• ALGAE
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• 제19권3호
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• pp.227-234
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• 2004

A study on the dynamics of phytoplankton community and the physico-chemical environmental factors was performed biweekly from April 1998 to March 1999 in Youngchun Dam. A total 72 phytoplankton taxa was identified and dominant taxa were blue-green algae and diatoms. The highest value of phytoplankton standing crop (24,826cells·ml$^{-1}$) was observed in September 7, 1998, the blooming period of blue-green algae Phormidium sp., while the lowest (318cells·ml$^{-1}$) was measured in June 18, 1999. The phytoplankton communities were dominated by blue-green algae of Anabaena planktonica, Microcystis aeruginosa and Phormidium sp. during the summer and autumn periods and were dominated by diatoms of Synedra acus and Aulacoseira spp. during the spring and winter periods. Secchi disc transparency, chlorophyll-a, total nitrogen, total phosphorus and silicate concentration were varied in the ranges of 0.4-2.5 m, 2.4-32.2mg·m$^{-1}$, 0.845-2.352mg·l$^{-1}$, 0.005-0.093mg·l$^{-1}$, 0.2-15.7mg·l$^{-1}$, respectively. The trophic status of Youngchun Dam were estimated eutrophic according to Lake Trophic States Index (LTSI).

• 한국해양학회지
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• 제14권1호
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• pp.6-14
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• 1979

해양 식물플랑크톤은 해양생태계에서 가장 중요한 생산자로서 해양생물 및 해양환경에 지극히 큰 영향을 미친다. 따라서 식물 플랑크톤은 해양의 생태를 연구함에 있어 중요하고도 우선되는 연구 대상이다. 한국에서는 Skvortzow(1931) 및 산전(1933)가 처음으로 해양 식물플랑크톤을 연구한 이래, 상천(1934), 소구보(1938), 창무(1943, 1944), 박(1956a,b), 최(1966, 1967, 1969, 1972), 엄 유(1967), 이 심 김 (1967), 박 김(1967), 방(1967), 최(1969, 1970), 정 심 이(1970, 1971), 정(1969), 유외(1975), 유 이(1976), 유(1977), 정 이(1977) 등으로 연구가 계속되어 오고 있다.

• Ocean and Polar Research
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• 제42권1호
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• pp.1-13
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• 2020

We analyzed the characteristics of meiofaunal communities in the northern part of Jeju Island and the environmental factors affecting the meiofaunal communities. For the analysis of the communities, subtidal sediments containing meiofauna were collected from 6 sites (3 shallow sites and 3 deeper sites) on the northern coast of Jeju Island in April, June, August, and October 2017. The sediment samples were collected by SCUBA using a syringe. After isolating and counting meiofauna from the sediment using a series of sieves and centrifugation, the density of the meiofauna was expressed as individuals/10 ㎠. Density of meiofauna was lower in August compared to April and June, and the density determined in October was higher than August. During April and June, the meiofaunal communities at the shallow sites (i.e., ST 1, 2, and 3) were significantly different from the meiofaunal communities at deeper sites (ST 4, 5, and 6, p < 0.01). However, such spatial variation in the meiofaunal communities was not obvious in August and October. The most dominant meiofaunal taxa were harpacticoids, followed by nematodes and nauplius larvae. These three taxa accounted for 90% of the total meiofauna density. Abundance of harpacticoids and nematodes showed a significantly negative correlation with the water depth. BIO-ENV analysis indicated that the total organic nitrogen (TON) and the water temperature exerted a significant influence over the meiofaunal communities at the sampling sites.

• The Korean Journal of Ecology
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• 제12권4호
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• pp.257-284
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• 1989

This study was carried out to characterize pinus densiflora forests in middle province (Mt. Seolag, Mt. Taebaik) south province (Mt. Sokli, Mt. Jiri) and south-coast province (Mt. Daedun) of Korea. The appearance species in the P. densiflora alliance included 325 taxa and varied according to the direction of slopes. The steeper the slope was, the fewer number of taxa were observed. The floristic composition of south-coast province was gradually changing to the south hemispheric factors. Dominant species groups of P. densiflora alliance were classified into P. densiflora, Quercus serrata ( layer), Rhus trichocarpa ( layer), Lespedeza maximowiczii var. tomentella (S layer), Artemisia keiskeana, Carex humilis var. nana, Spodiopogon sibiricus (K layer). Quercus variabilis, Fraxinus sieboldiana and Styrax japonica association were formed under the P. densiflora alliance. Quercus, Rhus, Lespedeza and Rhododendron groups maintained high ecological relationships one another. The soil factors (pH, organic matters, and water field capacity)and relative light intensity tended to show negative correlation, which were significantly different among provinces. The P. densiflora forests of Korea were classified into one alliance and four associations, that is, pinion densiflorae Suz.-Tok. 1966, Quercetum variabilae ass. nov., Quercetum mongolicae ass. nov. Fraxinetum sieboldianae ass. nov. and Styraxetum japonicae ass. nov.

