• Ocean and Polar Research
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• v.29 no.2
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• pp.101-112
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• 2007

In order to examine the short-term variations of phytoplankton and heterotrophic protozoa community structures with bloom events, water samples were collected every other day at one site in the coastal water off Incheon, Korea, from August 15-September 30, 2001. $Chlorophyll-{\alpha}$ concentrations varied widely from 1.8 to $19.3\;{\mu}g\;l^{-1}$ with the appearances of two major peaks of $Chlorophyll-{\alpha}$ concentration during the study period. Size-fractionated $Chlorophyll-{\alpha}$ concentration showed that net-size fraction ($>20\;{\mu}m$) comprised over 80% of total $Chlorophyll-{\alpha}$ during the first and second bloom periods, nano-size fraction ($3{\sim}20\;{\mu}m$) comprised average 42% during the pre- (before the first bloom) and post-bloom periods (after the second bloom), and pico- size fraction ($<3\;{\mu}m$) comprised over 50% during inter-bloom periods (i.e. between the first and second bloom periods). Dominant phytoplankton community was shifted from autotrophic nanoflagellates to diatom, diatom to picophytoplankton, picophytoplankton to diatom, and then diatom to autotrophic nanoflagellates, during the pre-, the first, the inter, the second, and the post-bloom periods, respectively. During the blooms, Chaetoceros pseudocrinitus and Eucampia zodiacus were dominant diatom species composed with more than 50% of total diatom. Carbon biomass of heterotrophic protozoa ranged from 8.2 to $117.8\;{\mu}gC\;l^{-1}$ and showed the highest biomass soon after the peak of the first and second blooms. The relative contribution of each group of the heterotrophic protozoa showed differences between the bloom period and other periods. Ciliates and HDF were dominant during the first and second bloom periods, with a contribution of more than 80% of the heterotrophic protozoan carbon biomass. Especially, different species of HDF, thecate and athecate HDF, were dominant during the first and the second bloom periods, respectively. Interestingly, Noctiluca scintillans appeared to be one of the key organisms to extinguish the first bloom. Therefore, our study suggests that heterotrophic protozoa could be a key player to control the phytoplankton community structure and biomass during the study period.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.339-347
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• 2015

Differences in characteristics of flora and environmental factors of geomorphology, hydrology, water quality and soil were investigated in the shoreline of total 35 reservoirs according to their usages of waterpower generation, agricultural water supply, residential and industrial water supply and flood control in Korea. The number of plant species, floral structure and characteristics of species traits in the shoreline of reservoirs were different according to their usage. From the results of stepwise regression analysis, the total number of vascular plant species was increased at the environment of the higher flood frequency at the median water level and the longer exposure duration of the shoreline. The results of principal coordinates analysis and cluster analysis showed that the shoreline flora was classified as the 3 types of 1) flood control and residential and industrial water supply, 2) agricultural water supply and 3) waterpower generation reservoirs. The water level fluctuation, flood frequency at the median water level, lake water quality index and exposure duration of the shoreline were selected as important environmental factors affected on the characteristics of shoreline flora. The species richness of total flora and hydrophytes, especially submerged macrophytes, were much higher in the reservoirs for the purpose of the waterpower generation in which mesotrophic water quality and stable water levels were maintained. Annual or biennial ruderals were established on the ephemeral drawdown zone of flood control, residential and industrial water supply reservoirs which have oligotrophic or mesotrophic water quality and wide range of water level fluctuation. The floating hydrophytes were differentially dominated in the littoral zones of the agricultural water supply reservoirs with a mesotrophic or eutrophic water quality and a medium water level fluctuation. In conclusion environmental factors related to water level fluctuation and water quality were different and then the floral characteristics of shoreline were distinguishable according to usage of Korean reservoirs.

• Plant Disease and Agriculture
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• v.2 no.1
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• pp.50-60
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• 1996

최근에 농업기술의 발달로 작물의 재배환경과 재배기술 또한 날로 개선되어 가고 있으나 농촌 인력의 부족과 재배자의 고령화로 인한 토양 비배 관리의 소홀, 화학 비료의 과다 및 편중 사용, 토양 산도 변화에 따른 작물의 영양 흡수 불균형으로 인한 생리적 장해의 발생과 하우스 재배면적의 증가로 인한 연작장해의 발생이 심각한 문제로 대두되고 있다. 본 강좌에서는 지난 호의$\mathbb{\ulcorner}$영양생리 장해의 발생현황과 발생조건$\mathbb{\lrcorner}$에 이어 작물재배시에 발생하는 각종$\mathbb{\ulcorner}$영양생리 장해의 진단$\mathbb{\lrcorner}$방법을 소개한다.

