• Analytical Science and Technology
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• v.19 no.3
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• pp.244-254
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• 2006

Flame retardants are added to prevent catching fire and to slow down the burning process. PBDEs are known to affect thyroid hormones and hormone disruption. The aim of this study was to propose a manual for determination of PBDEs, and investigate the accumulation of PBDEs(BDE-28, 47, 99, 100, 153, 154 and 183) in fish&shellfish and human milk samples. Pre-treatment for PBDEs determination, alkali digestion and L-L(Liquid-Liquid) extraction method could be applied to fish and shellfish. When Multi-layer column was used for cleaning up the sample, 50 mL of hexane and 100 mL of hexane:dichloromethane(9:1) solutions were used for pre- and post-elution, respectively. Activated-carbon column was optimized by a 100 mL of hexane:dichloromethane(3:1). The result of fish, highest concentration was detected in flatfish, 890 pg/g(wet weight). The other side, lowest concentration was detected in pollack, 40 pg/g(wet weight). The result of breast milk, PBDEs was detected 2,580 and 3,600 pg/g(lipid weight) from breast milk of Seoul and Juju, respectively. BDE-153 and 183 were not detected in all samples. There was no difference in PBDEs level was not difference between first and second delivery. In this study, we could find that PBDEs level in Korea is lower than other countries.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.112-112
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• 2022

외래잡초인 애기수영(Rumex acetosella)는 생태계 교란종으로 생물다양성을 감소시키고, 우리나라 목초지에 우점하고 있어 큰 문제를 야기한다. 애기수영의 경우, 살초효과 및 제초활성물질인 chrysophanic acid와 catechd이 밝혀져 있지만, 톨페스큐(Festuca arundinacea)에 대한 살초 효과 연구는 미비하다. 이에 본 연구는 톨페스큐 종자에 대해 애기수영 MeOH 추출물을 처리한 Seed bioassay를 진행해 IC₅₀ 값을 구하고, 톨페스큐에 애기수영 MeOH 추출물을 경엽처리를 진행한 후 생육조사를 진행했다. Seed bioassay의 경우, petri dish 위에 톨페스큐 종자 20개가 치상하고, 애기수영 지상부 추출물과 지하부 추출물을 각각 20,000 mg L^-1, 10,000 mg L^-1, 5,000 mg L^-1, 2,500 mg L^-1 농도로 serial dilution 하여 1mL씩 분주한 뒤, 일주일 뒤에 발아한 종자에 대해 생체중을 조사하고 Prizm 프로그램을 이용해 IC₅₀을 구하였다. 경엽처리의 경우, 톨페스큐 종자 파종4주 뒤에 IC₅₀값이 더 낮았던 지상부 추출물을 100,000 mg L^-1, 50,000 mg L^-1, 25,000 mg L^-1, 12,500 mg L^-1, 6,250 mg L^-1 농도로 serial dilution 한 뒤 5mL씩 일주일 간격으로 3회 경엽처리를 진행하였고, 마지막 처리 일주일 뒤 초장, 근장, 생체중, 건물중을 조사하였다. Seed bioassay 결과, 애기수영 지하부 추출물에 대한 톨페스큐의 IC₅₀값은 3274가 나왔고, 애기수영 지상부 추출물에 대한 톨페스큐의 IC₅₀값은 2728가 나왔다. Seed bioassay 결과를 바탕으로 효과적 이 었던 지상부 추출물을 이용해 톨페스큐 경엽처리를 진행하였다. 애기수영 지상부 추출물 경엽처리 결과, 톨페스큐 초장과 생체중이 추출물 처리량이 높아짐에 따라 낮아졌으며, 100,000 mg L^-1 처리구는 Control과 비교해 유의적으로 감소하였고, 처리량이 높아짐에 따라 근장이 감소했지만, 유의적인 차이는 없었다. 그리고 건물중은 100,000 mg L^-1 처리구가 Control, 12,500 mg L^-1, 6,250 mg L^-1 처리구와 비교해 유의적으로 낮았다.

