• Journal of Wetlands Research
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• v.13 no.3
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• pp.643-655
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• 2011

This study addresses the periphytons along the Bukhan river stream and examines the biological indices that represents the river and estimate water quality assessment. Bukhan river in 4 major watershed streams (Bukchon-Hangeychon, Narinchon, Inbukchon, and Soyang river) was selected in 9 points. Land use pattern along the streams showed marked differenced in agriculture areas and forest areas. Lower Soyang streams showed blue-green algae and green algae also appeared in evenly pattern. Thus, the pollution source, biomass and distribution are somewhat correlated, and BOD, SS, biodiversity, and evenness showed a similar pattern. This situation can lead to conclusion of oligotrophic lake with good condition. Therefore, current biological index and is not so desirable for stream degree standard water quality and nutrient level.

• Journal of Korea Water Resources Association
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• v.42 no.6
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• pp.481-491
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• 2009

In this study, a comprehensive field monitoring was conducted to understand habitat conditions of fish species in the upper Geum river. Based on the monitoring data, riverine health conditions such as composition ratio of fish species, richness and dominance indexes, bio-diversity (dominance index, diversity, evenness and richness), and index of biological integrity were assessed, and optimal ecological flowrates were estimated using the habitat suitability indexes established for three fish species Coreoleuciscus splendidus, Zacco platypus and Pseudopungtungia nigra selected as icon species using the physical habitat simulation system (PHABSIM). The total number of species sampled was 20 species, and two sensitive species of C. splendidus (22.4%) and Z. platypus (22.0%) dominated the fish community. The estimated IBI values ranged from 34 to 42 with average being 38 out of 50, rendering the site ecologically fair to good health conditions. An optimal ecological flowrate of 9.0 cms was recommended for the representative fish species at the site.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.1
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• pp.69-77
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• 2010

We examined shrimp and bycatch species composition in the shrimp beam trawl fishery off Wan-do, Korea(in the major or fishing ground)from December 2004 to November 2005. We observed a total of 103, 072 individuals in 96 taxa. By densities of individuals, 96.97% were shrimps, 1.20% decapods, 1.10% fish, 0.30% cephalopods and 0.43% other species. By catch weight, 57.29% were shrimps, 26.33% fish, 6.82% decapods, 4.64% cephalopods and 4.92% other species. In spring, the dominant bycatch species by biomass were Okamejei kenojei, Lophiomus setigerus, and Charybdis bimaculata. In summer, the dominant species were Charybdis bimaculata, Muraenesox cinereus, and Paralichlhys olivaceus. In autumn, dominants were Okamejei kenojei, Conger myriasler, and Sefipinna tenuifilis, and in winter they were Okamjei kenojei, Chaeturichthys stigmatias, and Sillago japonica. Bycatch species composition and individual species abundances differed significantly among seasons, probably indicating that variations were related to the life history characteristics of bycatch species. The diversity index was highest in October (2.797) and lowest in July (1.012). The July dominance index (0.569) was much higher than in other months; evenness was highest in September (0.856) and lowest in July (0.374). During the study period, the bycatch-to-shrimp ratio of this fishery varied from 0.063 in February 2005 to 11.031 in May 2005, with a mean of 3.363 These temporal variations may be linked 10 variations in reproductive behaviors and migration patterns of the marine animals sampled.

• Journal of the Economic Geographical Society of Korea
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• v.18 no.1
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• pp.1-16
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• 2015

It is widely believed that increasing socio-economic polarization inspired by globalization and economic restructuring worsens residential segregation by class in Korean cities. However, the existing literature falls short in showing the recent changes of the residential segregation, particularly after the 1997 financial crisis, with reliable and systematic segregation measures. Noting that there are the two major dimension in residential segregation - evenness-concentration and exposure-clustering - this study introduced not only global measure (dissimilarity index and isolation/interaction index) but also local measures (location quotient and Local Moran's I) for each dimension. These measures are applied to the case study of Seoul in the 2000s. The class is defined by education attainment and the data is obtain through the MicroData System Service System(MDSS). The result shows that the residential segregation by education attainment persists through 2000s and even get worse in some dimension. More significantly, it turns out that high-class and low-class residence are nearly mirror-images of each other, indicating high segregation.

