• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.546-552
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• 2007

The objectives of this study were to analyze fish compositions, based on trophic guilds and tolerance guilds and determine community characteristics structure at five sampling sites of Yeongsan Lake during July 2006-May 2007. Total number of species sampled was 30 species and the number was 1350. Cyprinidae (77%) and Centrarchidae (15.7%) dominated the community and then followed by Cobitidae(2.7%), Gobiidae(2.4%), Mugilidae (0.5%), and others (0.1%). The relative abundance of tolerant and omnivore species at all sites was 63% and 77% of the total, respectively, suggesting an ecological degradations in the Lake. Exotics species such as large mouth bass (Micropterus salmoides), which is a top-carnivore in the water distributed at all sampling sites, implying that ecological disturbance was severe based on previous reference of US EPA (1991). Also, we found external anomalies such as external deformities, bleeding and tumors and not found migratory fish. Analysis of fish community structure showed that species diversity index and richness index was the highest in Site 1 and the dominance index was the highest in Site 2. In this study, high proportions of tolerant species and omnivore species, widespread exotic species, and frequent observations of abnormal fish. Such problems may be directly or indirectly associated with high nutrient enrichments and the reduced flow velocity by the dam construction. The ecosystem restoration by dam removal or removal of exotic top-carnivore fish may be one of the best strategies for better lak management.

• Journal of Environmental Science International
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• v.26 no.7
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• pp.837-846
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• 2017

This study aimed to investigate the dilapidated Fine View Square located in the city of Gangneung and analyze problems for building it into a sustainable space under an effective management plan. Further to creating an ecological base for restoring the natural circulation, a restorative method for the damaged area, a spatial assignment by the UNESCO's Man and Biosphere Programme (MAB), and an urban ecological park, we not only wanted to provide an environment that is citizen friendly, but also a practical and realizable project to connect with the various methods and programs mentioned above, while utilizing the Ministry of the Environment 's ecosystem conservation fund. In conclusion, we found that it would be possible to contribute to building an urban ecological park the Ministry of Environment proposed while restoring the lost natural circulation in Gyodong Square in the city of Gangneung and ecological soundness of the city along with the reduced heat island effect and the increased biological diversity and Ecological Soundness.

• ALGAE
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• v.34 no.1
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• pp.57-70
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• 2019

DNA metabarcoding is currently used for large-scale taxonomic identification to understand the community composition in various marine ecosystems. However, before being widely used in this emerging field, this experimental and analytic approach still has several technical challenges to overcome, such as polymerase chain reaction (PCR) bias, and lack of well-established metabarcoding markers, a task which is difficult but not impossible to achieve. In this study, we present an adapted PCR-free small-organelles enriched metagenomics (SoEM) method for marine biodiversity assessment. To avoid PCR bias and random artefacts, we extracted target DNA sequences without PCR amplification from marine environmental samples enriched with small organelles including mitochondria and plastids because their genome sequences provide a valuable source of molecular markers for phylogenetic analysis. To experimentally enrich small organelles, we performed subcellular fractionation using modified differential centrifugation for marine environmental DNA samples. To validate our SoEM method, two marine environmental samples from the coastal waters were tested the taxonomic capturing capacity against that of traditional DNA metabarcoding method. Results showed that, regardless of taxonomic levels, at least 3-fold greater numbers of taxa were identified in our SoEM method, compared to those identified by the conventional multi-locus DNA metabarcoding method. The SoEM method is thus effective and accurate for identifying taxonomic diversity and presents a useful alternative approach for evaluating biodiversity in the marine environment.

• Animal Systematics, Evolution and Diversity
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• v.40 no.1
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• pp.21-34
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• 2024

Two arenicolus halacarid species, Actacarus ornatus n. sp. and A. pacificus Bartsch, 1979, are recorded from sandy intertidal sediment along the coast of South Korea. Actacarus ornatus n. sp. closely resembles A. karoensis Abé, 1990, recorded from Japan, in having chaetotaxy of the idiosoma, legs, palps of gnathosoma, and perigenital setae in both males and females. However, it differs from A. karoensis by a slightly convex tectum, the presence of a row of foveae on the mid-ventral surfaces of the anterior epimeral plate and genitoanal plate, and the absence of areolae on both the anterior and posterior dorsal plates as well as microplatelets on the membranous cuticle alongside the anterior and posterior dorsal plates. Actacarus pacificus Bartsch, 1979, which is widely distributed in the Indo-Pacific region, is characterized by separated plates, a truncated tectum, the anterior epimeral plate with four pairs of setae, the posterior epimeral plate with one dorsal and two ventral setae, and three pairs of subgenital setae in males. A comparative analysis of the morphological characteristics of A. pacificus was conducted within regional populations, including the Korean population. Moreover, a key to Actacarus species from the northwestern Pacific, including a new species, is provided. The genus Actacarus is reported for the first time from Korea.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1615-1624
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• 2023

