• Title/Summary/Keyword: community variation

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Spatial-temporal Variation of Fouling Organisms Recruited on a Fishing Net based on Community Structure, Tongyeong, Southern Coast of Korea (통영 연안 가두리 양식용 그물에 가입되는 오손생물군집의 시·공간적 비교)

  • Kim, Hyuk-Jin;Yoon, Kon-Tak;Park, Heung-Sik
    • Ocean and Polar Research
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    • v.43 no.4
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    • pp.255-267
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    • 2021
  • To understand the composition and community changes of benthic species by water depth (5 m, 20 m, 30 m) in the cage facilities, net substrate made of fish cages were installed at intervals of 2 months from March to September 2019, which is the main period of sessile organism recruitment. Water temperature and salinity varied in the ranges of 1~5℃ and 1~4 mg/L at 5 m from June to August, respectively, and less difference was observed according to water depth in other investigation periods. A total of 37 benthic animals were recruited, and Kamptozoa unid., Caprella scaura and Jassa slatteryi were verified during the entire study period. Mytilus galloprovincialis, a Mediterranean mussel, showed seasonality dominant only from spring to early summer (March to July). The community structure classified by temporal and spatial factors, and Bugula neritina, Kamptozoa unid., and Sertularella sp. contributed to the formation of the community. The depth of 5 m was exposed to environmental changes in water temperature and salinity temporally, so there was a seasonal variation in the composition of the sessile organism, but at depths of 20 m and 30 m, there was less significant environmental change and it showed relatively stable than 5 m.

Developing Dish-based Food Frequency Questionnaire for the Epidemiology Study of Hypertension Among Korean (고혈압 역학연구를 위한 음식중심 식품섭취빈도 조사표 개발: 2001년 국민건강영양조사 자료 이용)

  • Kim, Mi-Kyung;Yun, Young-Mi;Kim, Young-Ok
    • Korean Journal of Community Nutrition
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    • v.13 no.5
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    • pp.701-712
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    • 2008
  • The purpose of the present study was aimed to identify dish items applicable in developing dish?based food frequency questionnaire (DFFQ) for a hypertension study of Koreans. The 24-hour recall data of 4,401 subjects aged $20{\sim}65$ years from the 2001 Korean National Health and Nutrition Examination Survey were used for the analysis. Logistic regression model was used to identify the nutrient related with hypertension. Energy, fiber, sodium, calcium, carotene, vitamin B1 and vitamin C were associated with hypertension. Selection the top 30 dish items for these seven nutrients was performed based on their degree of contribution in supplying nutrients in terms of the cumulative percent contribution (cPC), as well as on their degree of explanation for between?person variation, in terms of the cumulative regression coefficient (cMRC). Rice supplied 43% of total energy consumption. Korean cabbage and radish kimchi were two major sources of sodium and it also covered the 27% of between person variation of sodium intake. Soybean paste soup and single item of orange?colored fruits supplied 43% of total vitamin C intake for Koreans and it covered the almost 79% of between person variation among the Korean population. Korean cabbage kimchi was the major source of fiber, calcium, sodium, carotene, and vitamin C for Koreans. In summary, the top 30 selected dish items supplying the 78% to 89% of the 7 nutrients. Those items also covered the 79% to 94% of between person variation of the 7 nutrients consumption. Therefore, the selected 30 dish items in each categories of nutrient could be applicable in developing dish based food frequency questionnaire for hypertension study.

Structure and Dynamics of Abies koreana Wilson Community in Mt. Gaya (가야산 구상나무 군락의 구조 및 동태)

  • Lee, Chang-Seok;Hyun-Je Cho
    • The Korean Journal of Ecology
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    • v.16 no.1
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    • pp.75-91
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    • 1993
  • Structure and dynamics of Abies koreana community in Mt. Gaya were studied to provide the basic data for conservation of Abies koreana community, an endemic species in Korea. A. koreana community of this study site was composed of tree layer (4~7m), subtree layer (2~4m), shrub layer (1~2m), and herb layer (below 1m). The heights of tree and subtree layers were low. Floristic composition showed that this study site was subalpine and dry site. In frequency distribution diagram of diameter classes of major species consisting of A. koreana community, those of both A. koreana and other species showed reverse J-shaped types. From these results, it was estimated that A. koreana community of this site might be maintained continuously as a stable climax state like present state. In the spatal distribution diagram of major species, saplings of A. koreana were established under the canopy of A. koreana and Pinus koraiensis and under the dead tree of A. koreana. From these results, it was known that A. koreana saplings were recruited before the community was disturbed and regeneration was accomplished by advance regeneration pattern, in which these saplings established before occurrence of disturbance fill with open site originated from death of mature tree. Growth of annual rings was variable among individuals, it was estimated that such variation was originated in that growth of each individual relates to microclimatic conditions rather than macroclimatic ones. Ecological longevity of A. koreana in this study site estimated by disturbance types and age of dead trees was about 120 years.

