• ALGAE
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• 제19권4호
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• pp.321-327
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• 2004

The literature review on the dynamics of the phytoplankton communities in terms of species composition, standing crops, abundant species and dominant species in the lower part of the Han River from 1940s to 2000s was conducted for the prospective prediction of their succession patterns. Total of 326 taxa were identified and they belonged to 47 blue-green algae, 139 green algae, 12 euglenoids, 126 diatoms, 6 din flagellates and 2 silicoflagellates. Composition of phytoplankton communities were 83.6% diatoms, 10.5% blue-green algae and 5.3% green algae in the middle of 1960s, whereas those were 43.2% diatoms, 40.7% green algae and 13.6% blue-green algae in the 1990s. Before 1990s, Synedra ulna, Melosira varians, Cymbella tumida, Synedra acus, Cymbella ventricosa, Navicula cryptocephala, Nitzschia palea, Aulacoseira granulata, Gomphonema parvulum and Cymbella affinis were most frequent, while those after 1990 were Asterionella formosa, Asterionella gracillima, Aulacoseira granulate, Aulacoseira granulata var. angustissima, Chlorella vulgare, Fragilaria crotonensis and Synedra ulna. Phytoplankton blooms were frequent from winter to the late spring and rare in summer due to heavy rain and discharge. Seasonal variations of the dominant species were fairly obvious; Asterionella gracillima and Aulacoseira granulata in spring, Aulacoseira granulate and Aulacoseira granulate var. angustissima in summer and autumn, Asterionella gracillima and Stephan discus hantzschii in winter. Recently blue-green algae, Microcystis, Aphanocapsa, Dactylococcopsis have been more abundant than those of the previous reports. Based on the current situations, Stephan discus hantzschii f. tennis, Asterionella gracillima, Aulacoseira granulate and blue-green algae will be more abundant and blooms of those species will be more frequent.

• ALGAE
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• 제19권4호
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• pp.329-337
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• 2004

Monthly variations of phytoplankton communities were conducted to the investigation at five stations in mid and lower parts of the Nakdong River from December 1995 to November 1996. The phytoplankton communities were identified a total 456taxa which were composed of 136 genera, 427 species, 27 varieties and 2 forma. The standing crops of phytoplankton communities ranged from 2.7 to 52.8 (${\times}$10³)cells·ml$^{-1}$ during the investigation periods. Bacillariophyceae was the dominant classes at all stations. The dominant species were 7taxa and the standing crops of these ranged from 18.3 to 95.1% of the standing crops of phytoplankton communities. The dominant species in the mid parts (st. 1, 2) of this river system were benthic species such as Navicula gregaria, N. viridula var. rostellata and Nitzschia palea, however it was planktonic species (Stephan discus hantzschii, Golenkinia radiata) and meroplanktonic species (Aulacoseira ambigua, A. granulata) in the lower parts (st. 3, 4, 5). The seasonal variations of the dominant species in the lower parts were appeared to the planktonic species (S. hantzschii) from winter to spring, and were the meroplanktonic species (A. ambigua and A. granulata) in from summer to fall. The lower parts of the Nakdong river were entropic states because the dominant species were composed A. ambigua, A. granulate and S. hantzschii which were indicators of entropic water quality. The interrelationships between total standing crops and environmental factors(water temperature, pH, NH$_4$, NO$_2$, NO$_3$ and PO$_4$) were low positive or negative coefficients. S. hantzschii had low positive or negative relations with water temperature, NH$_4$, NO$_2$, NO$_3$ and PO$_4$. As the result, the variations of standing crops of phytoplankton were not caused by a single factor but controlled by the complex factors.

