• 한국습지학회지
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• 제9권2호
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• pp.57-69
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• 2007

본 연구는 마산만에서 육상기원 오염부하와 퇴적물로부터의 부하에 의한 해수 수질의 응답특성과 환경용량을 2002년 하계의 관측 자료를 바탕으로, 생태계 모델링을 이용하여 산정하였다. 만 내측의 잔차류는 0.1~1.5cm/s의 크기로 비교적 현상과 유사하게 재현되었는데, 표층에서는 잔차류가 남향으로 저층에서는 북향류를 이루고 있어서, 육상으로부터 유입된 오염물질이 쉽게 만 외부로 빠져나가는 것이 힘들다. 모델링결과 COD 분포는 육상오염부하가 큰 만 내측에서 3 mg/L이상의 높은 값을 나타내고 있다. 목표수질 해역 I등급(COD 1 mg/L)을 달성하기 위한 오염원별 삭감 부하량은 유기물(COD)과 영양염을 80%이상 삭감해야하는 것으로 나타났다. 또한, 해역 II등급(COD 2 mg/L)을 달성하기 위한 오염원별 삭감 부하량은 유기물(COD)과 영양염을 50%이상 삭감하여야 하는 것으로 나타났다. 각각의 경우 COD의 환경용량은 2.32 ton/day와 7.16 ton/day로 나타났다.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.27-27
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• 2003

Lake Texoma is located on the border of southern Oklahoma and northern Texas. It has 93,000 surface acres, and is a focus of the recreation, and farming industries in the region. There are potential stressors around the Lake Texoma watershed that may cause adverse ecological effects in the lake. System assimilative capacity (SAC) is the ability of abiotic and biotic processes to atteuniate the stressors. SAC Exceeded indicates potential of occuring adverse eco-effects. A number of representative chemical release sites and stressor sources in the surrounding watershed were characterized, and several impact sites having stressors sources, such as being near agriculture, landfills, housing areas, oil production fields and heavy use recreational activity, were selected for surface water, sediment, and groundwater monitoring. A paired reference site, having similar physical characteristics as its impact site, was also chosen based on its proximity to the impact site. Lake water samples were collected at locations identified as marina entrance, gasoline filling station, and boat dock at five marinas selected on Lake Texoma from September 1999 to December 2001. Paired water and sediment samples were also collected. Groundwater samples were collected at about 70 producing monitoring wells. Water quality parameters measured were inorganics (nitrate, nitrite, orthophosphate, ammonia, sulfate, and chloride), dissolved methane, total organic carbon (TOC) (or DOC), volatile organic compounds (VOCs) such as methyl tert-butyl ether (MTBE) and BTEX, and a suite of metals. Biotic communities were evaluated at impact and reference sites. Five basic components were measured; two terrestirial components (plants and bird comminitires) and three aquatic components (benthic inverbrates, litteral-zone fishes, ecosystem attribures). Potential impacts to these comminites were evaluated.

• 한국조경학회지
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• 제43권6호
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• pp.109-126
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• 2015

본 연구는 백사실계곡 생태 경관보전지역의 생물다양성 확보와 건강한 생태계 유지에 필요한 정밀 자료를 구축하고, 보전지역 특성에 맞는 생태적 관리계획을 제시하고자 하였다. 연구기간은 2010년 4월부터 2013년 5월까지이다. 백사실계곡은 최근 시민들의 이용 증가와 외래식물 식재 및 확산이 되고 있어 생태계 교란이 가속화 되고 있다. 주요 연구내용은 보호지역 관리시스템 고찰, 유역권 차원의 생태적 관리 필요성 고찰, 관리계획 수립 체계 설정, 사례 대상지 현황조사 및 분석, 위협요인 도출, SWOT 분석을 통한 목표 설정, 관리 전략, 관리계획 수립이었다. 현황조사 항목은 자연기반 환경, 동 식물 현황, 이용 환경으로 구분하여 파악하였다. 백사실계곡 생태 경관보전지역의 생태적 관리계획의 목표는 양서류의 안정적인 산란 및 서식을 위한 유역권 관리, 까막딱다구리의 영구적 서식 유도를 위한 산림 식생 보전 및 복원, 대경목 느티나무 군락 경관 보전을 위한 기반 환경 관리, 보호생물의 안정적 서식을 위한 이용자 관리로 설정하였다. 세부 관리계획 내용으로 보전 계획은 상류부 점 비점오염원 관리, 자생식물 생육환경 확보, 안전한 양서류 서식처 확보, 주요 야생조류 서식지 확보를 제시하였고, 복원 계획은 인공림의 자연림 복원, 자생초본 및 외래초본 관리, 훼손된 숲길 복원을 제시하였다.