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Cyclic Change of Phytoplankton Community in Mankyeong River Estuary prior to the Completion of the Saemankeum Seawall (새만금 방조제 완공 이전 만경강 하구역 식물플랑크톤 군집의 주기적인 변동)

  • Kim, Young-Geel;Park, Jong-Woo;Jang, Keon-Gang;Yih, Won-Ho
    • Ocean and Polar Research
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    • v.31 no.1
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    • pp.63-70
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    • 2009
  • Eutrophicated water fed through Mankyeong River and Dongjin River into the new Saemankeum Lakemight seriously affect the water quality and phytoplankton community in the lake. To obtain control reference data for the later studies on environmental changes due to the construction of the Saemankeum Sea Wall, we performed a monthly investigation on the physico-chemical properties of the water and phytoplankton community at 3 stations in the Mankyeong River Estuary over 14 months starting from September 1999. Water temperature ranged from $0.3{\sim}32.9^{\circ}C$ due to the typical seasonal variations in temperate on the coasts and salinity exhibited a wide annual range of $0.2{\sim}33.7$ psu along with regular and huge hourly variations according to tidal cycles. Inorganic nutrients were supplied from rivers to the monitoring station and the whole lake. The average concentration of total-N, $6.99\;mg{\cdot}l^{-1}$, was higher than the water quality for agricultural use with peak values occurring in winter. Species composition showed a seasonal succession pattern, where a high diversity was observedin summer and autumn and vice versa in winter. Hourly variations of water properties in the "Mankyeong bridge" Station were quite regular and well in accordance with the daily tidal cycles. The different degree of sea water intrusion during the flood tide at each of the 3 stations exhibited a different range and variation pattern of water temperature and salinity throughout a day. Hourly changes in species composition were in harmony with the daily tidal cycles, resulting in extremely variable spatio-temporal variation.

Studies on the Fauna of the Soil Microarthropods in Forest Floor (산림토양의 절지 동물상에 관한 연구)

  • Woo, K.S.;Choo, H.Y.;Chung, K.
    • Korean journal of applied entomology
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    • v.26 no.3 s.72
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    • pp.133-138
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    • 1987
  • This study was conducted during Oct. 1986$\sim$Apr. 1987 to investigate the distribution, dominance and species diversity of soil arthropods communities from two collection sites of Suwon and Mt. Jiri. A total of 2,989 specimens of 3 orders, 20 families and 19 species were identified. In overall dominance index, Suwon community showed lower value than Mt. Jiri community. Seasonal variation dominance index were higher in Suwon community than those in Mt. Jiri community.

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Analysis on Regional Variation in Educational Community Formation of Rural Village - Case Analysis of Songak in Asan-si, Chungcheongnam-do - (농촌마을교육공동체 형성과정에서 나타나는 지역의 변화 분석 - 충남 아산시 송악지역 사례를 중심으로 -)

  • Ko, Kyung-Ho
    • Korean Journal of Organic Agriculture
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    • v.27 no.3
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    • pp.307-325
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    • 2019
  • This study aims to analyze the regional variations in which appear during the formation process of educational community in rural villages from the perspective of regional innovation theory. The study results revealed that the activities to form an educational community of the Songak village significantly influenced the variations across the social, economic and environmental aspects beyond an innovation of public education within the region based on interrelation between schools and villages. In other words, the activities including interactions and group learnings have been actively promoted among the various relevant stakeholders, thereby resulting in a variety of positive variations such as expanded regional welfare base, activated voluntary residents community gatherings based on the unity and cooperation, broadened socioeconomic opportunities, satisfaction on educational and cultural desires, and construction of healthy ecological environment in the region. Therefore, it is thought that regional development policy suitable for each region needs to be established by embracing the fact that activities to form a village educational community entail significant implication and value as the comprehensive regional innovation activities across the entire domains in each region.