• 한국환경농학회지
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• 제26권1호
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• pp.7-16
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• 2007

The objective of this research was to review the correlation between microalgae and agricultural water quality. Although microalgae has been considered as an essential factor for control1ing of water ecosystem, little attention has been paid for evaluating of microalgae as an important factor for water quality management. But it can be use to make us know the water pollution state at saprobic system, LTSI (Lake Tropic State Index), DAIpo (Diatom Assemblage Index to Organic Pollution), and AGP (Algal growth potential). In saprobic system, it is used microalgae such as Actinastrum hantzschii var. fluviatile, Asterionella gracillima, Coelastrum microporum, Synedra acus, Dictyosphaerium pulchellum, Micractinium pusillum, Cyclotella meneghiniana, Microcystis aeruginosa, Scenedesmus quadricauda, and Nitzschia palea for assessment water quality. In addition, they have ecologically significant characteristics such as dominant species, cosmopolitan species, redtide causative species etc. Also, microalgae such as Botryococcus braunii, B. sp., Chlorella vulgaris, C. sp., Phormidium sp., Scenedesmus quadricauda, Selenastrum capricornutum, Spirulina maxima, and S. platensis have an effect on improvement of water quality.

• 한국환경보건학회지
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• 제8권1호
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• pp.1-11
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• 1982

A study on the water pollution of Gumho river by the relationship between physio-chemical conditions and water quality level by phytoplankton was examined at 7 sampling positions during the period from Aug. 1 to Nov. 30, 1981. Examination of physio-chemicat water analysis such as temperature, pH, DO, BOD, and biological analysis are as follows: 1. pH was in the range of 6.6-7.3. 2. At all positions DO was0.5-11.9 mg/l. But at Shinchun bridge and Gangchang was 0.5-3.9 mg/l. 3. BOD was in the range of 3.4-29.2 mg/l. Banyawol, Dongchon and Gumdan was shown good condition. But at Shinchun bridge was 21.1-29.2 mg/l. 4. The plankton identification in this study period showed, Cyanophyceae is 7 genera 13 species, Bacillariophyceae is 11 genera 32 species, and Chlorophceae is 17 genera 27 species: total 35 genera 72 species. 5. In the point of phytoplankton classification, upper stream of Banyawol, Dongchon and Gumdan which BOD was 3.4-8.7 mg/l, dominant phytoplanktons were Synedra ulna, Ulothrix sp., Oscillatoria sp. and Frusturia rhomboides. At Shinchun bridge which BOD was 21.1-29.2 mg/l, Microcystis aeruginosa, Closterium acerosum and Oscillatoria sp were found a small. At 3rd gongdan which BOD was 9.2-12.5 mg/l, dominant species were Synedra ulna, Hormidium sp and Actinastrum hantzschii. At Paldal which BOD was 7.8-9.2 mg/l, dominant species were Nitzschia palea, Synedra ulna and Scenedesmus bijuga. At Gangchang of down stream which BOD was 6.9-9.2 mg/l, dominant phytoplanktons were Closterium acerosum, Microcystis aeruginosa and Actnastrum hantzschii. 6. The results of biological water analysis by saprobic system were as follows: Banyawol was from oligosaprobic to $\beta$-mesosaprobic, Dongchon and Gumdan was from $\beta$-mesosaprobic to $\beta$-mesosaprobic, Shinchun bridge was polysaprobic, 3rd gongdan was from $\alpha$-mesosaprobic to $\beta$-polysaprobic, Paldal was $\beta$-polysaprobic and Gangchang was $\alpha$-polysaprobic.

• 환경생물
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• 제29권1호
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• pp.46-51
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• 2011

새만금호의 염습지에 위치한 갯벌 5 지점에서 동정된 부착조류는 5강의 44종이었으며 규조류가 33종으로 가장 다양한 조성을 나타냈다. 2007년 이후 연도별 출현종수에서는 전체적으로 큰 차이가 없는 것으로 나타났다. 출현종 수가 가장 크게 변동한 곳은 D1 지점으로 2009년에는 전년에 비해 2배 이상의 종이 출현하였다. 부착조류 개체수는 대부분 규조류에 의한 것이었다. 세포수와 생물량은 2009년에 가장 높았으며, D1과 D2 지점에 서는 큰 증가를 나타냈다. 부착조류의 개체군 밀도와 생물량은 갯벌의 표층에서 가장 높았다. 개체군 밀도는 2월의 만경 1 지점 0~1mm 깊이에서 2,011 cells $cm_2$로 가장 높았다. 생물량은 D2지점의 0~1mm 깊이에서 $1.35{\times}10^3{\mu}m^3\;cm^{-2}$로 가장 높게 나타났다.