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.178-188
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• 2024

The dynamics of suspended sediment (SS) in forested catchments vary depending upon human or natural disturbances, including land use change, forestry activity, forest fires, and landslides. Understanding the dynamics of SS originating from the potential sources within a forested catchment is crucial for establishing an effective water quality management strategy. Therefore, to suggest a systematic method for interpreting SS dynamics, we evaluated the performance and applicability of ten methods for calculating the hysteresis index based on observed hydrological data and two calculation models (Lawler's method and Lloyd's method) with five sampling intervals (50th, 25th, 10th, 5th, and 1st percentiles). Our results showed that Lloyd's method, which used a sampling interval at the 1st percentile, had the largest number of analyzable runoff events and exhibited the best performance. The results of this study can contribute to quantifying the hysteresis in the relationship between discharge and SS and provide useful information for interpreting SS dynamics.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.112-121
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• 2004

A study was performed to examine the effects of UV-disinfected reclaimed water on microorganism concentration during rice culture. Four treatments were used and each one was triplicated to evaluate the changes of microorganism concentrations: stream water irrigation (STR), biofilter effluent irrigation (BE), UV-disinfected water irrigation with dose of 6 mW ${\cdot}$ s $cm{-2}$ (UV-6), and UV-disinfected water irrigation with dose of 16 mW ${\cdot}$ s $cm{-2}$ (UV-16). The indicator microorganisms of interest were total coliform (TC), fecal coliform (FC), and E. coli. The biofilter effluent from 16-unit apartment sewage treatment plant was used as reclaimed water and flowthrough type UV-disinfection system was used. Concentrations of indicator microorganisms in the treatment plots ranged from $10^2$ to $10^5$ MPN/100 mL during 24 hours after irrigation in May and June, where initial irrigation water for transplanting reparation was biofilter-effluent without UV-disinfection. It implies that initial irrigation using only non-disinfected reclaimed water for puddling in paddy field can be health-concerned because of more chance of farmer's physical contact with elevated concentration of microorganisms. The concentrations of microorganisms varied widely with rainfall, and treatments using UV-disinfected water irrigation showed significantly lower concentrations than others and their levels were within the range of paddy rice field with normal surface water irrigation. The mean concentrations of STR and BE during growing season were in the range of 4 ${\times}\;10^3$ MPN/100 mL for TC, and 2${\times}\;10^3$ MPN/100 mL for FC and E, Coli, While mean concentrations of UV-S and UV-lS were less than 1${\times}\;10^3$ MPN/100 mL for all the indicator microorganisms. Overall, UV-disinfection was thought to be feasible and practical alternative for agricultural reuse of secondary level effluent in Korea.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.396-401
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• 2020

As the world becomes more globalized, the non-native species issue has emerged as a problem that is growing internationally. In particular, the number of non-native turtles found in the wild has been increasing sharply in South Korea. At least 15 species of non-native turtles, including the red-eared slider (Trachemys scripta elegans) first imported in the 1970s, have been found in Korea. On October 15, 2019, an alligator snapping turtle (AST, Macrochelys temminckii) was found in a stream located in Gwangju city, South Korea. The discovery of AST became a big issue in South Korea as the animal is known for its large body size and aggressiveness and was featured widely in the mass media. In this study, to learn the public's perception of non-native species, we examined comments (opinions) to the online news articles about the AST. We collected 1,100 comments from the Internet news articles on the AST. Out of the 1,100 comments, 342 (31.1%) comments were related to non-native species' issues. Most of the respondents (97.7%, n=334) stated that the non-native species are a problem. Forty two comments mentioned potential threats posed by non-native species: non-native species' aggressive nature (n=11, 26.2%) and ecological disturbance (n=31, 73.8%). Lack of responsibility (n=122, 51.7%) was the major causative factor for the introduction of non-native species, and followed by indiscriminate pet trade (n=99, 42.0%), absence of relevant legislation (n=13, 5.5%), and absence of treatment (n=2, 0.8%). Animal registration (n=59, 45.7%) was the most commonly mentioned as the way to deal with the issue of the non-native species' invasion. Our results show that the public is aware of the seriousness of the invasion of non-native species, including AST. This study highlights that researchers and government officials need to consider the public's perception and opinions. We believe that our study can serve as an essential reference for the policy direction and the management of non-native species.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.3
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• pp.12-21
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• 2020