• Mycobiology
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• 제36권1호
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• pp.34-39
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• 2008

Schizophyllum commune is an edible and medicinal mushroom widely distributed in the world. The optimal growth conditions for the mycelia of 10 strains of the fungus were investigated. The temperature suitable for the mycelial growth and density was obtained at $30{\sim}35^{\circ}C$. Among the tested conditions, the minimum mycelial growth was found at $15^{\circ}C$. In case of pH, the most favorable growth was found at pH 5. The results indicated that this mushroom well adapted to high temperature and low pH for its mycelial growth. Considering growth phenotype of mycelia, Hamada, Hennerberg, PDA and YM were the most suitable and Lilly, Glucose triptone, Glucose peptone and Hoppkins were the most unfavorable among tested media for the mycelial growth of S. commune. Out of tested carbon sources, dextrin and fructose were the most suitable and lactose, mannose and sorbitol were the unsuitable for the fungus. Compact mycelial density was obtained from most of the carbon sources. Among used nitrogen sources, calcium nitrate, potassium nitrate and alanine were the most appropriate and the most incompatible were ammonium phosphate, histidine, urea and arginine for mycelial growth of S. commune on the culture media. Calcium nitrate, histidine and potassium nitrate showed moderately thin or thin, and rest of nitrogen sources showed compact or moderately compact mycelial density.

• Journal of Ecology and Environment
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• 제43권1호
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• pp.31-42
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• 2019

Background: Han River estuary is a national wetland reserve near the Demilitarized Zone (DMZ) between South Korea and North Korea. This trans-boundary estuary area has been well preserved and shows distinctive plant communities along the salinity gradient. To elucidate energy flows and nutrient cycling in this area, we studied trophic relations between the dominant sesarmid crab, Sesarma dehaani, and food sources in three wetlands with different environments along the estuarine gradients. Results: Stable isotope signatures (${\delta}^{13}C$ and ${\delta}^{15}N$) of the crabs were significantly different among the sites and body size classes. Seasonal changes in ${\delta}^{13}C$ of small crabs were distinct from those of large individuals at all the sites. The isotopic values and fatty acid profiles of the crabs were more different among the sites in September than in May. In May, large-sized crabs utilized more plant materials compared to other dietary sources in contrast to small-sized crabs as revealed by a stable isotope mixing modeling, whereas contributions to diets of crabs were not dominated by a specific diet for different body size in September except at site 1. Based on PCA loadings, fatty acid content of $18:3{\omega}3$, known as a biomarker of plant materials, was the main factor to separate size groups of crabs in May and September. The ${\delta}^{13}C$ value of sediment had high correlation with those of small-sized crabs at site 1 and 2 when 1-month time lag was applied to the value for crabs during the surveyed period. Conclusions: Based on the stable isotope and fatty acid results, the consumption habits of S. dehaani appear to be distinguished by sites and their size. In particular, smaller size of S. dehaani appears to be more dependent on fewer food sources and is influenced more by the diet sources from the sediments in Han River estuary.

• 한국환경생태학회지
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• 제28권4호
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• pp.472-483
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• 2014

도시림 개선을 위한 노력은 꾸준하게 진행되어 왔으나 사회적인 욕구를 제대로 반영하였는지에 대한 평가가 없어 향후 지속적인 개선 및 관리의 방향을 제안하기는 어려운 상태이다. 사회환경과 생물환경이 어우러진 도시림을 효율적으로 개선하기 위해서는 양적 증대 뿐만아니라 생물의 분포 및 서식, 인간의 이용성을 평가할 수 있는 연결성, 건전성, 접근성 등 질적인 측면을 동시에 고려할 수 있는 생태적 건전성에 대한 평가지표의 필요성에 따라 연구를 진행하였다. 연구는 생태적 건전성 평가시 중요한 항목에 대한 상대적 중요도 평가, 문헌고찰을 통한 세부 지표 선정, 타당성 검토의 체계를 갖는다. 결과적으로 도시림은 자연림과는 다른 기능이 존재한다는 전제로, 도시림 평가는 고유의 기능인 생태성 뿐만아니라 인간의 간섭을 고려할 수 있는 사회성, 관리성이 충분하게 고려되어야 하나 중요도에 대한 설문조사 결과 생태성이 다른 가치에 우선하는 것으로 나타났다. 이에 생태적 건전성을 평가할 수 있는 세부지표를 선정하였는데, 식생관련 지표로는 희귀성, 훼손잠재성, 자연성, 면적, 다양성, 발생기간, 야생조류관련 지표로는 숲 발달정도, 면적을 추출하여 분산분석을 실시한 결과 안정성, 자연성, 다양성, 잠재성, 서식가능성이 평가지표로 선정되었다.

