• Korean Journal of Environment and Ecology
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• v.11 no.4
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• pp.433-449
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• 1998

To study the plant community structure of Chayang-chon area from Jangsudae to Hangyeryung in Soraksan National Park, 62 plots(each size 100m$^2$) were set up and surveyed. Six communities(Pinus densiflora - Populus caximowiczii community, P. densiflora community, P. densiflora - Deciduous broad-leaved tree community, Quercus mongolica community, Q. mongolica - Carpinus cordata community, C. cordata - Deciduous broad- leaved tree community) were classified by DCA ordination techniques. Q. mongolica community, Q. mongolica - C. cordata and C. cordata - Deciduous broad-leaved tree community were distrivuted over altitude 755m, and the others were distributed below there. In the community over altitude 755m, the succession that Q. mongolica community changed to C. cordata community have proceeded partly and otherwise C. cordata community and Deciduous broad-leaved tree community have been competing with each other. In the community with distribytion range from 500m to 560, high, P. densiflora community would change deciduous broad-leaved tree community forward.

• Korean Journal of Environment and Ecology
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• v.22 no.6
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• pp.648-657
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• 2008

This research was conducted to investigate the breeding density and seasonal food items of the magpies in Jeju Island and the near-manned islets. The examination of nest distribution to determine breeding density was performed during breeding season from February 2006 to April 2008, and that of food items from May 2006 to February 2008. A total of 2,113 nests were found across Jeju Island, the average density was $1.33\;nest/km^2$, and the magpies were distributed up to 600 meters above the sea level. The nest density was the highest in the central areas of Jeju Island, with 688 nests at $3.61\;nest/km^2$, while that in the eastern areas was the lowest, with 214 nests at $0.66\;nest/km^2$. In terms of the number of nests depending on the height above the sea level, 1,172 nests, which was equivalent to the density of $1.85\;nest/km^2$, was observed below 100m and highest among the intervals of height, but 16 nests found at 500-600m were the lowest, corresponding to $0.20\;nest/km^2$. The number of nests found in the manned islets near Jeju Island was eight in Biyang-do with the density of $15.38\;nest/km^2$, nine in U-do with $1.49\;nest/km^2$, and one in Gapa-do with $1.15\;nest/km^2$, whereas none of nests were observed in Mara-do. The contents of stomach consisted of 17 types of prey sources including countless bones, eggshells, plants, and seed, most of which were the individuals of the order Coleoptera. In spring and summer, the foraging frequency for invertebrate animals such as insects was high, but less than 30% in winter. In contrast, the magpies preyed upon plants and seeds at the frequency of 10% and 30%, respectively, in spring, while the foraging frequencies for both of them were 100% in winter and higher than any of other seasons. Eggshells and bones of birds were also detected infrequently. If the density of the magpies, which may play role as the upper predator within the ecosystem, increases, it would be expected to affect directly the reduction of the number of the species and population of endemic animals such as small birds and reptiles, etc. Therefore, it is considered that long-term monitoring for the density of the magpies and precaution is prerequisite to minimize adverse effects on ecosystem.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.14 no.1
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• pp.15-36
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• 1978

