해도 6명 이상의 자녀를 출산하는 과정에서 1-2명의 아들을 둘 수 있는 확률은 매우 높았으나, 최근에는 출산율이 2명 이하로 저하되어 아들을 둘 수 있는 확률은 과거보다 3-4배 어려워졌기 때문에 인위적인 방법으로 아들을 두는 부모의 수가 증가하고 있다. 중국은 1970년대 중반기부터 강력히 추진되어온 소위 "한자녀 갖기 운동"으로 인하여 여아출산인 경우 영아살해 또는 출생의 미신고등 많은 사회적 물의를 야기하였고, 최근에는 초음파검사를통한 선택적 인공임신중절(태아가 여아인 경우)으 경우가 급격히 증가하고 있다. 우리 나라의 성비는 출산율이 급격히 감소된 1980년대 증반기부터 급격히 증가되었다. 즉 인구전체에 대한 성비는 1980년의 103.9명에서 1985년에 110명으로 증가하였고ㅡ 1990년 116.9명으로 증가되었다. 성비는 자녀의 수가 적을수록 높아지는 추세이다. 1991년 조사에서 출산을 종료한 부인의 경우 1자녀의 성비는 무려 206명이나 되고 있다. 이와 같은 결과는 한자녀를 원하는 부인이 아들을 둔 경우 1자녀에서 조산을 결심하기 때문인 것이다. 통계청 자료에 의하면 성비는 무엇보다도 자녀의 출산순위와 밀접하다. 1991년 출생신고자료의 경우 첫아이의 출생시 성비는 106.1명이고, 둘째아이가 112.8명이나, 셋째아이는 184.7명으로 크게 증가하고 넷째 이상의 경우는 212.3명이나 된다. 동일한 출산순위라도 이미 두고 있는 자녀의 성에 따라서 많은 차이를 보인다. 1991년도 3번째 출산의 경우 딸만 2명을 두고 있는 자녀의 성에 아들만 2명 또는 아들과 딸을 각각 1명씩 두고 있는 경우에 비해 높은 성비를 보이고 있다. 자녀를 출산하는데 있어서 처음에는 아들ㅇ르 기다리지만 딸의 수가 증가함에 따라 적극적으로 아들을 낳고자 하는 노력을 지속하게 됨을 알 수 있다. 이는 즉 임신한 자녀의 성이 딸로 판명되면 인공임신중절을 통해 임신을 종결시키고 있음을 의미한다. 최근 한국보건사회연구원에서 수행한 연구결과에 의하면 이미 출생한 자녀의 성구성은 임신결과를 결정하는 가장 중요한 변수로 부각되고 있다. 즉 임신이 인공임신중절로 귀착되는 확률은 부모가 이미 아들을 두고 있는 경우에 일관성 있게 증가되고 있음을 보이고 있다. 따라서 남아선호관은 임신결과를 결정할뿐 아니라 선택절 인공임신중절에 의한 성비의 불균형을 초래하는 주요 변수로써 할거되었다. 특히 피임실천이 보편화되고 선택적 인공임신중절의 이용이 손쉬운 현대사회에 있어서는 남아선호관이 출산력 저하에 저해요인으로서가 아니라, 인위적이던 자연적이던 간에 아들만 두면 단산하는 현행의 출산풍토하에서는 남아선호관이 오히려 출산력저하에 결정적으로 작용하고 있다고 하겠다. 태아의 성 판별을 통한 선택적 인공임신중절의 건수는 1990년 한해에 약 20,000건 정도가 되고, 1986-1990년 사이에 총 80,000건으로 추정된다. 이 수치는 출생한 여아수의 5%에 해당한다. 현재 출생시 성비의 불균형은 연간 총출생수의 10% 미만에 불과한 3번째 이상의 출산에서 발생되고 있기 때문에 인구학적인 측면에서는 큰 문제가 아니다. 그러나 앞으로 출산율의 감소와 더불어 선택적 인공임신중절이 년간 출생수의 90% 이상을 차지하고 있는 둘째, 첫째출산순위로 확산된다면 성비의 불균형은 급진적으로 가속화되어 전통적 결혼관습의 재연등 인간의 생태계를 파괴하는 새로운 차원에서의 사회인구학적인 문제가 야기될 것이다. 결론적으로 성비의 불균형을 초래하는 근본적인 원인은 우리 나라으 전통적인 의식구조인 남아선호관의 상종과 최신의 의료기술에 의한 선택적 인공임신중절에 기인된 것이기 때문에 이를 시정하기 위한 제반 사회제도적 극복정책은 지속적으로 강화되어야 할 것이다.되어야 할 것이다.