• Journal of Ecology and Environment
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• 제37권4호
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• pp.225-229
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• 2014

Feeding behavior of Temora turbinata was investigated through laboratory experiments with special emphasis on its food preference and consequent clearance rate on diatom and microbial components given as common natural food assemblage of coastal area (Uchiumi, Uwa Sea, Japan). Among available prey items, T. turbinata showed the highest clearance rate for Thalassiosira spp. ($0.23{\pm}0.08L\;Temora^{-1}day^{-1}$) followed by Chaetoceros spp. ($0.11{\pm}0.03L\;Temora^{-1}day^{-1}$), but clearance rates for other diatom, Nitzschia spp. was lower (0.03 to $0.07L\;Temora^{-1}day^{-1}$). Bacterial abundances showed no response against 24-h feeding of T. turbinata. Feeding of T. turbinata on heterotrophic nanoflagellates (HNF) was apparent when clearance rates of T. turbinata on diatoms were relatively low, but T. turbinata did not consume HNF as well as ciliates with Thalassiosira spp. of which clearance rate was highest. The results suggest that HNF and ciliates are possible supplementary prey item for T. turbinata, but their contribution as food sources can be limited by the presence of other prey items such as preferable diatom species.

• Journal of Ecology and Environment
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• 제43권2호
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• pp.191-201
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• 2019

Macroecologists and biogeographers continue to predict the distribution of species across space based on the relationship between biotic processes and environmental variables. This approach uses data related to, for example, species abundance or presence/absence, climate, geomorphology, and soils. Researchers have acknowledged in their statistical analyses the importance of accounting for the effects of spatial autocorrelation (SAC), which indicates a degree of dependence between pairs of nearby observations. It has been agreed that residual spatial autocorrelation (rSAC) can have a substantial impact on modeling processes and inferences. However, more attention should be paid to the sources of rSAC and the degree to which rSAC becomes problematic. Here, we review previous studies to identify diverse factors that potentially induce the presence of rSAC in macroecological and biogeographical models. Furthermore, an emphasis is put on the quantification of rSAC by seeking to unveil the magnitude to which the presence of SAC in model residuals becomes detrimental to the modeling process. It turned out that five categories of factors can drive the presence of SAC in model residuals: ecological data and processes, scale and distance, missing variables, sampling design, and assumptions and methodological approaches. Additionally, we noted that more explicit and elaborated discussion of rSAC should be presented in species distribution modeling. Future investigations involving the quantification of rSAC are recommended in order to understand when rSAC can have an adverse effect on the modeling process.

• 한국해양공학회지
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• 제25권4호
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• pp.54-58
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• 2011

The need and importance of developing and utilizing the oceans, not only as sources of renewable energy and mineral resources, but also as countermeasures to global warming such as for CCS (carbon capture and storage), have continued to increase, especially in countries with limited land areas and resources. Therefore, it is necessary to assess the sustainability of an ocean utilization technology or system not only from an economic point of view but also from an ecological one. For this purpose, it might be effective to develop a comprehensive evaluation method and/or index, by which the assessment of and decisions about a technology and system can be made more objectively. It would also be useful to have an environmental simulation model, which was developed and reported in a previous research. The aim of this study was to modify a reasonable and quantitative index, with which a comprehensive evaluation system can be established, to assess environmental sustainability and risk.

• Journal of Microbiology and Biotechnology
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• 제17권10호
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• pp.1727-1732
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• 2007

Phenylacetic acid (PAA) is produced by many bacteria as an antifungal agent and also appears to be an environmentally toxic chemical. The object of this study was to detect PAA using Pseudomonas putida harboring a reporter plasmid that has a PAA-inducible promoter fused to a green fluorescent protein (GFP) gene. Pseudomonas putida KT2440 was used to construct a green fluorescent protein-based reporter fusion using the paaA promoter region to detect the presence of PAA. The reporter strain exhibited a high level of gfp expression in minimal medium containing PAA; however, the level of GFP expression diminished when glucose was added to the medium, whereas other carbon sources, such as succinate and pyruvate, showed no catabolic repression. Interestingly, overexpression of a paaF gene encoding PAA-CoA ligase minimized catabolic repression. The reporter strain could also successfully detect PAA produced by other PAA-producing bacteria. This GFP-based bioreporter provides a useful tool for detecting bacteria producing PAA.