• Environmental Engineering Research
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• v.21 no.2
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• pp.140-144
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• 2016

Owing to the kinetic differences in ammonia oxidation among ammonia-oxidizing microorganisms (AOM), there is no standard set of kinetic values that can be used as a representative set for nitrifying wastewater treatment plant (WWTP) design. As a result, this study clarified a link between the half-saturation constants for ammonia oxidation (Ks) and the dominant ammonia-oxidizing bacterial (AOB) groups in sludge from full-scale WWTPs and laboratory-scale nitrifying reactors. Quantitative polymerase chain reaction analyses revealed that AOB affiliated with the Nitrosomonas oligotropha cluster were the dominant AOM groups in the sludge taken from the low-ammonia-level WWTPs, while AOB associate with the Nitrosomonas europaea cluster comprised the majority of AOM groups in the sludge taken from the high-ammonia-level WWTPs and nitrifying reactors. A respirometric assay demonstrated that the ammonia Ks values for the high-ammonia-level WWTPs and nitrifying reactors were higher than those of the low-ammonia-level plants. Using the Ks values of available AOM cultures as a reference, the Ks values of the analyzed sludge were mainly influenced by the dominant AOB species. These findings implied that.different sets of kinetic values may be required for WWTPs with different dominant AOM species for more accurate WWTP design and operations.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.302-313
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• 2014

This study was conducted to compare the characteristics of fish distribution according to sand type stream and cobble type stream the 4 stream selected every season. The collected Korea endemic species during the survey period were 24, including Acheilognathus gracilis. Dominant species of Hongcheon stream and Muju Namdae stream was Zacco koreanus, each accounting for 39.9% and 28.4% in order, and dominant species in Yanghwa stream was Rhodeus notatus, 13.6%, and those in Gap stream was Z. platypus, by 26.0%. As a result of community analysis, dominant index was 0.27~0.63, diversity index was 1.92~2.67, evenness index was 0.6~0.79, richness index was 3.09~3.53, and dominant index was the highest in Hongcheon stream, and the indices of diversity, evenness and richness were the highest in Yanghwa stream. As a result of tolerance guild analysis, Hongcheon stream and Muju Namdae stream with a variety of substrates accounted for relatively higher rate by 50.1% and 46.4% in sensitive species respectively, and Yanghwa stream and Gap stream with greater sand substrates had 0.5% and 5.3% scarce rate of sensitive species. As a result of similarity analysis using the species, population and substrate structures of the fisheries appeared in each stream, cobble type streams such as Hongcheon stream and Muju Namdae stream were the most similar by 50.4% in species and population, 95.2% in bed structure. As a result of IBI analysis, Hongcheon stream and Muju Namdae stream appeared as 'Class A,' Yanhwa stream and Gap stream as 'Class B' and the two groups of cobble type stream and sand type stream were divided as a result of principal components analysis.

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.996-1008
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• 2016

Effects of substrate types (bedrock and boulder habitat) on the community structures of benthic biota (macroalgae, macrobenthos) were monthly examined at Sinheung in Jeju Island, Korea, from Feb. to Nov. 2015. Species diversity of seaweeds and macrobenthos was greater at bedrock sites with 57 and 102 species than at boulder sites having 42 seaweeds and 67 macrobenthos. Average annual biomass of seaweeds was $1,601.13g\;wet\;wt./m^2$ at bedrock site and $448.85g\;wet\;wt./m^2$ at boulder site. Ecklonia cava was the most dominant species, occupying 62.64% ($1,002.93g/m^2$)of total biomass at bedrock. Amphiroa anceps was the most dominant species and subdominant species was Ecklonia cava, Grateloupia angusta, Peyssonnelia capensis and Meristotheca papulosa at boulder site. Density and biomass of macrobenthos were estimated to be $106.9indivi./m^2$ and $871.93g/m^2$, respectively at bedrock site and they were $64.6indivi./m^2$ and $984.28g/m^2$ at boulder site. The dominant macrobenthos species based on biomass were Turbo comutus (36.40%), Astralium haematragum (19.18%) and Anthocidaria crassispina (13.61%) at bedrock site and they were Alveopora japonica (54.13%) and Psammocora profundacella (24.28%) at boulder site.