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.77-77
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• 2018

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.88-88
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• 2018

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.04a
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• pp.110-110
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• 2019

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.04a
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• pp.111-111
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• 2019

• The Korean Journal of Ecology
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• v.23 no.3
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• pp.255-266
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• 2000

생물권보전지역으로 지정된 점봉산의 온대낙엽수림(참나무 성숙림)에서 임상초본식물의 공간분포를 정량화하고, 이들의 공간분포에 미치는 미소환경요인의 영향을 파악하였다. 대부분의 임상초본식물들은 영구 방형구내 미소지소간에 큰 변이를 나타내었다. 초봄에 출현하는 임상초본식물중 공간의존도가 높은 식물은 현호색, 애기나리 및 노랑제비꽃이었고, 가을에 출현하는 임상초본식물중 공간의존도가 높은 식물은 벌깨덩굴, 쌀새 및 도라지모시대이었다. 초봄에 출현하는 홀아비바람꽃과 얼레지 그리고 가을에 출현하는 도라지모시대와 쌀새의 공간의존거리가 상대적으로 짧은 편이었다. 초봄에 출현하는 노랑제비꽃, 애기나리 및 얼레지는 관목이 적고, 낙엽층이 얇으며,토심이 깊고, 토양수분함량, 유기물함량 및 염기성양이온함량이 상대적으로 적은 생육지를 선호하였고, 애기앉은부채 와 현호색은 관목이 밀집하고, 낙엽층이 두꺼우며, 토심이 얇고, 유기물함량, 토양수분함량 및 영양염류함량이 높은 생육지를 선호하였다. 오리방풀은 빛조건이 좋고, 낙엽층이 두꺼우며, 토양수분함량과 영양염류가 풍부한 생육지를 선호하였고, 단풍취, 대사초, 개별꽃, 참취, 쌀새 및 도라지모시대는 토심이 깊고, 낙엽층이 얇으며, 토양수분함량과 영양염류함량이 상대적으로 적은 생육지를 선호하였다. 본 참나무 성숙림에서 토양수분함량, 유기물함량 및 영양염류함량은 바람, 미소지형 및 관목의 밀집정도에 의해 공간적으로 재배치되는 낙엽층 두께에 의해 영향을 받고 있기 때문에 초봄과 가을에 관찰되는 임상초본식물의 공간분포는 낙엽층의 불균등한 분포에 의해 가장 큰 영향을 받고 있는 것으로 추정되었다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.64-64
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• 2022

서리이끼속(Racomitrium Brid.)은 고깔바위이끼과(Grimmiaceae)에 속하며 전 세계에 약 80여종이 알려져 있다. 이 중 한국산 서리이끼속은 18종이 보고되어 있으며, 그 중 6종은 1900년대 초반 한반도에서 최초 발견되어 신종으로 보고되었다. 서리이끼속 이끼류는 주로 양지바른 바위나 사질토양 등에 서식하고, 건조에 강한 것으로 알려져 있다. 원예·조경 분야에서 실내 벽면 및 옥상 녹화용 자원식물로 서리이끼속은 주로 늦은서리이끼(Racomitrium japonicum)와 모래이끼(Racomitrium canescens)가 활용되고 있다. 국내에서도 자원식물로써 선태류에 대한 관심이 증대함에 따라 자생 선태류에 대한 형태적 특징과 함께 생육환경에 대한 정보 제공 요구 또한 증가하고 있다. 이에, 본 연구는 자원식물로 활용이 가능한 한반도산 서리이끼속의 형태·생태적 특징을 파악하고자 하였으며, 기준표본 원산지가 한반도인 서리이끼속 6종을 우선하여 서식 환경 특징을 파악하고자 한다.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.83-94
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• 2024

The proportion of plant-based meat alternative (PBMA) consumers has recently increased in Korea. This is due to several reasons including protecting the environment, satisfying preferences, maintaining health, and improving eating habits. Accordingly, many companies produce and sell alternative meat using various materials. Alternative meats are classified into plant (such as soybeans and wheat), seaweed, insect, and cultured meats, depending on the raw materials used in manufacturing. PBMA is sold after undergoing processes such as grinding, seasoning, and molding. Therefore, monitoring the presence of any hazardous elements during this process is essential. Accordingly, in this study, we analyzed the harmful components of nine domestically distributed PBMA that are most easily accessible to consumers. After extracting fat from the samples and analyzing the rancidity level, samples F, G, and I were highly rancid. Trace amounts of aflatoxin were detected in samples A and B, but confirmed to be within the range. Cd and Pb were not detected in any sample. We hope that this study will help establish methods to ensure the safety of domestically sold PBMA.