• Journal of Ecology and Environment
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• v.31 no.4
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• pp.309-316
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• 2008

To develop a monitoring method for soil microbial communities in rice paddy fields, we used terminal restriction fragment length polymorphism (T-RFLP) to compare soil bacterial community structure in rice paddy fields experiencing different management practices: organic practices, conventional practices without a winter barley rotation, and conventional practices with a winter barley rotation. Restriction fragment length profiles from soils farmed using organic practices showed very different patterns from those from conventional practices with and without barley rotation. In principal component analyses, restriction fragment profiles in organic practice samples were clearly separated from those in conventional practice samples, while principal component analysis did not show a clear separation for soils farmed using conventional practices with and without barley rotation. The cluster analysis showed that the bacterial species compositions of soils under organic practices were significantly different from those under conventional practices at the 95% level, but soils under conventional practice with and without barley rotation did not significantly differ. Although the loadings from principal component analyses and the Ribosomal DNA Project II databases suggested candidate species important for soils under organic farming practices, it was very difficult to get detailed bacterial species information from terminal restriction fragment length polymorphism. Rank-abundance diagrams and diversity indices showed that restriction fragment peaks under organic farming showed high Pielou's Evenness Index and the reciprocal of Simpson Index suggesting high bacterial diversity in organically farmed soils.

• ALGAE
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• v.30 no.2
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• pp.139-146
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• 2015

Urchin barrens have been a major issue of rocky coastal ecosystems in temperate regions. In South Korea, the east coast and Jeju Island have especially been a focus because the area of barren ground increases in spite of continual efforts to install artificial reefs. This study approached the urchin barrens issue in South Korea, by focusing on a correlational analysis of urchin and macroalgal abundance. Urchin density and algal species coverage were obtained using a quadrat image analysis. Subtidal sites were then classified into three groups according to the average densities of urchins to evaluate the characterization of the macroalgal community: no urchin (NU) zone; transition (TR) zone, $4inds.\;m^{-2};$ and urchin (UR) zone, ${\geq}8inds.\;m^{-2}$. The average urchin density in the study site was $4.7inds.\;m^{-2}$ and 57 macroalgal species were found in the study site. From the NU zone to UR zone, total species number, species diversity index and evenness gradually decreased, whereas the dominance index increased. The algae species with negative correlations were Grateloupia divaricata, Polysiphonia morrowii, Chondracanthus intermedius, Delesseria violacea, Desmarestia viridis; and those with positive correlations were the crustose corallines, Sargassum horneri. Other species were not significantly correlated with urchin density. The significant correlations indicate that the abundance of some macroalgal species is proportionally regulated by sea urchin density. This study also shows how macroalgal vegetation changes in response to an urchin's density gradient in a natural condition; and there is a TR zone that existed with respect to an intermediate level of algal abundance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.1
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• pp.53-60
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• 2016

Seasonal variations in seaweed communities were examined at Gwanmaedo and Yeongsando, Korea, from May 2014 to February 2015. Eighty-nine species were identified, including 11 green, 20 brown and 58 red algae. Seventy-three and 74 species were identified at Gwanmaedo and at Yeongsando, respectively. Sargassum thunbergii and Myelophycus simplex were the dominant species, comprising 60.89 and 39.50% of total biomass, respectively, and S. fusiforme was subdominant at the two sites. Of six functional seaweed forms, the coarsely-branched form was the most dominant, forming about 43% of the species number at Gwanmaedo and Yeongsando. Seasonal seaweed biomasses ranged between 53.10 and 172.85 g/m² (average 93.57 g dry wt./m²) and between 83.11 and 176.20 g (138.21 g/m²) at Gwanmaedo and Yeongsando, respectively. The vertical distribution from the high to low intertidal zone was S. thunbergii and Gloiopeltis furcata; M. simplex and S. thunbergii; and S. fusiforme at Gwanmaedo. Seaweed zonation was distinct at Yeongsando, with S. thunbergii and Gelidiophycus freshwateri; M. simplex and S. thunbergii; and S. thunbergii and S. fusiforme. Seaweed biomass, evenness index (J'), and diversity index (H') values were greater at Yeongsando (138.21 g/m², 0.51, 2.18 respectively) than at Gwanmaedo (93.57 g/m², 0.48, 2.04), indicating that the seaweed community at Yeongsando is more stable than that at Gwanmaedo.

