• Korean Journal of Ecology and Environment
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• v.50 no.3
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• pp.325-336
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• 2017

The ecosystem in the Gwangju Stream has taken a wide range of disturbance such as the discharging water of sewage treatment plant, the lake water and the river water from different water system over the past decade. This study was figured out some significant influence factors by analyzing the relationship between biotic and abiotic factors in the urban stream. Abiotic components included 15 water quality variables which were measured in five sampling sites along the stream from October 2014 to July 2015, whereas the benthic macroinvertebrates found in those sites were used to estimate various biotic indices representing the ecological status of the community. The results of correlation analyses indicated that abiotic factors by human activities affected on the inhabitation of benthic macroinvertebrates more than biotic factors. The results of cluster analyses and ANOVA tests also showed that biotic and abiotic characteristics were clearly different in season. The main influence factors of cluster analysis by sites were $NH_3-N$, EPT(I) and DO. It was considered that more various statistical analyses would be necessary to find some different relationships and influence factors between biotic and abiotic variables in the urban stream.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.165-173
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• 2020

The activity of living microorganism directly or indirectly affects to the biomineralization in sediments and rocks that display the unique biotic structure. Minerals in the biotic structures showed unique properties and bypass the thermodynamic and kinetic barriers. Therefore, investigations on the biotically induced microstructure is essential to identify the new mineral formation mechanism by analyzing crystal structures and morphology at a nano-scale. The significant implication as well as advantages of using scanning electron microscopy to characterize the biotic structures were discussed in this paper for the examples of hydrothermal vent area microbial mat and deep-sea ferromanganese crust sample.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.908-926
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• 2014

This study investigated the community structure and health assessment of macrobenthic assemblages in Wonmun Bay, in the southern coast of Korea. The total number of species and mean density were 170 species and $1,269\;indivuduals/m^2$, respectively. The major dominant species were the bivalve Theora fragilis ($230{\pm}446\;indivuduals/m^2$) and the polychaetes Lumbrineris longifolia ($180{\pm}339\;indivuduals/m^2$), Sigambra tentaculata ($124{\pm}153\;indivuduals/m^2$), Paraprionospio patiens ($104{\pm}293\;indivuduals/m^2$) and Capitella capitata ($82{\pm}223\;indivuduals/m^2$). Community statistics [cluster analysis and nonmetric multidimentional scaling (NMDS) ordination] revealed that the macrobenthic community structure in the study area was classified into three station groups for both seasons. Several biotic indices based on macrobenthic communities have been developed to assess the ecological quality of coastal ecosystems. In this study, the ecological status was assessed by four biotic indices Shannon's H', the AZTI Marine Biotic Index (AMBI), multivariate-AMBI (M-AMBI) and the Ecological Conservation Index (ECI). The ecological statuses of the macrobenthic communities in Wonmun Bay were poorer in the summer than in the spring. The results of the present study indicate that three biotic indices ( i.e.; Shannon's H', M-AMBI and ECI ) were better correlated with bottom dissolved oxygen than the AMBI in Wonmun Bay.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.107-113
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• 2012

Trichomes are specialized epidermal structure having the functions of physical and chemical block against biotic and abiotic stresses. Several studies on $Capsicum$ species revealed that virus and herbivore resistance is associated with trichome-formation. However, there is no research on the structural characterization of trichomes developed on the epidermis of $Capsicum$ spp. Thus, this study attempts to charaterize the trichome morphologies in 5 species of $Capsicum$ using a Field Emission Scanning Electron Microscopy (FESEM). Six main trichome types were identified by their morphology under FESEM. Both glandular and non-glandular types of trichomes were developed on the epidermal tissues of $Capsicum$ spp. The glandular trichome were further classified into type I, IV and VII according to their base, stalk length, and stalk. Non-glandular trichomes were also classified into type II, III, and V based on stalk cell number and norphology. Almost all the species in $C.$ $chinense$ and $C.$ $pubescens$ had glandular trichomes. To our knowledge, this is the first study on classification of trichomes in the genus $Capsicum$ and, our results could provide basic informations for understanding the structure and function of trichomes on the epidermal differentiation and association with biotic stress tolerance.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.198-205
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• 2008

Benthic macroinvertebrates were examined to elucidate community structures of a set of 9 shallow ponds from a total of 6 parks located in Seoul metropolitan area, Korea. The result showed that macroinvertebrates were diverse and abundant, and aquatic macrophyte provide habitat diversities in ponds. The differences among benthic macroinvertebrate community compositions seemed to be attributed to local biotic and abiotic interactions. We surveyed benthic macroinvertebrate, biotic (macrophyte), abiotic (turbidity, nutrient concentrations, conductivity, heavy metal concentration) and morphometric (area, depth) of the lentic systems. Generally, the benthic macroinvertebrates were dominated by Cloeon dipterum or Coenagrion sp.. Distribution of the aquatic macrophyte community was correlated with the species composition of macroinvertebrates. The result demonstrated a significant and positive relationship between habitat quality and macroinvertebrate composition.

