• 환경생물
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• 제40권2호
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• pp.172-186
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• 2022

본 연구에서는 2019년~2020년 2년 동안 양재천과 여의천을 대상으로, 이화학적 수질항목(17항목)과 함께 저서동물지수와 우점도지수 및 다양도지수 등의 군집지수와 연계하여 두 하천의 생태건강성을 평가하였다. 또한 저서동물 생물지수의 현장 적용성 평가 및 및 두 하천 간 저서동물 분포특성을 통계적으로 비교하기 위하여 각각 상관분석(correlation analysis)과 비계량적 다차원척도법(nMDS, nonmetric multidimensional scaling)을 활용하였고, 이를 통해 도심하천의 하천생태계 현황을 진단하는 기초자료를 제공하고자 하였다. 조사 결과, 양재천(주암교, 보도교, 대치교)은 총 39종, 3,787개체가 출현하였으며, 양재천 수질(BOD, TOC, TP 기준)은 II등급(약간 좋음) 이상이며, 저서동물을 이용한 BMI는 모든 지점에서 C등급(보통)으로 나타났다. 여의천(상류, 새원교, 여의교)은 총 51종, 4,199개체가 출현하였으며, 여의천 수질(BOD, TOC, TP 기준)은 양재천과 유사하게 II등급(약간 좋음) 이상으로, BMI는 상류 및 새원교 모두 B등급(좋음), 여의교는 C등급(보통)으로 나타나는 등 전반적으로 양재천과 여의천 모두 수질 및 하천 환경상태는 유사한 것으로 확인되었다. 특히 저서동물 분포상태를 비계량적 다차원척도법으로 분석한 결과에서도 두 하천 간의 유의미한 차이를 볼 수 없었으며(p=0.1491), 이때 수온과 DO 환경인자가 두 하천에서의 저서동물 분포와 상관성이 높은 것으로 나타났다. 저서동물 생물지수와 주요 수질항목과의 상관분석 결과, 풍부도지수와 저서동물지수가 현장 수질평가에 활용될 수 있을 것으로 확인되었다.

• Journal of Plant Biotechnology
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• 제4권2호
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• pp.53-58
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these "environmental or abiotic stresses", which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity, In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.n factors.

• 생태와환경
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• 제57권2호
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• pp.111-122
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• 2024

Zooplankton biomass is essential for understanding the quantitative structure of lake food webs and for the functional assessment of biotic interactions. In this study, we aimed to propose a biomass (dry weight) estimation method using the body length of cyclopoid copepods. These copepods play an important role as omnivores in lake zooplankton communities and contribute significantly to biomass. We validated several previously proposed estimation equations against direct measurements and compared the suitability of prosomal length versus total length of copepods to suggest a more appropriate estimation equation. After comparing the regression analysis results of various candidate equations with the actual values measured on a microbalance-using the coefficient of variation, mean absolute error, and coefficient of determination-it was determined that the Total Length-DW exponential regression equation [W=0.7775×e^2.0183L; W (㎍), L (mm)] could be used to calculate biomass with higher accuracy. However, considering practical issues such as the morphological similarity between species and genera of copepods and the limitations of classifying copepodid stages, we derived a general regression equation for the pooled copepod community rather than a species-specific regression equation.

• Journal of Plant Biotechnology
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• 제44권3호
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• pp.220-228
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• 2017

식용작물, 사료, 잔디를 포함하는 모든 작물은 건조, 염, 저온, 고온 등의 여러 가지 환경스트레스의 영향을 빈번히 받기 때문에 작물의 생산성이 떨어지게 된다. 식물은 환경스트레스 상황에서 스스로 벗어날 수 없다. 따라서 식물은 환경 스트레스를 극복하는 방향으로 진화하였다. ARF, ABI3, NAC, HSF, WRKY 같은 환경 스트레스에 반응하는 유전자들이 식물에서 보고되었다. 이 유전자들은 환경스트레스에 반응하는 전사인자로, 식물의 스트레스반응 경로에 연관되어 있다. OsWRKY76의 경우에는 저온 및 병원균에 대한 내성을 증가시켰고, AtWRKY28 의 경우 여러 가지 환경스트레스에 관련이 있는 것으로 보고되었다. 들잔디는 정원이나 골프코스에서 가장 흔하게 사용되는 잔디이다. 하지만 들잔디에서는 아직 WRKY 유전자가 알려지지 않았다. 본 연구에서는 들잔디로부터 1개의 WRKY domain을 포함하는 ZjWRKY3, ZjWRKY7 를 분리하였다. ZjWRKY3과 ZjWRKY7은 저온, 건조, 염 스트레스에 발현이 증가하였다. 들잔디의 갈색퍼짐병을 일으키는 R. solani의 감염이 ZjWRKY3과 ZjWRKY7의 발현을 증가시켰다. 또한 ZjWRKY3, ZjWRKY7이 Zjchi 유전자 promoter의 W-box에 결합하여 전사를 조절한다는 사실을 확인 하였다. 따라서 ZjWRKY3, ZjWRKY7 유전자는 전사인자로서 환경스트레스 및 병원균 관련 하위 유전자들을 조절할 것으로 예상된다.