Underwater sounds of some fishes and crabs were analyzed in the laboratory. The behavioral responses to the playback sounds of their feeding and croaking sound were investigated. The samples used in the experiment were as follows: Nibea albiflora, seriola quinqueradiata, Navodon modestus, Fugu xanthopterus, chrysophrys major, Scylla serrata, Telmessus acutidens, Charybdis japonica, and Portunus trituberculatus. The feeding and croaking sounds of the samples were recorded by a tape recorder through a hydrophone in an anechoic aquarium. The sound intensity level was measured by means of a sound level meter at an anechoic chamber. The frequency, intensity and wave form of various sounds were analyzed with an analyzing system consisting of a 1/3 octave filter set, a high speed level recorder, an amplifier, an octave band analyzer and an oscilloscope. The most successful recording was edited into a sequence of sound track which repeats sound emitting for 5 to 7 seconds after pausing for 5 to 7 seconds. The sequence was then reproduced into an anechoic aquarium through the under water speaker. The experimental anechoic aquarium used for the sample fishes was divided into the four sections with any three screens selected from 40$\times$40mm, 60$\times$60mm, 80$\times$80mm and 100$\times$100mm mushes according to the species of the fishes, besides that for crabs were not sectioned. The results of the investigation are as follows: 1. Of the feeding sound of fish, the frequency of wave from of the sound produced by Nibea albiflora and seriola quinqucradiata was 125～250Hz, that by Navodon modestus 63～125Hz, and that by Fugu xanthopterus 400～500Hz. The pressure level of the feeding sound produced by Nibea albiflora and Seriola quinqueradiata was 56～62db, that by Navodon modestus 57～59db, and that by Fugu xanthopterus 60～64db. 2. Of the croaking sound of Nibea albiflora, the frequency of the sound was 125～250Hz almost equivalent to that of feeding sound, and the pressure level was 62～63db, slightly higher than that of feeding sound. 3. Of the croaking sounds of crabs, the frequency of the sound produced by scylla serrata was 125～250Hz, that by Charybdis japonica and Telmessus acutidens 500～1,000Hz, and that by Portunus trituberculatus 250～500Hz. The pressure level of the croaking sound by Scylla serrata was 68～70db, and that by Charybdis japonica, Telmessus acutidens and Portuens trituberculatus 50～62db. 4. Phonotactic responses of Nibea albiflora and Seriola quinqueradiata to the feeding sounds produced by their own species, the same body length were conspicuous with the phonotactic index of 56～87%, but that of Navodon modestus, Chrysophrys major and Fugu xanthopterus were hardly recognized. 5. Phonotactic responses of the sample fishes to the sinusoidal sound with the frequency range of 50 to 9,000 Hz were observed not conspicuous. 6. Phonotactic responses of Portunus trituberculatus to the croaking sounds produced by their own species was varied in the range of 40～100%, according to the carapace length and the sex.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.624-635
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• 2019

Bird strike accidents, a collision between aircraft and birds, have been increasing annually due to an increasing number of aircraft operating each year to meet heavier demand for air traffic. As such, many airports have conducted studies to assess and manage bird strike risks effectively by identifying and ranking bird species that can damage aircraft based on the bird strike records. This study was intended to investigate the bird species that were likely to threaten aircraft and compare and discuss the risk of each species estimated by the single-matrix and multi-matrix risk assessment models based on the Integrated Flight Information Service (IFIS) data collected in Gimpo, Gimhae and Jeju Airports in South Korea from 2005 to 2013. We found that there was a difference in the assessment results between the two models. The single-matrix model estimated 2 species and 6 taxa in Gimpo and Gimhae Airports and 2 species and 5 taxa in Jeju Airport to have the risk score above "high," whereas the multi-matrix model estimated 3 species and 5 taxa in Gimpo Airport, 4 species and 5 taxa in Gimhae Airport, and 2 species and 3 taxa in Jeju Airport to have the risk score above "very high." Although both models estimated the similar high-risk species in Gimpo and Gimhae Airports, there was a significant difference in Jeju Airport. Gimpo and Gimhae Airports are near the estuary of a river, which is an excellent habitat for large and heavy waterbirds. On the other hand, Jeju Airport is near the coast and the city center, and small and light bird species are mostly observed. Since collisions with such species have little effect on aircraft fuselage, the impact of common variables between the two models was small, and the additional variables caused a significant difference between the estimation by the two models.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.452-454
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• 2000

While magpies are making their nest and are laying eggs from February to May time frame, the electrical power incidents by magpies are as high as 30% of all. This research will examine the establishment of frequency of magpies by utilizing Alarm Calls with their own voice characteristic and also try avoiding access to distribution equipments in order to prevent from constructing their nests on the distribution lines. This research results contribute to improve the reliability in the power distribution line.

• Korean Journal of Environment and Ecology
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• v.13 no.3
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• pp.244-253
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• 1999