Microcystis blooms threaten ecosystem function and cause substantial economic losses. Microorganismbased methods, mainly using cyanobactericidal bacteria, are considered one of the most ecologically sound methods to control Microcystis blooms. This study focused on gaining genomic insights into Paucibacter aquatile DH15 that exhibited excellent cyanobactericidal effects against Microcystis. Additionally, a pan-genome analysis of the genus Paucibacter was conducted to enhance our understanding of the ecophysiological significance of this genus. Based on phylogenomic analyses, strain DH15 was classified as a member of the species Paucibacter aquatile. The genome analysis supported that strain DH15 can effectively destroy Microcystis, possibly due to the specific genes involved in the flagellar synthesis, cell wall degradation, and the production of cyanobactericidal compounds. The pan-genome analysis revealed the diversity and adaptability of the genus Paucibacter, highlighting its potential to absorb external genetic elements. Paucibacter species were anticipated to play a vital role in the ecosystem by potentially providing essential nutrients, such as vitamins B₇, B₁₂, and heme, to auxotrophic microbial groups. Overall, our findings contribute to understanding the molecular mechanisms underlying the action of cyanobactericidal bacteria against Microcystis and shed light on the ecological significance of the genus Paucibacter.

• Ocean and Polar Research
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• v.35 no.4
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• pp.299-312
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• 2013

This study analyzed the species composition and density of a macrobenthic community according to variations in the thermal discharge volumes of a nuclear power plant before, during, and after the shutdown of the nuclear power plant during two periods. In this study, 369 macrobenthic fauna species were collected, and their mean density was 1,712 ind. $m^{-2}$. The number of species and diversity of macrobenthic fauna decreased with distance from the thermal discharge area, regardless of whether the nuclear plant shutdown or not. Many macrobenthic taxa appeared near the thermal discharge area, but polychaetes species were more prominent in outer areas than at the discharge area. The density of macrobenthic fauna decreased with distance from the thermal discharge area during a plant shutdown in the fall of 2011, but increased, except at two sites, near the discharge area in the winter of 2012. Cluster analysis indicated that the spatial distribution of the macrobenthic community changed in areas near the nuclear power plant after a shutdown period; that is, the station group I, in areas near the nuclear power plant, became narrower after the shutdown, but it recovered to previously occupied areas after the nuclear power plant began operating again. Opportunistic species, such as the polychaetes Lumbrineris longifolia (= Scoletoma longifolia) and Mediomastus californiensis, which were present in high densities near thermal discharge areas, decreased after the shutdown but recovered after the plant re-opened. The number of species and diversity of the macrofauna and the density of dominant species showed a significant correlation with temperature, except in winter periods. The results of this study revealed that changes in the amount of thermal discharge before and after the shutdown of a nuclear power plant could exert an influence on the structure of macrobenthic community within the thermal discharge areas depending on the season.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.5
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• pp.84-101
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• 2004

This study presents an ecological management plan for wildbird habitat conservation, an nature-friendly enhancement of bio-diversity using the riverside of the Tancheon Ecosystem Conservation Area in Seoul by analyzing environmental and ecological characteristics. As a result of analyzing actual vegetation, vegetation type was classified into 34 types. Humulus japonicus association covers an area of 441,568.6㎡(31.44％), and Artemisia princeps var. orientalis association covers an area of 89,690.1㎡(6.39％). Sandy plain as valuable wildbird habitat covers an area of 89,965.9㎡(6.4％). 125 taxa including 34 families, 93 genera, 107 species, and 18 varieties were recorded and the number of naturalized plants were 41 taxa at the survey site. Total naturalized index(NI) and urbanized index(UI) were recorded as 32.8％, and 15.5％. As a result of analyzing the herb plants association structure by surveying 8 belt-transects, the humid native plants was dominant in the partially adjacent revetment edge and damp riverside. On the other hand, naturalized plants was so extensively dominant that it was necessary to establish an ecological management plan. The observed wildbirds belonged to 50 species, 6,118 individuals, and 7 restricted species by law, which were Accipiter gentilis, Falco tinnunculus, Buteo hemilasius, and Buteo buteo. Oriolus chinensis,Hirundo rustica, and Alcedo atthis. The ecological administration plan for Tancheon Ecosystem Conservation Area as follows: in ecological land-use planning, the conservation area(695,518.5㎡) has native woody and herb vegetation and sandy plain with water as an wildbird habitat. The restoration area(653,702.7㎡) has a naturalized plants distribution are with artificial revetment. The nature-friendly Riverside Area(55,414.9㎡) was an easily approached area with damaged riverside vegetation, and a safe area to wildbird habitat. In riverside restoration planning, the artificial riverside should be restored to its natural riverside vegetation, and the artificial embankment should be restored with edge shrubs for wildbird habitat or revegetated for natural riverside landscape. For naturalized plants management planning, we selected naturalized plant species to be weeded out, and suggested an application method for ecological management.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.94-106
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• 2008