• 한국해양학회지
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• v.29 no.3
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• pp.304-318
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• 1994

Macrobenthic fauna in three Keum-Mankyung-Dongjin Estuaries and their nieghbouring coastal region in the west coast of Korea were sampled as 39 stations with van Veen grab to describe the distribution patterns of macrobenthos. Total 61 taxa from 10 faunal taxonomic groups and 5,636 individuals were collected. Abundance, species number, and faunal composition varied among three estuaries and coastal region. Dominant species from estuaries were similar to each other, but different from those of coastal region. Dominant species in estuarine regions were Prionospio cirrifera, potamocorbula amurensis. Nephtys californiensis, Glycera chiron and Glycinde sp, those from coastal area were Mactra chinensis. Magelona japonica, Owenia fusiformis. Anaitides Korean and Nephtys polybranchia. Two most dominant species in estuaries, Potamocorbula amanuensis and Prionospio cirrifer were not found elsewhere in Korean waters. The patchy distribution of dominant species and low species richness were reflected in the low species diversity Filter feeders were a major component in estuaries. High proportion of carnivores and low percentage of subsurface deposit feeders seemed to be a typical trophic composition in the study area. the distribution pattern of macrobenthos was related with the salinity and sediment types.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.4
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• pp.261-270
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• 1998

This study was carried out in order to investigate the distribution and species composition of benthic polychaetous community in northern Kyeonggi Bay in September 1995. Mean density of benthic animals was 557 indiv./$m^2$. Benthic polychaetes were the most dominant faunal group, comprising 60 species with a mean density of 488 indiv./$m^2$. Benthic polychaetes were most abundant in Yumha Channel centering on Incheon Harbor, whereas relatively poor in the intertidal zones fringing Yongjong Island and Songdo area, and in the offshore main channel. The most dominant polychaete was Heteromastus filiformis (47.3% of polychaetous community), followed by Nephtys palybranchia, Tharyx sp., Sternaspis scutata and so on. Kyeonggi Bay could be divided into 4 regions from cluster analysis based on the dominant species composition: offsea/channel region, Incheon Harbor, intertidal zone of Yongjong Island, and intertidal zone of Songdo area. Highest species number and diversity index (H') were recorded at offsea/channel region, whereas highest faunal density at Incheon Harbor. Incheon Harbor was characterized by high abundance of H. filiformis. Compared with the previous studies carried out in Kyeonggi Bay, faunal density and species number have little changed for the recent 10 years. Dominant species was different between each study, but has been among opportunistic species of small-sized polychaetes belonging to capitellids, cirratulids or spionids. These results indicate that Kyeonggi Bay has been organically polluted steadily; specifically, this study reveals that Incheon Harbor has been the center of pollution and that the benthic community in the outer sea off Sihwa dike has become unstable.

• Journal of Marine Life Science
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• v.4 no.2
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• pp.70-80
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• 2019

Ichthyofauna and community structure of fish were studied for two fisheries resource reserves, Chuncheon reservoir and Andong reservoir from 2017 to 2018. Fish were sampled 8 times at each reservoir. In Chuncheon reservoir, total number of fish sampled was 1,197 representing 34 species and 13 families. Dominant species and sub-dominant species were Lepomis macrochirus (23.2%) and Zacco platypus (17.4%), respectively. In Andong reservoir, total number of fish sampled was 1,393 representing 24 species and 9 families. Dominant species and sub-dominant species were L. macrochirus (15.7%) and Carassius carassius (15.2%), respectively. The diversity index of two sampling site increased compared to previous investigation. The evenness index was not changed much in Andong reservoir but increased in Chuncheon reservoir. Ichthyofauna and community structure of fish at sampling sites in both reservoirs maintained stable except high proportion of exotics species with needed to be reduced by consistent effort. For better fish population in these communities, however, various efforts such as seed stocking and installment of artificial spawning ground should be provided to these reservoirs.

• 한국해양학회지
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• v.17 no.1
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• pp.1-11
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• 1982

A study on the community and distribution of phytoplankton of the Kum River Estuary has been done in fall, 1980 and spring, 1981. Ond hundred and one taxa representing 22 families, 41 genera, 107 species, 2 varieties, and 2 forms were identified. The community of the study area composed mainly of diatom species icluding the very small fraction of dinoflagellates, blue-greens and greens. The dominant species were Skeletonema costatum, Paralia sulcata, and Asterionella kariana. The total standing crop of phytoplankton of winter samples was 115,000 cells/1 in average and that of spring samples was, 1,320,333 cells/1 in average. Of the representative members, dominant species above appeared moree than 10% of the total standing crop, Skeletonema costatum being maximized up to 46%. In spring Asterionella japonica, Thalassionema nitzschioides, and Chaetoceros curvistetus appeared 3∼8%, and Thalassiosira excentricus 3% in winter. The distribuion of marine forms showed negative correlation with that of fresh water forms, although the brackish-water forms showed no relationship. This change pattern of marine, brackish and fresh-water forms are discussed with the results of time series analysis. A list of phytoplankton species observed in this study is added.