• Korean Journal of Environment and Ecology
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• v.12 no.3
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• pp.259-270
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• 1998

This study, as an essential research to develope a mountainous runoff model, was conducted to clarify the hydrologic character and water budget equation of Pinus densiflora and Quercus acutissima. Net rainfall quantity division for two species was investigated at Youngsung experiment forest and Yeungnam University for 30 months(Sep. 1995-Jun. 1998). The results were summarized as follows; 1. The percentages of throughfall and stemflow to gross precipitation are 73.8% and 0.8% in the Pinus densiflora, and 76.9% and 3.8% in the Quercus acutissima, respectively 2. In the Pinus densiflora, regression fomula of stemflow, throughfall, and net rainfall to gross precipitation are S$_{f}$ = 0.01GP-2.05 ($r^2$=0.54) T$_{f}$ = 0.79Gp - 26.04 ($r^2$=0.92), N$_{r}$ = 0.81Gp - 28.09 ($r^2$=0.92). Stemflow and throughfall increased in direct proportion to gross precipitation. 3. In the Quercus acutissima, regression fomula of stemflow, throughfall, and net rainfall to gross precipitation are S$_{f}$ = 0.03Gp + 12.25 ($r^2$=0.74), T$_{f}$ = 0.78Gp + 19.75 ($r^2$=0.96), N$_{r}$ = 0.81Gp + 3199 ($r^2$=0.96), respectively. Comparing with two species, gross precipitation has a much larger effect on the stemflow and throughfall of Quercus acutissima than those of Pinus densiflora. 4. In the analysis of intercorrelation between stemflow and throughfall of each species and crown area(CA), diameter at breast height(DBH), and gross precipitation(Gp), correlation coefficient was higher by following order at each species; Gp>CA>DBH on stemflow of Pinus densinora, Gp>DBH>CA on stemflow of Quercus acutissima, and Gp>CA>DBH on throughfall of Pinus densiflora and Quercus acutissima.ssima.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.366-373
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• 2000

Toxin production and low digestibility of cyanobacteria are known to cause low exploitability of cyanobacteria by zooplankton. In this study, we compared relative tolerance and compatibility of zooplankton taxa in eight eutrophic lakes, exposed to frequent cyanobacterial blooms, uring the summer season of 1999. Microcystis, Anabaena, Oscillatoria and Phormidium were common cyanobacteria in all lakes. with relatively lower $NO_3-N$ concentration (<0.2 mgN/l) and TN/TP ratio (<20), compared with other lakes where colonial cyanobacteria dominated. Rotifers were dominant zooplankton in most lakes, and among them, Keratella, Polyarthra and Hexathra were common. The laboratory feeding experiment showed that relative copepods that greatly decreased (90%) after 4 day when cyanobacteria were used as the food source of zooplankton, while rotifers gradually increased with the change of dominant taxa from Keratella through Pompholyx to Monostyla. These results suggest that rotifers may be capable of coexisting with cyanobacteria by exploiting them for the food source.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.29-45
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• 2017

This study explored spatiotemporal variability of water quality in correspondence with hydro-meteorological factors in the four stations of Euiam Reservoir located in the upstream region of the North-Han River from May 2012 to December 2015. Seasonal effect was apparent in the variation of water temperature, DO, electric conductivity and TSS during the study period. Stratification in the water column was observed in the near dam site every year and vanished between August and October. Increase of nitrogen nutrients was observed when inflowing discharge was low, while phosphorus increase was distinct both during the early season with increase of inflowing discharge and the period of severe draught persistent. Duration persisting high concentration of Chl-a (>$25mg\;m^{-3}$: the eutrophic status criterion, OECD, 1982) was 1~2 months of the whole year in 2014~2015, while it was almost 4 months in 2013. Water quality of Euiam Reservoir appeared to be affected basically by geomorphology and source of pollutants, such as longitudinally linked instream islands and Aggregate Island, inflowing urban stream, and wastewater treatment plant discharge. While inflowing discharge from the dams upstream and outflow pattern causing water level change seem to largely govern the variability of water quality in this particular system. In the process of spatiotemporal water quality change, factors related to climate (e.g. flood, typhoon, abruptly high rainfall, scorching heat of summer), hydrology (amount of flow and water level) might be attributed to water pulse, dilution, backflow, uptake, and sedimentation. This study showed that change of water quality in Euiam Reservoir was very dynamic and suggested that its effect could be delivered to downstream (Cheongpyeong and Paldang Reservoirs) through year-round discharge for hydropower generation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.203-216
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• 2008