This study aims to implement the Sustainability Evaluation Framework of Korea Natural Parks to county parks in Gyeongsangnam-do, and to review the performance status of management effectiveness evaluation (MEE) and identify factors that influence the improvement of management effectiveness in protected areas. County park officers evaluated current management using this framework that was developed based on the MEE framework designed by the Korean Ministry of Environment. Among the principal values of county parks, 'natural and ecological' is indicated as the most important, followed by 'cultural and historic value' and 'leisure and recreation'. Natural disasters and climate change, visitor impact-inappropriate visitor behavior are indicated as current threats, and three county parks administrators viewed that there was no particular threat to their park. According to MEE results, the most effective management fields were 'State of cultural and historic value', 'State of leisure and recreational value', 'Current state of principal value'. The comparatively weaker fields were 'Threatened species management', 'Invasive species management', 'Management monitoring and evaluation'. The effects of sustainable management on county parks were analyzed through a regression analysis, and the influence of management factors reveal 'Annual budget', will impact attaining higher management scores. This study presents the current management information about county parks and provides support for the basis for the planning of county parks in Korea, suggesting the influencing factor.

• The Korean Journal of Ecology
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• v.22 no.3
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• pp.169-179
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• 1999

The present study was undertaken to classify and describe the spring naturalized plant communities in old-Andong city by the methodology of the ZM school of phytosociology. As a result, the vegetation was classified into the six communities and two subcommunities: A. Bromus tectorum community A-a. Bromus japonicus subcommunity, A-b. Melica onoei subcommunity; B. Poa pratensis community; C. Rumex crispus community; D. Oenothera lamarckiana community; E. Ambrosia artemisiifolia var. eiatior community; F. Rumex conglomeratus community. The total taxa of the naturalized plant communities consisted of 31 families, 86 genera, 114 species and 13 varieties. Of which the taxa of the naturalized plant species consisted of 8 families, 21 genera, 25 species and 1 variety. The result of Bray-Curtis ordination revealed that the plots suveyed were arranged according largely to the vegetation units of' the communities. Also the interspecific affinity was examined by an analysis of interspecific association and the main component species in the communities were divided into two groups. The naturalized rate was higher in the communitise affected by strong human impacts, while was lower in the communities affected relatively less by human impacts. On the other hand the seasonal changes of the communities and the naturalized rate between the spring and the autumn were investigated. Many naturalized communities present in Spring were replaced by the other native ruderal communitues in the Autumn. The naturalized rate based on the dominance was largely decreased over from the spring to the Autumn.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.785-795
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• 2018