• Journal of Forest and Environmental Science
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• v.35 no.3
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• pp.189-196
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• 2019

Plants are consumed by a myriad of organisms that compete for resources. Direct interactions among multiple plant-feeding organisms in a single host can range for each species from positive to negative. Wood-boring beetle faces a number of biotic and abiotic constraints that interfere with the good prospects from the tree. Biotic factors, including arthropod pests and diseases, and abiotic factors, such as drought and water-logging, are the major constraints affecting the species. The present study aimed to provide basic data for analyzing forest health, identify the kinds of wood-boring beetles in the central part of Korea. Our second goal was to analyze the species composition and diversity of regional communities and to examine. A total of 10,461 individual wood-boring beetles belonging to 8 families and 50 species attracted to trap trees in the pine forests were recorded during the study period on study sites. The results of the analysis of collected species showed that the community structure on all study sites was similar. Seasonal occurrences of dominant wood-boring beetles (5 species) from each study site showed the highest number of all species, except for Siphalinus gigas in May, followed by a gradual decline, and the largest number of Siphalinus gigas appeared in June. The similarity index of species composition was relatively high, ranging from 0.75 to 0.90 for each study site.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.1-10
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• 2012

The Jinwi stream, which is located in the Gyeonggi Province, shows a large variation in water quality from the upper stream to downstream. Therefore the Jinwi stream is suitable for assessing changes to the benthic macroinvertebrate community structure according to saprobity. This study was conducted to find out the applicability of biotic indices for water quality pollution through an analysis of the correlation between water quality and benthic macroinvertebrate indices for the Jinwi stream. Along with the pollution of water, the species composition of Ephemeroptera decreased, while that of Annelida increased. The ecological score for the benthic macroinvertebrate community (ESB) showed more significant correlations than any other biotic index (H', DI, R1, J, EPT and KSI) with the water quality items.

• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.374-390
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• 2006

The analysis of correlation between the 9 element (used as the classification standard of stream typology out of the 25 elements pertinent to the survey of hydromorphological structure) and both emerged benthic macroinvertebrate as well as vegetation indicated that the substrate diversity, curvature, and degree of development of the transverse bar had a high correlation with the species composition. Only COD concentration was found to have the statistically significant correlation with the distribution of benthos among the 12 aquatic and chemical elements. Specifically, the analysis of the biotic and abiotic factors in this study indicated that there was a statistically significant correlation between the sand river and cobble river in the positive(+) and negative(-) aspects, suggesting that there is a distinctive difference between the two types of rivers in terms of hydromorphologlcal structure and ecological characteristics. Therefore, the findings of this study imply that the consideration of a biotop is prerequisite for the evaluation of stream status regarding stream restoration or the ecological topology of streams.

• Journal of Korean Society on Water Environment
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• v.29 no.6
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• pp.825-831
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• 2013

The Suwon stream which consists of a mountainous reach, an artificial reservoir and an urban reach provides benthic macroinvertebrates with various habitats. This study was conducted to find out the influence of reservoir sluice control and water quality on benthic macroinvertebrates community in the Suwon stream from June to August, 2011. As a result, substrate composition showed little difference between the upper site (S2) and the lower site of the reservoir (S3). At site S3, water velocity was fastest, and water temperature was lowest due to the intermediate depth discharge of the reservoir. Cheumatopsyche brevilineata which prefer fast water velocity was dominant at site S3. Some biotic indices (H', J, and R) of site S3 decreased significantly whereas Benthic Macroinvertebrate Index (BMI) showed little difference between site S2 and site S3. EPT showed a negative correlation with water temperature. The sluice control of the reservoir leaded variations of water velocity and temperature, and seemed to make the state of aquatic ecosystem worse.

• Ocean and Polar Research
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• v.44 no.2
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• pp.113-126
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• 2022

This study was carried out to investigate the benthic polychaetous community and benthic ecosystem quality status on the adjacent continental shelf of Jeju Island, and field surveys were conducted at 31 stations in July and August, 2020. The surface sediment was generally composed of muddy sand facies and sandy mud facies, and the average particle size was medium silt (6.1±1.6∅). The benthic polychaetous community revealed a total of 73 species with a mean density of 242 ind./m². The major dominant species were Notomastus latericeus, Ampharete arctica and Onuphis shirikishinaiensis. By the cluster analysis and nMDS results based on species composition of the benthic polychaetous community, the study area was divided into three station groups arranged from east to west by the water depth and sedimentary facies. The station group located in the west was subdivided into two station groups from south to north. From results of correlation analysis and PCA, it was found that the benthic polychaetous community in the study area had a strong correlation with the sedimentary environment and water depth. The benthic faunal community (or ecosystem) on the adjacent continental shelf of Jeju Island was assessed to be in a healthy state by biotic indices such as AMBI and BPI.