• The Korean Journal of Ecology
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• 제11권1호
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• pp.1-15
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• 1988

Studies on species compostion, promary production of benthic algal assemblage were carried out along a channel of the salt marsh near Inch'on, Kyonggi Bay, Korea. Possible biological, physical and KDICical factors controlling the aglal assemblage were also examined. The oveall diatoms were encountered one hundred and thirty-seven taxa, of which the dominant species were Paralia sulcata and Cymatosira belgica. These two species accounted for 32.6% relative abundance throughout the study period. Diatom taxa had no clear seasonal pattern in abundance analysis. But at the algal blooming period in spring, euglenoids occurred with a high abundance. The chlorophyll a content of benthic algae showed definite seasonal pattern. The algal biomass of the appeared to influence the spatial fluctuation in the algal biomass of the channel was regulated primarily by water content of sediment. Grazing by zoobenthos apperaed to influence the spatial fluctuation in the algal biomass of the sediment surface. The algal photosynthesis was measured in the laboratory with oxygen method. Photo-synthetic rate was independent of the temperature under the lower irradiance. The gross production from March to November was estimated to be 190g C/m2 at the channel slope. Photosynthetic efficiency was 0.37% on the basis of the photosyntherically active radiation for the study period.

• Fisheries and Aquatic Sciences
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• 제27권1호
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• pp.23-34
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• 2024

While scientific information on the spatial variation of soda lake Microalgae is important to limnological studies, little information was reported from the Ethiopian Rift Valley Lake, Lake Chitu. This study aimed to understand the spatial distribution of the dominant Microalgae taxa in Lake Chitu, Ethiopia. The collection of samples and in situ measurements of some physico-chemical parameters were recorded at three sites for one cycle in November 2021. Fourteen species or genera of Microalgae were identified. Among those, Bacillariophyta were the most important with regard to species abundance and the rarest in species richness. Cyanophyta were the second-most important group in terms of species richness and rarity. Comparatively, all microalgae taxa were rare at both the anthropogenic areas (AA) and the flooding area (FA), which could be mainly due to intensive human and animal intervention and associated with extreme turbidity. Among Cyanophyta, Chroococcus minutus, Microcystis aeruginosa, and Spirulina platensis/fusiformis were predominant at both AA and FA, revealing their adaptation to less clear water and pollution. But S. platensis/fusiformis attained the highest abundance at the FA, indicating their preference for water in a highly nutrient-enriched area. We concluded that the spatial variation of microalgae diversity in relation to water quality parameters has implications for the importance of microalgae as a baseline indicator of water quality assessment tools in lakes.

• 한국어류학회지
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• 제27권2호
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• pp.104-115
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• 2015

2010년 9월부터 2011년 8월까지 매월 소조기에 낙동강 하구역의 안쪽과 바깥쪽 두 개 정점에서 자치어를 채집하여 종조성의 시공간 분포를 밝혔다. 연구기간 동안 출현한 자치어는 총 7목 26과에 속하는 43개 분류군이 출현하였으며, 망둑어과 자치어가 전체 개체수의 63.1%를 차지하여 가장 우점하였다. 그중 하계 출현 망둑어과 자치어가 개체수비 55.5%로 가장 많이 채집되었다. 그 다음으로 청어 (13.2%), 멸치 (13.0%), 그리고 춘계 출현 망둑어과 자치어 (4.6%), 전어 (3.8%), 동계 출현 망둑어과 자치어 (3.1%), 정어리 (1.2%), 웅어 (0.7%) 순으로 채집되었고, 이들 8개 분류군이 전체 자치어 출현량의 95.0%를 차지하였다. 본 연구에서 출현한 자치어 군집은 총 5개의 그룹으로 구분되었으며, 시기적으로 봄, 여름 및 가을, 그리고 겨울 그룹으로 분리되었다. 특히 여름 및 가을에 자치어 군집의 공간적 분리가 나타났다. 하구역의 안쪽 정점에서는 하계 출현 망둑어과 자치어가 우점하였으며, 바깥 정점에서는 망둑어류 외에 멸치가 우점하였고, 기타 다양한 해수어종의 자치어가 출현하였다.