• 환경영향평가
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• 제21권2호
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• pp.229-238
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• 2012

This research was to examine the physiochemical factors and the attached diatoms of ecological wetland in Paju from August 2010 to May 2011. As a result of physicohemical water quality assessment, the water temperature did not fluctuate much due to ample riparian vegetation and aquatic plants growing at the site. Due to the effect of Han River Estuary, site 4, 5 and 6 had high electricity conductivity. The BOD concentration was high at site 2, 3, and 4 caused by decrease in water quantity and inflow of polluted water. At all sites, T-N and T-P concentrations ranged from eutrophic to hypertrophic status. At the downstream, the T-N and T-P concentrations decreased by inhabiting aquatic plant. Total of 98 taxa of attached diatoms were found. As for dominant taxa, Achnanthes convergens, A. minutissima, Gomphonema gracile, G. parvulum, Melosira varians, Navicula seminulum, N. minima, N. pseudolanceolata, Nitzschia amphibia, N. palea, Surirella minuta and Synedra ulna var. fragilariodes appeared. The result of biological assessment of water quality rated the sites B(suboptimal)~D(poor) during seasons of low water temperature, Fall and Winter, with DAIpo ranging 24.1~68.2 and TDI of 48.4~85.6. During Spring and Summer, all sites were rated D(poor) with DAIpo lower than or equal to 40, and TDI above or equal to 70. The biological assessment of water quality at the research site showed inferior TDI result compared to that of DAIpo.

• 한국응용곤충학회지
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• 제18권3호
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• pp.119-126
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• 1979

깨씨무늬병에 심하게 이병된 병팔굉 공시종자는 배양 $5\~7$일에 호영, 내외영 및 주병의 $86\~92\%$ 그리고 과피의 $74\~83\%$가 Helminthosporium oryzae에 감염 되어 있음을 보였다. 동균은 종립전면에 분생포자를 형성하였으며 배유의 약10여세포층까지 감염되어 있었으나 배조직에서는 검출되지 않았다. Fusarium moniliforme는 과피, 경유 및 배조직에서 검출되었으며 F. roseum, Trichoconis padwicku, Curvularia spp., Alternaria tenuis, Cladosporium cladosporoides 및 Phoma sp.는$ 3\%$ 이하의 영 및 과피에서 검출되었다. 배양일주일에 $60\~87\%$가 깨씨무늬 병징을 나타냈으며 $13\~40\%$는 외관상 건전하였다. 깨씨무늬병균은 감염된 종자의 제점으로부터 과피를 거쳐 시아및 유근에 전염 발병케 하였다.

• 환경영향평가
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• 제20권3호
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• pp.281-297
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• 2011