백운산의 산림군락과 환경 요인과의 관계를 구명하기 위하여 TWINSPAN과 CCA Ordination을 이용분석한 결과는 다음과 같다. TWINSPAN에 의해서 서어나무 군락, 고로쇠나무 군락, 신갈나무 군락 및 굴참나무 군락의 4 group으로 구분되었다. 주요 군락과 환경 용인과의 상관을 보면 서어나무 군락과 굴참나무 군락은 해발고가 중간이고 유기물 함량과 유효인산의 양료가 중간인 곳에 주로 분포하고 신갈나무 군락은 해발고가 높고 유기물 함량과 유효인산의 양료가 많은 곳에 주로 분포하며 고로쇠나무 군락은 해발고가 낮고 $K+$,$Ca{++}$,및 $Mg^{++}$등의 양료가 많은 곳에 주로 분포하고 있다 주요 수종과 환경과의 상관관계를 보면 해발고가 높고 유기물 함량과 $P_2O_5$ 많은 곳에 신갈나무, 노리재나무, 물푸레나무, 해발고가 중간기고 양료가 중간인 곳에 서어나무, 비목, 단당풍 졸참나무, 쪽동백나무, 때죽나무, 해발고가 낮고, 습하며$K+$,$Ca{++}$,및 $Mg^{++}$ 등의 양료가 많은 계곡부타 까치박달나무 층층나무, 느티나무, 고로쇠나무, 들메나무, 나도밤나무 및 산뽕나무가 분포하고 있다.

• The Korean Journal of Ecology
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• v.20 no.3
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• pp.175-179
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• 1997

To explanin allopatric distribution of Carpinus cordata and C. laxiflora in the field the effect of soil flooding on photosynthesis and water relations was tested with field grown saplings. Under the flooding condition stomatal conductance of C. laxiflora decreased markedly from day two after flooding treatment and remanined low throughout the experiment. In contrast, flooding had no effect on stomatal conductance of C. cordata throughout the exper iment. The rate of photosynthesis of C. laxiflora was significantly suppressed under flooding conditions, whereas that of C. cordata was not affected in the flooded condition. On day seven after flooding treatment xylem pressure potential of C. laxiflora significantly decreased. Flooding, however, did not have any effect on the xylem pressure potential of C. cordata throughout the experiment. From these findings it is concluded that there is a difference in resistance to flooding between C. cordata and C. laxiflora and that one of the the factors responsible for allopatric distribution in the two species is flooding.

• Korean Journal of Environment and Ecology
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• v.13 no.2
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• pp.143-152
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• 1999

전북 장안산의 신갈나무림을 분류법과 서열법에 의하여 분석하였다. 분류법(식물사회학적 방법)에 의한 신갈나무림의 분석결과 신갈나무-철쭉꽃군락, 신갈나무-노린재나무군락, 신갈나무-조릿대군락의 3개 군락으로 분류되었다. CCA에 의하여 분석된 결과에 의하면 신갈나무, 철쭉꽃, 노린재나무는 고도가 높은 지역에서 분포하고, 고로쇠나무, 들메나무, 고광나무, 함박꽃나무, 까치박달은 습하고 유기물 함량 및 전질소, C.E.C등의 양료가 양호한 지역에 소나무, 굴참나무, 붉나무, 병꽃나무는 고도가 낮은 지역에서 분포하고 있다. 신갈나무림의 분포와 환경과의 상호관계를 분석한 결과 고도, 토양습도, 유기물함량, 지형, pH등이 높은 상관관계를 나타냈다.

• Proceedings of the KIEE Conference
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• 2005.11c
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• pp.87-89
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• 2005

Most of electrical service outage in overhead distribution lines are due to the magpies. The magpies make the short circuit in building up there nests and the grounding fault in directly contacting with the energized conductors. This paper described the performance of the existing anti-magpie devices to prevent the fault due to birds in distribution lines the reaction tests for the magpies were carried out for the sensors to simulate them in there territory.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.404-411
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• 2019

This study was carried out to investigate the antioxidant effects of extracts from 9 species of forest plants in Korea. DPPH, ABTS, $NaNO_2$, hydrogen peroxide radical scavenging activity and reducing power activity were evaluated to measure the antioxidant activities of plant extracts. As a result, Geranium thunbergii has been identified as the most effective antioxidant resource. Also, total phenolic content was highest in Geranium thunbergii ($303.94{\pm}0.63mg\;GAE/g$) among 9 species extracts. Total flavonoid content was highest in Rosa multiflora ($24.32{\pm}0.22mg\;QE/g$) and proanthocyanidin content was highest in Vitis ficifolia ($279.00{\pm}4.58mg\;CE/g$) among 9 species extracts. In addition, the protective effect of plant extracts in $H_2O_2-induced$ human dermal fibroblast (HDF) cell systems were also assessed. Significant protective effects in $H_2O_2-induced$ human dermal fibroblast (HDF) cell systems were found in all plant extracts, especially in Geranium thunbergii. These results suggest that Geranium thunbergii could be a potential natural resource for antioxidant activity.