• ALGAE
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• 제31권1호
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• pp.33-39
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• 2016

Blooms of macroalgae have grown over the planet in recent decades as a possible result of eutrophication of coastal waters. Visually, a bloom forming can be identified by dominant presence of an organism at the expense of others. In mid-January 2014, a forming bloom of red algae was detected on the beach of Garopaba, Santa Catarina State, Brazil. This aroused the interest of tourists and locals as well as the scientific community. Thus, the objective of this study was to characterize and quantify the photosynthetic floating organisms contributing to this phenomenon. In addition, we qualitatively compared algal composition of the bloom to those deposited in the post-beach area and the adjacent rocky shore community. Five sampling points in random patches of floating material were defined. At each point, five replicates were taken with a cube of 32,768 cm³, resulting in a total of 25 samples. Samples were collected in the inner area enclosed by a PVC quadrate of about 900 cm² from the shore and the specimens found in post-beach zone (wrack). Twenty-four taxa of macroalgae were found in the bloom, with Aglaothamnion uruguayense as the dominance one. Ten taxa were found on shore. Only four taxa were found in the post-beach area. The biomass estimated for A. uruguayense in the floating material was 8.35 tons with an estimated area of 52,770 m² . It is possible that this huge biomass value of the bloom is related to the local nutrient intake, and our results reinforce the necessity of coastal integrative management initiatives.

• Ocean and Polar Research
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• 제34권1호
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• pp.1-18
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• 2012

We investigated seasonal changes in the mesozooplankton community structure in November 2006 and February, May, and August 2007 at 12 stations in the semi-enclosed Muan Bay, Korea. Forty taxa were sampled, with an average abundance ranging from 1,459 to 20,078 indiv. $m^{-3}$; the highest abundance was detected in August 2007, and the lowest in February 2007. Acartia omorii, A. hudsonica, A. ohtsukai, Bestiolina coreana, Calanopia sp., Paracalanus parvus s. l., Cirripedia larvae, Decapoda larvae, and Gastropoda larvae were the most abundant taxa detected. The species diversity of the mesozooplankton was high around the inner regions in August 2007 but it was relatively low in November 2006. Non-metric multidimensional scaling (nMDS) revealed significant differences in the structure of mesozooplankton community among the seasons. Canonical correspondence analysis (CCA), performed to examine the relationships among dominant taxa, stations, and environmental variables, showed that most species of copepods were positively correlated with temperature, salinity, chlorophyll a, and COD concentration. Our results suggested that the mesozooplankton community structure observed in this study might be affected partly by the seasonal changes in environmental variables, such as the status of the sluice gates (i.e., open or closed) and the in situ production of resting eggs by major copepods.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.90-90
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• 2019

This study was carried out to investigate the vegetation and vegetation structure of Mt. Man in Hwacheon Gun from April to October 2018. The survey site is located in the northern part of South Korea where the climate is similar to that of North Korea. The purpose of this study is to provide basic information for efficient ecological forest management after unification. A total of 341 vascular plant taxa are recorded, representing 221 genera, 4 subspecies, 42 varieties and 6 forms in 84 families. Rare species, including Crataegus komarovii and Amitostigma gracile are found across 10 taxa; 8 families, 10 genera, 9 species, 1 variety. Naturalized Plants, including Ambrosia artemisiifolia and Erigeron annuus found across 11 taxa; 6 families, 10 genera, 11 species. Dominant tree species of the tree layer based on the highest importance values were: Quercus mongolica (23.47%), Larix kaempferi (11.43%), Fraxinus rhynchophylla (8.30%), in the subtree layer were: Lindera obtusiloba (11.38%), Acer pictum subsp. mono (11.33%), Fraxinus rhynchophylla (9.80%) and in the shrub layer were: Lindera obtusiloba (10.22%), Fraxinus rhynchophylla (8.43%), Rubus crataegifolius (8.00%), in the herb layer Pteridium aquilinum var. latiusculum (5.67%), Oplismenus undulatifolius (5.00%), Lysimachia clethroides (3.49%) respectively. The species diversity of Mt. Man was 1.1764 in the tree layer, 1.2403 in the subtree layer, 1.4135 in the shrub layer, and 1.7416 in the herb layer. In conclusion, if we utilize the flora and vegetation structure surveyed in Mt. Man, we can effectively manage the degraded forests with similar altitudes and climate zones in North Korea.