This study was conducted to provide the fundamental data based on the analysis of phsyco-chemical characteristics of domestic aroma rice and foreign aroma rice for breeding of aroma rice. The average amylose content of domestic aroma rice and widely cultured domestic traditional rice were 18.1% and 19.0% respectively. The Indica and the Japonica types were 25.6% and 25.0%. In the domestic rice of Tongil and Japonica type, the average protein content were 7.6% and 6.4% respectively. And the average protein content of foreign Indica and Japonica type were 7.6% and 7.0% respectively. And the average protein content of widely cultured domestic traditional rice was 5.6%. The Japonica type of rice shown a low protein content compared with Indica type of rice, and the foreign Indica types of rice exhibited a wide range of protein contents. The average alkali digestive value (ADV) of Tongil type of the domestic aroma rice was about 5.0 and the value of Japonica type was about 6.0. The average ADV of foreign Indica and Japonica type were 4.3 and 5.1 respectively. Also the average ADV of widely cultured domestic aroma rice was about 6.0. The foreign aroma rice were distributed a variable range of ADV value and lower than the both domestic aroma rice and widely cultivated domestic rice. In the whole aspect of the amylogram, the highest viscosity, the lowest viscosity and the last viscosity of the total resources, in domestic aroma rice were clearly lower with the next order, Japonica type of foreign aroma rice, Indica type of foreign aroma rice, Japonica type of domestic aroma rice, widely cultured domestic traditional rice, and Tongil type of domestic aroma rice. It shown the difference aspect of amylograms according to the eco-type of the domestic and foreign aroma and the general rice, and it was distinguishable in difference of the aspect of the amylogram of the endosperm of rice as non-glutinous rice, waxy rice, and middle-waxy rice.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.124-138
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• 2003

This paper aimed to analyze the relationship between alga3 bloom patterns and hydrological, limnological data which were collected from major reservoirs in Korea for 8 years (1990${\sim}$1997). Water temperature of river-type reservoirs showed wider seasonal fluctuations than that of lake-type. pH of lake-type reservoirs was low in winter season but high in summer season. In contrast, river-type reservoirs showed high pH in spring and autumn seasons as well, and very low in summer season. COD of lake-type reservoirs and Paldang reservoir was lower (2${\sim}$3 mg/L) than that of Geumgang and Nagdonggang reservoirs (6${\sim}$9 mg/L). Dissolved oxygen (DO) of river-type reservoirs was higher than that of lake-type reservoirs. Seasonal fluctuation pattern of DO saturation in river-type reservoirs was high (80 ${\sim}$100%) and remained relatively constant whereas lake-type reservoirs showed the highest level (93%) in late spring or early summer, which gradually decreased entering winter season(46${\sim}$06%). And monthly variation of DO saturation showed inverse proportion to water volume in lake-type reservoirs. Nutrients concentration in river-type lake is higher than lake-type. Seasonal fluctuation of nutrients (T-N, T-P) in lake-type reservoirs was relatively small than that of river-type reservoirs. Annual mean N/P mass ratio of lake-type reservoirs was higher than that of river-type. Transparency tended to related with the suspended solid concentration in river-type reservoirs. Algal bloom of lake-type and river-type reservoirs occurred at any time except rainfall and winter periods. And it dominated in summer and early autumn, respectively. Algal bloom of river-type reservoirs was higher than that of lake-type. Relationship between rainfall and chlorophyll- a in lake-type reservoirs was relatively high, however river-type reservoirs showed insignificant.