The specie composition, stranding crops and the dominant species of phytoplankton were studied in three streams, Namdae-stream, Yeongok-stream and Sacheon-stream from May 2008 to February 2009. The water qualities of the three streams which run into estuary were also examined using phytoplankton indicators. As the result, the phytoplankton appeared 94 taxa in Namdae-stream, 79 taxa in Yeongok-stream and 73 taxa in Sacheon-stream, diatoms appeared the most in phytoplankton. Genus Navicula and Cymbella in diatoms appeared to be over 10 taxa in each stream, N. cryptocephala, N. cryptotenella and N. gregaria, the pollution tolerance taxa, appeared more frequent in the downstream. Due to the separation of each substrate by the rapid water velocity in the upstream, Achnanthes minutissima, a known periphyton, was dominant in upstream site at Namdae and Yeongok-stream. Some construction areas and sites of downstream of Namdae-stream, Yeongok-stream and Sacheon-stream were shown to be polluted because pollution tolerance taxa, such as Cyclotella meneghiniana, Nitzschia palea and Oscillatoria limnetica, were dominant. The total of 20 taxa phytoplankton indicators were found, composed of 16 taxa of Water pollution algae including Oscillatoria limosa, 2 taxa of Clean water algae Meridion circulare and Staurastrum puntulatum, 1 taxa of Toxic algae Microcystis aeruginosa and 1 taxa of Taste and odor algae Fragilaria construens. Water pollution indicators were appeared frequently in polluted sites of biological water quality(DAIpo, TDI) and of sites containing high trophic state index(TSI). Therefore, using the phytoplankton indicators can assess water quality through relation of biological water quality and trophic state index.

• Molecules and Cells
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• 제27권4호
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• pp.449-458
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• 2009

The OsAsr1 cDNA clone was isolated from a cDNA library prepared from developing seed coats of rice (Oryza sativa L.). Low-temperature stress increased mRNA levels of OsAsr1 in both vegetative and reproductive organs. In situ analysis showed that OsAsr1 transcript was preferentially accumulated in the leaf mesophyll tissues and parenchyma cells of the palea and lemma. For transgenic rice plants that over-expressed full-length OsAsr1 cDNA in the sense orientation, the Fv/Fm values for photosynthetic efficiency were about 2-fold higher than those of wild type-segregating plants after a 24-h cold treatment. Seedlings exposed to prolonged low temperatures were more tolerant of cold stress, as demonstrated during wilting and regrowth tests. Interestingly, OsAsr1 was highly expressed in transgenic rice plants expressing the C-repeat/dehyhdration responsive element binding factor 1 (CBF1), suggesting the regulation of OsAsr1 by CBF1. Taken together, we suggest that OsAsr1 gene play an important role during temperature stress, and that this gene can be used for generating plants with enhanced cold tolerance.

• 자원환경지질
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• 제56권2호
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• pp.185-199
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• 2023

This study aimed to predict the effects of water ecology on the supply of hydrothermal energy to model a housing complex in Eco Delta Smart Village in Busan. Based on the results, engineering measures were recommended to minimize problems due to possible temperature variations on the supply of hydrothermal energy from the river. The current distribution of fish, benthic macroinvertebrates, and phytoplankton in the Pyeonggang Stream was monitored to determine their effects on water ecology. In the research area, five species and three families of fish were observed. The dominant species was Lepomis macrochirus, and the subdominant species was Carassius auratus. Twenty-five species and 21 families of benthic macroinvertebrates were found. The distribution of aquatic insects was poor in this area. The dominant species were Chironomidae sp., Lymnaea auricularia, Appasus japonicus, and Caridina denticulata denticulata in February, May, July, and October. Dominant phytoplankton were Aulacoseira ambigua and Nitzschia palea in February and May. Microcystis sp. was dominant in July and October. The health of the ecology the Pyeonggang Stream was assessed as D (bad) according to the benthic macroinvertebrate index (BMI). Shifts in the location of the discharge point 150 m downstream from intake points and discharge through embedded rock layer after adding equal amounts of stream water as was taken at the beginning were suggested to minimize water temperature variations due to the application of hydrothermal energy. When the scenario (i.e., quantity of water intake and dilution water, 1,600 m³/d and water temp. difference ±5 ℃) was realized, variations in water temperature were assessed at -0.19 ℃ and 0.59 ℃ during cooling and heating, respectively, at a point 10 m downstream. Water temperatures recorded at -0.20 ℃ and 0.68 ℃ during cooling and heating, respectively, at a point 10 m upstream. All stream water temperatures after the application of hydrothermal energy recovered within 24 hours. Future work on the long-term monitoring of ecosystems is suggested, particularly to analyze the influence of the water environment on hydrothermal energy supply operations.