• 한국환경과학회지
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• 제12권12호
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• pp.1215-1225
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• 2003

The purpose of this research was to investigate the characteristics of urban ecotopes and to classify ecotopes systematically from them. Total of 15 characteristics for classification of ecotopes were selected, and there were categorized 3 factors, that is abiotic, biotic and anthropological factors. The ecotope types in the study area were classified into 67. The classification of ecotope was made with SPSS for Windows Version 10.0 on the basis of the 15 characteristics. As the results of cluster analysis using the average linkage method between groups, groups of ecotope type were divided into 15 clusters. It was known that there was not a great difference in an affinity as the result of overlapping the maps of ecotope type and land use type. This research suggested characteristics for classification of ecotopes, but there was a limit to Set the objective method for grade classification because of lacking in the basic data, the research of characteristics will be accomplished continuously.

• 한국환경과학회지
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• 제4권3호
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• pp.177-186
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• 1995

The seasonal changes and composition of phytoplankton of the Choonsan reservior were studied from November 1990 to October 1991. 195 taxa which belong to 65 genera, 150 species, 40 varieties and 1 forms were identified. Species number during summer monthes was higher than that of other seasons. Standing crops of phytoplankton were varied from $7.8\times10^5$ cells/l to $2.2\timesl0^6$ cells/$\ell$. The dominant species were Cryptomonas erose and Trachelomonas volvoina. Chlorophyll a contents of phytoplankton was varied from $1.36\mu\textrm{g}/\ell$ to $127.46\mu\textrm{g}/\ell$. The biotic indices of phytoplankton were very similar among three sites. Saprobien-system by index of species diversity suggests that the Choonsan reservior belongs to the oligosaprophic.

• ALGAE
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• 제17권1호
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• pp.1-9
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• 2002

Diel vertical distribution of phytoflagellates and interactions between the phytoplankton components and environmental and biological factors were studied in a small artificial pond for three days on the December 18, 1998 and April 9 to 10, 1999. The phytoplankton population was dominated by Mallomonas akrokomos of chrysophytes and Cryptomonas marssonii and Chroomonas sp. of cryptophytes. The vertical distribution of these phytoflagellates taxa exhibited clear diel migration pattern. Moreover their migration patterns are showed differential fluctuation between M. akrokomos, C. marssonii and Chroomonas sp. The later two species upward migrated in the evening as well as night, whereas the former species migrated downward. Their distinctive migration pattern was found during the night but was not observed in the morning. During daytime C. marssonii and Chroomonas sp. showed maximum density above 2 m depth but M. akrokomos below 2 m depth. The diel vertical distribution of the dominant phytoflagellates did not show significant correlation between physical, chemical and biotic factors.

• The Plant Pathology Journal
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• 제39권6호
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• pp.538-547
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• 2023

Rapid apple decline (RAD) is a complex phenomenon affecting cultivated apple trees and particularly dwarf rootstocks on grafted young apple trees. Since its first appearance in the United States, RAD has been reported worldwide, for example in Canada, South America, Africa, and Asia. The phenomenon has also been observed in apple orchards in Korea, and it presented similar symptoms regardless of apple cultivar and cultivation period. Most previous reports have suggested that RAD may be associated with multiple factors, including plant pathogenic infections, abiotic stresses, environmental conditions, and the susceptibility of trees to cold injury during winter. However, RAD was observed to be more severe and affect more frequently apple trees on the Malling series dwarf rootstock. In this study, we reviewed the current status of RAD worldwide and surveyed biotic and abiotic factors that are potentially closely related to it in Korea.

• 환경영향평가
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• 제8권2호
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• pp.45-51
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• 1999

Emergy concept was used to evaluate the contributions of a dam construction to the real wealth of our economy. A dam that is proposed as a multi-purpose dam was used to illustrate emergy evaluation methodology. Models for emergy evaluation were constructed with energy systems language, a symbolic modeling language which presents network properties of systems holistically. Water supply was the most important contribution in terms of emergy, which reflects that the dam is proposed for stable water supply to a local region. Generation of electricity was the second in emergy benefits of the dam. Emergy costs were more evenly distributed among the costs which would occur as a result of the dam construction. Emergy yield ratio was 1.30 if sediments are not included, and 1.15 if sediments are included, which results in net yield in both cases. The ratio would, however, fall below 1.0 if rare species within the system boundary are lost as a result of the dam construction because of the high emergy value included in biotic species, which means that emergy costs will be greater than emergy benefits. This study illustrated a new methodology in environmental impact assessment to better manage our environments in an age of diminishing resources.

• 환경생물
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• 제21권3호
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• pp.223-233
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• 2003

본 논문에서는 하천생태계의 환경평가 기법과 생물다양성 관리시스템을 개발하여 한국의 하천에 적용한 사례를 소개하였다. 전국 하천에서 장기간 수집된 조사자료와 문헌자료 뿐만 아니라 북한강 수계의 일련의 하천들을 대상으로 종합적으로 실시한 야외조사를 바탕으로 하천생태계의 환경과 생물다양성에 대한 조사연구의 체계를 고찰하였고, 한국 하천의 주요 환경훼손 유형을 분류하였고, 하천자연도등급 간이평가표를 작성하여 제시하였으며, GIS를 적용한 하천생태계의 생물다양성 관리시스템에 사용될 환경 및 생물 요인의 속성자료 목록을 제시하였다. ArcView와 GEUS 프로그램을 이용하여 구축한 상기 생물다양성 관리시스템을 한국의 전형적인 중규모 하천인 가평천에 적용하였다.