The International Maritime Organization (IMO) has recognized the risk of hull fouling and announced '2011 Guidelines for the control and management of ship's biofouling to minimize the transfer of invasive aquatic species'and is planning international regulations to enforce them in the future. In this study, to effectively respond to future international regulation, we introduce the case of leading countries related to management of hull fouling and also investigate environmental risk assessment techniques for in-water cleaning. Australia and New Zealand, the leading countries in hull fouling management, have established hull fouling regulations through biological and chemical risk assessment based on in-water cleaning scenarios. Most European countries without their government regulation have been found to perform in-water cleaning in accordance with the IMO's hull fouling regulations. In the Republic of Korea, there is no domestic law for hull fouling organisms, and only approximately 17 species of marine ecological disturbance organisms, are designated and managed under the Marine Ecosystem Law. Since in-water cleaning is accompanied by diffusion of alien species and release of chemical substances into aquatic environments, results from biological as well as chemical risk assessment are performed separately, and then evaluation of in-water cleaning permission is judged by combining these two results. Biological risk assessment created 40 codes of in-water cleaning scenarios, and calculated Risk Priority Number (RPN) scores based on key factors that affect intrusion of alien species during in-water cleaning. Chemical risk assessment was performed using the MAMPEC (Marine Antifoulant Model to Predict Environmental Concentrations), to determine PEC and PNEC values based on copper concentration released during in-water cleaning. Finally, if the PEC/PNEC ratio is >1, it means that chemical risk is high. Based on the assumption that the R/V EARDO ship performs in-water cleaning at Busan's Gamcheon Port, biological risk was estimated to be low due to the RPN value was <10,000, but the PEC/PNEC ratio was higher than 1, it was evaluated as impossible for in-water cleaning. Therefore, it will be necessary for the Republic of Korea to develop the in-water cleaning technology by referring to the case of leading countries and to establish domestic law of ship's hull fouling management, suitable for domestic harbors.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.771-782
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• 2016

For basic information collection for the ecological management of forest vegetation in Korean island areas, forest vegetation between inhabited(Daemodo) and uninhabited(Gudo) island was classified in the Z-M phytosociological method and their ecological characteristics in terms of both floristic composition and structure analyzed. Forest vegetation of Daemodo and Gudo were divided into a total of 11 units and 8 units, respectively. Total cover and species diversity index(H') of forest vegetation showed significant differences between the two island, Daemodo has a high value in the tree layer, but, Gudo has a high value in the shrub layer. Composition of Life forms, Daemodo was N-$R_5-D_2$-e and Gudo MM-$R_5-D_2$-e. Family importance value(FIV), Daemdo has a high value in Theaceae(12.2) and Pinaceae(12.0) and Gudo in Lauraceae(16.5) and Fagaceae (11.6). The percentage of the total number of species in the family level, Daemodo is Asteraceae(4.5%) was the highest and Gudo is Liliaceae(7.3%). Indicator species of forest vegetation of the two islands, Daemodo is Nanophanerophytes(N) including Smilax china, Ligustrum japonicum and Eurya japonica was significant inicator species and Gudo is Megaphanerophytes(MM) including Dendropanax morbiferus, Castanopsis sieboldii and Actinodaphne lancifolia.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.14-28
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• 2017

Mt. Seunghak's Miscanthus sinensis community is not only a landscape resource in terms of cultural services within the Ecosystem Services but also a site that is visited by many mountaineers in autumn. As the current Miscanthus sinensis community has been experiencing a rapid decline due to Korean forest succession characteristics, ongoing artificial management is thought to be needed for landscape resource use. The purpose of this study was to determine growth environment characteristics and the cause of the rapid decline of the Miscanthus sinensis community in Mt. Seunghak, which is located inside a large city with a large scale and outstanding accessibility. As the Miscanthus sinensis community is the representative early vegetation that appears temporarily in dry, barren soil, the Miscanthus sinensis community in Korean forest succession tends to be unsustainable. As the current soil on Mt. Seunghak is inappropriately fertile for the Miscanthus sinensis community, other wetland woody plant communities are anticipated to succeed it. If Miscanthus sinensis community maintenance is needed for Miscanthus sinensis landscape scenery, various alternatives apart from overall Miscanthus sinensis community maintenance should be determined for cost-effective management. For example, while many byways toward the inside of the Miscanthus sinensis community have affected the Miscanthus sinensis community growth environment, the installation of wooden fences and ropes has been a control in approach. As a result of this positive effect, many byways toward the inside of Miscanthus sinensis community have been restored naturally. Through viewable range analysis, as good scenery sites on the observatory have a good viewable range on the main trail as well, if these scenery sites are intensively managed, effective Miscanthus sinensis ccommunity management will be done despite maintenance budget cutbacks. This study is expected to be used as a basic material regarding the alternatives for a sustained Miscanthus sinensis community and the possibility of cultivating other growth in poor soils of fallow fields and unused land.