• Journal of Korean Society of Forest Science
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• v.99 no.5
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• pp.736-743
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• 2010

This study examined the ecological attributes of classified forest community by cluster analysis in the mixed forest of Mt. Seokbyung Experimental Forest of Gangwon-Do. The vegetation data were collected in randomly established 51 sample plots (2.04 ha) and analysis adopted the cluster analysis, importance value index, and Shannon's diversity index. Main results were as follows; 1) the study area was classified into 4 clusters (A, B, C and D). 2) The cluster A was dominated by Pinus densiflora with an importance value of 71.6%. The most dominant species in the cluster B and cluster C were Larix leptolepis (57.1%) and Quercus mongolica (40.2%), respectively. Finally, The cluster D was dominated by P. densiflora (30.6%) and Q. mongolica (31.0%) with the mixed forest. 3) In the P. densiflora community (cluster A), distribution of DBH class showed a reverse J-shaped curve. In the L. leptolepis community (cluster B), individuals of dominant species had the bell-shaped distribution. Oak species indicated uniform distribution of DBH class (under 25 cm) in the mixed P. densiflora - Q. mongolica community (cluster D). 4) The species diversity index of the communities in descending order were: Pinus densiflora - Q. mongolica community > Larix leptolepis community > Pinus densiflora community > Quercus mongolica community.

• Journal of Forest and Environmental Science
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• v.36 no.2
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• pp.78-90
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• 2020

We studied forest structure and composition in the vicinity of Srinagar Hydroelectric Power Project in Alaknanda Valley, Garhwal Himalaya, India to provide baseline data for the management of forests. Eight sites were selected in the vicinity of power project based on elevation and species composition. Density varied from 650 to 340 ind ha^-1 for trees and from 4,360 to 6,480 ind ha^-1 for shrubs. TBC ranged from 35.02 to 54.02 ㎡ ha^-1 for trees and from 0.875 to 2.628 ㎡ ha^-1 for shrubs. On the basis of density and IVI, Pinus roxburghii was found dominant tree species in most of the sites, whereas among the shrubs, Carissa opaca was dominant. Dominance of Pinus roxburghii in most of the sites is an indication towards possible threat to associated species in the area. The dominance-diversity curve of trees showed a geometric distribution, whereas the shrubs displayed log-normal curves. The forest has rich and diverse species composition however; habitat degradation caused by the construction of Power Project might lead to reduction of plant species from the area. The information obtained from this study will be helpful in predicting possible changes in the forest ecosystem properties in near future after completion of the power project.

• The Korean Journal of Ecology
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• v.6 no.4
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• pp.237-242
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• 1983

This is an investigation on the secondary vegetation and succession in the mixed forests destroyed by the severe crown fires on April 8, 1982. The results are summarized as follows: The floristic compositions in the investigated area are composed of 63 kinds of kinds of vascular plants. The biological type shows $ H-D_1, 4-R_5-e$, which is supposed to make a progress to the $ H-D_1-R_5-e$ type. Dominant species are Spodiopogon sibiricus (100.00)-Carex humilis var. nana (70.52)-Miscanthus sinensis var. purpurascens (61, 06)-Lespedeza maximowiczii (57.53). Lespedexa maximowiczii is prevailing as the dominant species in this area. The species diversity(H) and eveness index(e) show 3.00 and 0.74 respectively, so that the species are various and shows uniform distribution comparatively in these communities. Degree of succession(DS) is 479 in the investigated area, the value of which is comparatively higher than that of Chungcheongbuk-do area at the second year afer fires. After the crown and trunk of trees were scorched by the crown fires, the pine tree (Pinus densiflora) died and the other species could be survivd after sometimes. It some that Quercus serrata. Q. dentata, Maackia amurensis, Lespedez cyrtobotrya, Platycarya strobilacea and Lindera glauca are the fire-resistant plants.