• The Plant Pathology Journal
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• v.37 no.1
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• pp.1-23
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• 2021

Resistance to diseases caused by turnip mosaic virus (TuMV) in crop species of the family Brassicaceae has been studied extensively, especially in members of the genus Brassica. The variation in response observed on resistant and susceptible plants inoculated with different isolates of TuMV is due to a combination of the variation in the plant resistome and the variation in the virus genome. Here, we review the breadth of this variation, both at the level of variation in TuMV sequences, with one eye towards the phylogeny and evolution of the virus, and another eye towards the nature of the various responses observed in susceptible vs. different types of resistance responses. The analyses of the viral genomes allowed comparisons of pathotyped viruses on particular indicator hosts to produce clusters of host types, while the inclusion of phylogeny data and geographic location allowed the formation of the host/geographic cluster groups, the derivation of both of which are presented here. Various studies on resistance determination in particular brassica crops sometimes led to further genetic studies, in many cases to include the mapping of genes, and in some cases to the actual identification of the genes. In addition to summarizing the results from such studies done in brassica crops, as well as in radish and Arabidopsis (the latter as a potential source of candidate genes for brassica and radish), we also summarize work done using nonconventional approaches to obtaining resistance to TuMV.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.1
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• pp.20-31
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• 2002

This study was carried out to investigate the composition and the distribution of the benthic polychaetous communities in Deugryang Bay, semi-enclosed bays, on the southern coast of Korea and to deduce temporal changes in community with the comparison of the past studies. In Deugryang Bay, benthic polychaetous community structure was investigated on the base of the samples from 98 stations in 1996 and 1997. The main facies of surface sediment was clayey silt. The overall benthic macrofaunal density was 871 ind./m$^{2}$. The density was highest in the middle part of the bay because Musculus senhousia (Bivalvia) and cumaceans (Crustacea) had their highest densities in some stations. Benthic polychaetes were comprised of 100 species with a mean density of 138 ind./m$^{2}$. Their abundances were higher in the inner bay, in the middle bay, and in the mouth of bay, but poor community structures were established in the whole bay. The dominant species over 1.0 percentage were composed of the total 21 species, and they occupied 78.3% of the total abundance of the benthic polychaetes. The most dominant species was Lumbrineris longifolia (9.3%), followed by Eteone longa (7.3%), Heteromastus filifomis (7.1%), Sternaspis scutata (6.1%). From the cluster analysis, the study area could be divided into three station groups. Station group AI was located in the inner bay and in the shallow coastal region, and its most dominant species was Heteromastus filiformis. At the station group AII in the mouth of bay and in some channel region, its most dominant species were Lumbrineris longifolia and Eteone longa. And at the station group B located in middle part of the bay, the most dominant specis was Sternaspis scutata. In comparison with previous studies, the benthic polychaetous community experienced great change in the view of species number, density and dominant species. The dominant species were Sternaspis scutata and Eteone longa, but their densities declined greatly. Instead of these species, Lumbrineris longifolia and Heteromastus filiformis, known as the potential organic enrichment indicator species, appeared to the new dominant species even if their low densities. These facts mean that Deugryang Bay was maintained yet as little organic enriched area compared to other bays on the coast of Korea, but needed some caution of marine environmental management.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.645-653
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• 2019

The purpose of this study was to understand the factors that affected activities and differences in seasonal activities of the invasive red-eared slider turtle (Trachemys scripta elegans) at Ansan reed wetland in Sangnok-gu, Ansan, Gyeonggi Province, the Republic of Korea. We installed nine nets in the study region to capture turtles and checked the nets twice a day for 154 days from April 28 to September 28 2013. In total, 60 individuals, including 12 juveniles, 26 adult males, and 22 adult females, were captured in 96 of 308 net checks. The multiple regression analysis of 12 environmental factors was conducted to analyze activity factors of red-eared slider turtle by assuming the number of turtles captured for a week to be the indicator of the activeness of the turtles. The result showed that the daylength was the only environmental factor that significantly affected the turtles' activity (p<0.001), and none of the other factors showed a significant correlation. The highest activity was recorded at the end of May, which was the beginning of the reproductive period. The daylength during the breeding season was significantly different from that during other seasons (Kruskal-Wallis test, p<0.001). The information about the relationship between environmental factors and species in habitat can be useful for the management of invasive alien species in the future.

