• Journal of Ecology and Environment
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• v.41 no.8
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• pp.213-222
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• 2017

Background: This study was conducted to assess the physicochemical water quality and the altitudinal distribution of low-temperature and mountain epilithic diatom (LTMD) community in Buk and Hangae streams that are located in Seorak Mountain with the height of 1708 m in Korea. And the community characteristics of LTMD found in the Buk and Hangae streams were compared to that of LTMD from the Han River system. Results: The physicochemical water qualities of Buk and Hangae streams were determined to be very clean. As a result of analyzing the community composition, 135 taxa of epilithic diatoms were determined, and 22 taxa appeared including Hannaea arcus var. subarcus which are known to have low-temperature and mountain ecological characteristics in the literatures. The relative frequencies of LTMD were 37.0~0.9% range from the upper to lower regions. Although Diatoma tenuis, Eunotia minor, and Gomphonema affine are known to be ubiquitous in streams and lakes, in this research, the three taxa were added into low-temperature and mountain epilithic diatom, since D. tenuis and E. minor appeared only in altitudes above 600 m, and G. affine had the highest relative frequency during spring and fall in altitudes above 700 m, when water temperature was around $10^{\circ}C$. Conclusions: Among the 24 taxa of low-temperature and mountain epilithic diatom (LTMD) (including the 3 taxa added in this study), 14 taxa (Diatoma hyemalis, D. mesodon, D. tenuis, Hannaea arcus, H. arcus var. subarcus, Ulnaria inaequalis, Eunotia bilunaris, E. implicata, E. minor, E. muscicola, E. silvahercynia, E. septena, Delicata delicatula, and Gomphonema affine) represented the characteristics of LTMD very well; they grow best in water temperatures below $15^{\circ}C$ in Buk and Hangae streams and Han River system.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.137-143
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• 2008

The abundance and community structure of epilithic diatoms grown on different substrata were investigated in two first-order streams located in a limestone and granite area, north of the Suzuka Mountains in Central Japan. Experiments were conducted as follows: limestone and granite without algae were submerged in their own streambed or another stream station and incubated for seven weeks, while limestone and granite with algae were transferred to another stream station and incubated at the same time. The diatom biomass was consistently high in the lime-stone station experiments compared to those at the granite station. In addition, there was more diatom biomass on granite substrata than on the limestone substrata at both stations. The present results suggested that the difference in water chemistry including the major nutrient concentrations was the limiting factor for algal growth in these two streams; however, when the water chemistry was the same in each stream, the difference in substratum characteristics became the important factor affecting the diatom abundance. The diatom community grown on the transferred substrata with and without algae became similar to those grown on the original substrata in each stream during the incubation period. It was suggested that the effect of the substrata characteristics on the diatom community structure was rather small.

• Journal of environmental and Sanitary engineering
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• v.19 no.2
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• pp.45-50
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• 2004

To investigate the epilithic diatom community and water quality of the Osan stream, water samples were collected from the eight stations from April to September 2003. Sampling was two times before and after heavy rain. Total 52 diatom were identified and divided into 12 saproxenosus taxa, 6 saprophilous taxa and 34 indifferent taxa, respectively. The DAIpo values higher after heavy rain than before that. According to tolerance degree to the organic water pollution, all sampling stations ranged from $\alpha$-oligosaprobic to $\alpha$-mesosaprobic. Thus, the result indicates that the water quality of Osan stream is gradually improved by heavy rain.

• Korean Journal of Ecology and Environment
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• v.37 no.4 s.109
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• pp.378-384
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• 2004

We investigated the variations of epilithic diatom community and assessed water quality of the water system of Ulleung Island by DAIpo in April, May, July, August, October, and November of 2003, and January and February of 2004. Samples were collected from four sampling stations. Total 95 taxa were identified from this study and dominant species were Nitzschia inconspicua, Achnanthes minutissima, Gomphonema angustum and Cocconeis placentuja var. lineata. The variation of DAIpo values was ranged from 51.14 to 77.77 and the water quality by DAIpo was estimated between ${\alpha}-oligosaprobic$ and ${\beta}- oligosaprobic$ states.