• Ocean and Polar Research
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• v.37 no.4
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• pp.317-325
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• 2015

To evaluate the relative ecological quality of Taean coastal areas in terms of various seaweed community indices, seasonal samplings were taken at the Hakampo, Padori, Chaeseokpo, Mongsanpo and Bangpo shores from March 2006 to January 2007. A total of 105 species were identified; species richness ranged from 37~72 species spatially and from 65~75 species seasonally over the study period. Coarsely-branched seaweeds were dominant in functional group and ESG I (ecological state group I) made up 61 species (58.10%) of the identified macroalgae. The average seaweed biomass at the five study sites was $56.63g\;dry\;wt./m^2$ (range, 36.66 at Hakampo $-73.89g/m^2$ at Mongsanpo). Seaweeds were generally abundant in mid and low intertidal zone. Corallina pilulifera, Ulva australis, Sargassum thunbergii, Neorhodomela aculeata, and Symphyocladia latiuscula were the dominant species across all five study sites. Species diversity was between 1.24~2.30, while species evenness was between 0.40 and 0.61. The dominance index ranged from 0.43 at Padori to 0.64 at Mongsanpo. Given the community indices and shore descriptions, the five study sites were divided into two groups based on ecological quality: moderate (Chaeseokpo and Mongsanpo) and good (Hakampo, Padori and Bangpo).

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.3
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• pp.196-203
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• 2004

The study of site characteristics and vegetation structure was carried out to provide basic data for conservation and reasonable management of Korean endemic Corylopsis coreana communities in Jukgok and Ogok-myeon in Gokseong, Jeonnam Province. In C. coreana communities, average soil pH was 5.05, and the content of organic matter, total N and available P was 5.22%, 0.24% and 3.25ppm, respectively. According to the importance value of each layer, Pinus densiflora, uercus variabilis of Jukgok and uercus mongolica, serrata, and Pinus densiflora of Ogok area in the tree layer were high. In the subtree and shrub layer at two study sites, C. coreana has the highest importance value. In subtree layer at the two study sites, species diversity, evenness and dominance ranged from 0.567 to 0.779, 0.401 to 0.509 and 0.491 to 0.509, respectively. The distribution patterns by Morisita's index showed that C. coreana in two study sites was randomly distributed in the subtree and shrub layers.

• The Korean Journal of Ecology
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• v.24 no.4
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• pp.233-237
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• 2001

Changes of the oribatid mite species composition during the litter decomposition was investigated in the north-facing and south-facing slopes with different lower vegetation (annual herbaceous plants in north and perennial Sasa in south) in the altitude 1,000 m of Mt. Jumbong, a nature reserve area in Korea, from August 1994 to September 1995. Total 58 species of oribatid mites were collected. The values of O1son's negative exponential index (k) were -0.56 in the south-facing slope and -0.49 in the north-facing slope, but there was no significant difference between them. The decomposition rate of litter increased rapidly until Oct. 1994, and decreased thereafter. Intensive settlement of the forest litter by oribatid mites was recorded in the autumn periods and it decreased in the next spring and summer. Species diversity index (H'), and species evenness (J') ranged from 1.74 to 2.69, and from 0.57 to 0.93, respectively, and the values were lowest in spring. In the successive periods of growing season, there followed great changes in the structure of species dominance. Heminothrus minor was one of the most dominant species in autumn in the first year when litter were placed, but was never recovered next seasons. In contrast, Platynothrus yamasakii was also dominant in the first autumn, then decreased very low in numbers in next spring and summer, but regained its number in autumn. On the other hand, an increase of the number during these periods was observed by Epidamaeus sp.2. Ceratopia bipilis and Epidamaeus sp.1 were abundant both in the north-and south-facing slopes. Trichogalumna nipponica was only found in the south-facing slope, and Nanhermannia elegantula was only found in the north-facing slope.