• Journal of agriculture & life science
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• v.46 no.4
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• pp.57-68
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• 2012

This study was conducted to provide basic data for the effective conservation and management in the black pine(Pinus thunbergii) stand which is located in the eastern coast of Gyeongsangbuk-do where the fragmentation of vegetation has been caused by the exploitation and the increase of tourists, and installed the seventy study sites($20{\times}20m$) in the dominant black pine stand. The black pine stand was classified into three groups(P. thunbergii - P. densiflora community, P. thunbergii - Robinia pseudoacacia community, P. thunbergii - P. densiflora-Celtis sinensis community) by a cluster analysis. As a result of Multi-Response Permutation Procedures test, there is significance among the communities. Pinus densiflora, Callicarpa japonica, Juniperus rigida, Rhododendron yedoense for. poukhanense etc. nineteen species were significant by indicator species analysis. The population structure of black pine stand showed that the class of diameter 12 to 26 cm was dominance, which had the inverse hump-shape pattern. Species diversity index(H') of investigated ranged from $1.033{\pm}0.234$ to $1.629{\pm}0.226$ in the woody layer group and from $2.448{\pm}0.457$ to $2.545{\pm}0.318$ $2.174{\pm}0.333$ in the herb layer group.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.20-31
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• 2024

This study was conducted to investigate the changes in the structure of benthic communities resulting from aquaculture activities and to assess the benthic health status of surface sediment in Gangjin Bay, a region known for concentrated shellfish aquaculture on the southern coast of Korea. Survey stations were divided into longline culture, bottom culture, and non-cultivation areas. The spatiotemporal distribution of physiochemical factors such as the grain size, water temperature, salinity, and total organic carbon in Gangjin Bay showed no significant differences between sampling stations. However, the species number, density, and diversity were relatively lower at the sampling stations in the bottom culture areas than at the other stations throughout the entire survey period. Cluster analysis and principal coordinates analysis also clearly distinguished the benthic communities in the bottom culture areas from those in the other sampling areas. At the sampling stations in the longline culture and non-cultivation areas, Scolectoma longifolia and Sigambra tentaculata, which are indicator species of organically enriched areas, appeared as dominant species. However, excluding some stations influenced by physical factors such as the water depth and current speed, the occupancy rate was not high. The health assessment results, conducted using the fisheries environment assessment method, revealed good conditions with Grades 1 and 2 across the entire area. However, an examination of the spatiotemporal changes in benthic communities and the benthic health index indicated that the benthic environment in the bottom culture areas was affected by physical disturbances.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.561-569
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• 2012

This study estimates landscape indices of the Gyeongan-stream watershed from 1975 to 2000 by classifying the land cover into impervious cover and pervious cover depending on its state using a landscape analysis program. For the indicator of biodiversity this study uses Total Core Area(TCA) among landscape indices. The estimated TCA is then used along with an Impervious Cover Model(ICM) to compare the number of fish species that appear in the Gyeongan-stream watershed. In the relations between TCA and the impervious cover ratio, it has been found that as the impervious cover ratio increases, TCA decreases accordingly. It shows that as the ratio of impervious cover in the landscape increases due to urbanization and development, the critical area that individual species need for isolation from outside has decreased. Also, the monitoring of the number of fish species that appear in the Gyeongan-stream watershed shows that in the areas with low impervious cover ratio there are more fish species appearing that inhabit in clean, uncontaminated water. It has been identified that the Gyeongan-stream watershed falls into the category of Impacted Stream and that its state is worsening, and since the watershed in this area responds to the impervious cover ratio very sensitively, its fish diversity it is required to improve the state of the basin through its proper and careful management.

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.519-526
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• 2015

This study was investigated to analyze stand structure in Daegu Dodong T.orientalis Forest for conservation Thuja orientalis forest. Results of cluster analysis, it was classified to Quercus variabilis group(A), Quercus variabilis-Quercus mongolica group(B), Pinus densiflora group(C), Thuja orientalis group(D). Charaters of location environments for D group were analyzed that altitude 99.3 m, slope $59^{\circ}$, rock exposure 68.3%, BHA $21.8m^2/ha$ and North West aspects. The MRPP-test, It classified groups, appropriately. Importance value of D group was T. orientalis 85.42, Q. variabilis 1.28, P.densiflora 1.30, Fraxinus rhynchophylla 3.56 etc. DBH classes of D group were expressed inverted-J-shaped curve. H' was resulted in 0.600~0.834, H'max 1.317~1.466, J' 0.456~0.594, D' 0.405~0.544. Indecator species Analysis were conducted that woody plants were 4 taxa, Herbal plants 9 taxa.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.1-16
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• 2024