• ALGAE
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• v.21 no.3
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• pp.295-305
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• 2006

The purpose of the study is to understand the ecological characteristics of the early stage of community formation of epilithic diatoms. The samples were daily collected from a site of the Kumho River during 70 days from October 13 to December 21 in 2002. Total 126 diatom taxa collected in the study were classified into 114 species and 12 varieties belonging to 26 genera. About 80% of the taxa collected from the artificial substrata during the whole studying period were observed until tenth day from the start time of the study. In the study the successional process of the diatom community was divided into the three stages of the early, the middle and the later by cluster analysis based on the similarities in species composition among the communities. Cocconeis placentula Ehrenb. and C. placentula var. lineata (Ehrenb.) V.H., horizontally positioned species, would be divided into the early successional species, and Diatoma vulgre Bory, vertically positioned species, was the later successional species. Cell densities and species composition of the diatoms on the artificial substrata were closely similar to them of natural substrata after 40th day from the start time of the study.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2004.05a
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• pp.49-49
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• 2004

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.470-477
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• 2017

The aims of this study were to analyze the physico-chemical factors and the characteristics of epilithic diatom community from 15 sites of the Naeseongcheon and tributaries located in the upper region of the Nakdong river from May to October 2016. The biological water quality was assessed using DAIpo and TDI. A total of 163 diatom taxa were identified with 2 orders, 3 suborders, 9 families, 35 genera, 145 species, 16 varieties and 2 forms. Cocconeis placentula var. lineata appeared at every examined sites. Achnanthes lanceolata, Nitzschia fonticola, Nitzschia inconspicua and Reimeria sinuata were common taxa of the Naeseongcheon. Nitzschia inconspicua and Achnanthes minutissima were major dominant species. As a result of the CCA, Electrical conductivity and total nitrogen concentration were important factors determining the diatom species composition. In the result of the biological assessment using DAIpo, the Naeseongcheon was rated at class B with an average of 62.38. In the result of assessment using TDI, the Naeseongcheon was rated at class C with an average of 66.12.

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.283-291
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• 2014

To study the distribution characteristics of diatom communities in relation to the gradient of water quality and land-use, water samples and epilithic diatoms were collected from 90 sites including mainstream and tributaries, in the Geum River System (GRS) during no rainfall, May 2011. Of 239 taxa identified, Achnanthes convergens and Cymbella minuta were dominated over all the sites. Cluster analysis on the GRS divided into three groups. Group 1 (G1) is the mountainous upstream, a relatively good water quality, and mainly consisted of saproxenous species. Group 2 (G2) is the urban sites, polluted (high in electric conductivity, total phosphate and soluble reactive phosphorus), and saproxenous and common species. Group 3 (G3) is the agriculture sites, and polluted (turbidity, total nitrogen, nitrate), and saprophilous species. There were some discrepancies between abiotic and biotic variables in GRS; biologically similar between G1 and G2, but abiotically similar between G2 and G3. These differences may attribute to not only physiological characteristics of diatom cells, but complicate relationships between microhabitat and water quality. Thus, an urgent development of generalized or standardized methods to diminish the differences between epilithic diatom community and environments is advent.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.70-77
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• 2004

In order to the epilithic diatom community and an assessment of water quality with diatom assemblage index of organic water pollution (DAlpo) in the middle reaches of the Nakdong River, the samples were collected from nine sampling stations on May, July, September, November, 2002 and on January 2003. A total 162 taxa was identified from this study, which were classified into 139 species and 23 varieties belonging to 33 genera. Achnanthes minutissima, Navicula subminuscula, Navicula viridula var. rostellata, Nitzschia inconspicua and Nitzschia palea indentified in every stations and examination for the whole periods. A total of 12 taxa was dominant species at any station at least one more times. In this study, average DAlpo was 30.90 ${\sim}$ 44.61 and the saprobic level was estimated ${\beta}$-mesosaprobic in the middle reaches of the Nakdong River.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.531-537
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• 2012

The information about the physicochemical environments, the species distribution and community of the epilithic diatom cells in Pyengchang river and inflow streams of Gangwon-do were studied for assessment of biological water quality from June 2008 to October 2010. Total 112 diatom taxa were identified with 2 orders, 9 families, 26 genera, 95 species and 17 varieties. Among the total taxa identified, 13 taxa, 52 taxa and 15 taxa represented the family Achnanthaceae, Naviculaceae and Bacillariaceae, respectively. The pH values of the water was found to be neutral to alkaline due to the limestone grounds of Pyengchang river and inflow streams. The 13 taxa including Epithemia adnata, belonged to alkaline-water diatoms, and three species - Cymbella japonica, Eunotia major and Fragilaria capitellata - are known to be acidic-water species. The species, Hannaea arcus, known as a cryophilic and mountain periphyton was identified at IF2, IF3 and IF4 in low water temperature environments at high altitudes, being a dominating species in P1 and IF1. Four saproxenous species - Achnanthes convergens, Cocconeis placentula var. lineata, Cymbella turgidula and Hannaea arcus - were dominant at some sampling sites. For biological water quality assessment, IF2, IF3 and P3 showed low water quality class. The values of DAIpo and TDI were 10.6 ~ 98.0 and 13.8 ~ 94.2, respectively. Therefore, biological water quality in Pyengchang river and inflow streams was relatively desirable.