As populations inhabiting in natural ecosystem are fragmented by artificial barriers and habitats are destructed by development, extinction possibility of species is getting higher. It is necessary to design and to manage conservation areas and corridors considering animals' movement and migration for sustainable species diversity in present circumstances. 'Least-cost modeling' is one commonly employed approach in which dispersal costs are assigned to distinct habitat types and the last-costly dispersal paths among habitat patches are calculated using a geographical information system (GIS). This study aims to design ecological corridor using least-cost path method and to apply it to a regional ecological network considering movability of medium-large size mammals. This study was carried out over the metropolitan area, which has been deforested by rapid urbanization. Nevertheless there is connected with Gangwon province, Baekdudaegan mountain range and DMZ, considered where many forest species can migrate to this region. This study employs such an approach to develop least-cost path models for medium-large size mammals, have inhabited for this entire region. Considering those species, two forest areas as a source of species supply and forest areas more than 1,000ha are selected as focal forest areas. Movement and migration paths from species supply sources to focal forest areas are calculated by applying landscape permeability theory using land cover map, road density map and land slope map. Results showed least-cost paths from species supply sources to focal forest areas on two species. Wildcat and roe deer are different in some least-cost paths caused by their landscape permeability but paths show generally same specifics. The result of considering regional distribution of expected movement and migration paths to regional ecological network, low altitude mountains of western metropolitan area are evaluated important area for species connectivity. In national or regional levels ecological connectivity is essential to promote species diversity and to preserve integrated ecosystem. This study concludes that developing least-cost models from similar empirical data could significantly improve the utility of these tools.

• Journal of Wetlands Research
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• v.22 no.4
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• pp.286-294
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• 2020

This study aims to economically evaluate rice production and various ecological services provided by organic rice paddy carrying out rice-fish mixed farming. It was also conducted to find a stable structure for increasing the income of rice-producing farmers and promoting ecological services by evaluating the economic feasibility of organic rice paddy for rice-fish mixed farming. As a result of the analysis of expected effects by ecological service functions according to the types of agriculture in the rice-fish mixed farming, general conventional paddy fields were evaluated to have an effect of continuously decreasing biodiversity such as amphibian reptiles, aquatic insects, bird habitats, experience and ecological education, and vegetation diversity, while the biodiversity of organic and rice-fish mixed paddy fields was assessed to increase. As a result of evaluating the economic value, as the area for fish production increases compared to the common practice and organic paddy fields, rice production decreases, but fish production increases and total income was analyzed to increase. In addition, if the value of ecosystem service functions is assessed in the future, it will increase further. It is hoped that these findings will be used as basic data for solving oversupply problems in the rice industry, preserving safe farm income, and improving sustainable farming and ecosystem service functions.

• Korean Journal of Environment and Ecology
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• v.16 no.2
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• pp.195-216
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• 2002

The flora of Ulleung island was summarized as 975 taxa with 122 families, 465 genus, 762 species, 5 sub-species, 178 varieties, 21 forms, and 9 hybrids. This extent of plant diversity of the island ecosystem was modified from the field surveys by the authors adding the number of 627 taxa; 109 families, 355 genus, 526 species, 2 sub-species, 89 varieties and 10 forms, and Considering the aspects of geographical distribution of the island, the flora showed much closer to the Korean penninsula than that of the Japanese Archipelago. An action plan including intensive conservation and management both for habitat and plant to conserve the island ecosystem should be prepared. The naturalized plants is expanding gradually due to the increase of the tourist. The Ulleung island ecosystem should be conserved as the Protected Area, which is enlarged habitat compared with the present legal conservation actions.