Most wetlands worldwide have suffered from extensive human exploitation. Unfortunately they have been less explored compared to river and lake ecosystems despite their ecological importance and economic values. This is the same case in Korea. This study was aimed to estimate the assemblage attributes and distribution characteristics of benthic macroinvertebrates for fifty wetlands distributed throughout subtropical Jeju Island in 2021. A total of 133 taxa were identified during survey periods belonging to 53 families, 19 orders, 5 classes and 3 phyla. Taxa richness ranged from 4 to 31 taxa per wetland with an average of 17.5 taxa. Taxa richness and abundance of predatory insect groups such as Odonata, Hemiptera and Coleoptera respectively accounted for 67.7% and 68.2% of the total. Among them Coleoptera were the most diverse and abundant. Taxa richness and abundance did not significantly differ from each wetland type classified in accordance with the National Wetland Classification System. There were three endangered species (Clithon retropictum, Lethocerus deyrolli and Cybister (Cybister) chinensis) and several restrictively distributed species only in Jeju Island. Cluster analysis based on the similarity in the benthic macroinvertebrate composition largely classified 50 wetlands into two major clusters: small wetlands located in lowland areas and medium-sized wetlands in middle mountainous regions. All cluster groups displayed significant differences in wetland area, long axis, percentage of fine particles and macrophyte composition ratio. Indicator Species Analysis selected 19 important indicators with the highest indicator value of Ceriagrion melanurum at 63%, followed by Noterus japonicus (59%) and Polypylis hemisphaerula (58%). Our results are expected to provide fundamental information on the biodiversity and habitat environments for benthic macroinvertebrates in wetland ecosystems, consequently helping to establish conservation and restoration plans for small wetlands relatively vulnerable to human disturbance.

• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.33-41
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• 2015

In this study, an optimal improvement method of stream channel structure is presented for the enhancement of fish habitat suitability by genetic algorithm. The correlation between fish habitat suitability and physical disturbance in stream is analyzed according to the changes of hydraulic characteristics by channel structure rehabilitation. Zacco koreanus which is an indicator fish of the soundness of aquatic ecosystem was selected as a restoration target species by investigating the community characteristics of fish fauna and river environments in Wonju stream. The habitat suitability is investigated by PHABSIM with the habitat suitability index of Zacco koreanus. Hydraulic analysis by HEC-RAS and physical disturbance evaluation in stream are carried out. The optimal channel width modified for the enhancement of fish habitat suitability is provided. The correlation analysis between habitat suitability and physical disturbance with the change of hydraulic characteristics by channel modification showed that the proper channel modification enhanced fish habitat suitability and mitigated physical disturbance in the stream. The improvement of physical disturbance score by the channel structure rehabilitation for the enhancement of fish habitat suitability was confirmed in this study.

• Korean Journal of Environment and Ecology
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• v.11 no.4
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• pp.462-468
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• 1998

Vegetational data from 25 quadrats of Quercus mongolica communities at Hangyeryong and Paekdamsa area in Soraksan National Park were analysed by applying two multivariate methods: two-way indicator species analysis(TWINSPAN) for classification and canonical correspondence analysis(CCA) for ordination. The forest vegetation of Quercus mongolica community was classified into Quercus mongolica-Tilia amurensis, Quercus mongolica-Abies holophylla, Quercus mongolica-Styrax obassis, and Quercus mongolica-Quercus serrata groups according to the TWINSPAN. The relationships between the distribution of dominant groups according ot the TWINSPAN. The relationships between the distribution of dominant groups for forest vegetation and soil condition in Quercus mongolica communities were investigated by analysing elevation and soil nutrition gradients. Quercus mongolica-Tilia amurensis group was distributed in the high elevation and poor nutrition area of total nitrogen and C.E.C., Quercus monholica-Abies holophylla group was distributed in the high elevation and good nutrition area of total nitrogen and C.E.C., Quercus mongolica-Styrax obassia group was distributed in the medium elevation and poor nutrition area of total nitrogen and C.E.C., while Quercus mongolica-Quercus serrata group was distributed in the low elevation and poor nutrition area of total nitrogen and C.E.C.. The dominant factors influencing community distribution were elevation, total nitrogen and C.E.C..