• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.197-206
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• 2001

The depletion of stratospheric ozone is regarded as a major environmental threat to plant growth and ecosystem. The ozone depletion has caused plants to be exposed to an increased penetration of solar ultraviolet-B (UV-B) radiation in the 280-320 nm wavelength range. Enhanced UV-B radiation may have influence on plants biological functions in many aspects including inhibition of photosynthesis, DNA damage, lipid peroxidation, changes in morphology, phenology, and biomass accumulation. To cope with the damage by UV radiation, plants have evolved to have protective mechanisms, such as photorepair, accumulation of UV-absorbing compounds, leaf thickening and activation of antioxidative enzymes. The objective of this review is to address the effects of enhanced UV-B on plant growth, UV-B action mechanisms and protection and protection mechanisms in plants.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.317-322
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• 2002

농가보급형 마늘쪽 분리기 개발을 위하여 마늘의 품종별 기하학적 특성을 분석하고, 나선 부착 원추 드럼식 마늘쪽 분리기를 제작하여 성능시험 및 농가 현장시험한 결과를 요약하면 다음과 같다. 1)종구용 통마늘의 크기를 조사한 결과 직경은 의성, 무안, 자봉이 각각 44.3, 51.9, 60.2mm로 나타났다. 2)통마늘의 최대 압축력 및 마늘쪽의 생물체항복 강도를 시험한 결과 수평방향 최대 압축력은 의성, 무안, 자봉마늘이 각각 185.1, 145.8, 148.5N이고, 마늘쪽의 생물체 항복강도는 의성, 무안, 자봉마늘이 각각 272.4, 336.2, 413.2N/$cm^2$로 통마늘은 의성종이 단단 하나 마늘쪽은 무안이나 자봉마늘에 비해 단단하지 않은 것으로 나타났다. 3)나선부착 원추 드럼 및 경사원통식 마늘쪽 분리장치를 제작하여 성능시험한 결과 1쪽 분리율이 의성, 무안, 자봉마늘에서 각각 58.2, 64.7, 95.2%이고, 손상율은 각각 2.0, 2.4, 1.9%이었으며 작업능률은 시간당 210kg(약 60접)이었다. 4)시작기를 전남무안의 재배농가에서 현장 시험한 결과 1쪽분리율은 75.9%, 손상율은 0.8%, 파종 후 출현율이 94.3%로 농가적응성 및 실용성이 높은 것으로 판단되었다.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.575-581
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• 2018

The relationship between the body size of species and the environment has been an active research subject for many years. Until recently, studies had focused on the relationship between the body size and environment based on the ecogeographic rule for various animal groups. In this study, we examined the relationship between body size of Hyla japonica and the habitat environment in Jeju island located at the southernmost part of the Korean peninsula. We collected H. japonica from three breeding sites, Cheonji, Bonggae, and Aewol, and measured SVL, BW, and HW of the species. We also measured the altitude, longitude, latitude, annual mean temperature, and annual mean precipitation of each site to analyze the relationship between the body size and the habitat environment. The analysis results showed that there was the clear difference of the body size according to the habitat and the body size in Aewol was significantly bigger than others, while the body size in Cheonji was the smallest. The altitude was the most important environmental variable and showed a positive correlation with body size. The body size of H. japonica increased as the altitude increased, and this results were consistent with Bergmann's rule, one of the biological laws related to body size. In conclusion, the environment could affect the body size of H. japonica, and the body size has a certain direction according to the environment.

• Ecology and Resilient Infrastructure
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• v.10 no.4
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• pp.171-183
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• 2023

Estuarine wetlands, which form a distinctive brackish water zone, serve as important habitats for organisms that have adapted to and thrive in this environment. Nonetheless, excessive development and utilization result in artificial disruptions that alter the distinctive functions and attributes of estuarine wetlands. To collect the basic data for the conservation of estuarine wetlands with excellent ecosystems, we investigated the vegetation distribution characteristics and biota status of the Taehwagang River Estuarine Wetland. Data from vegetation surveys have shown that 25 plant communities of six physiognomic vegetation types, including willow vegetation, lotic and lentic herbaceous vegetation, floating/submerged vegetation. In the upper reaches, where topographical diversity was high, various types of wetland vegetation were distributed. In terms of biodiversity, a total of 696 species, including 7 endangered wildlife species, were identified. Due to good ecological connectivity, tidal rivers are formed, brackish water species including various functional groups are distributed around this section. The inhabitation of various water birds, such as diving and dabbler ducks, were confirmed according to the aquatic environment of each river section. The collection of ecological information of the Taehwagang River Estuarine Wetland can be used as a framework for establishing the basis for conservation and management of the estuarine ecosystem and support policy establishment.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.2047-2058
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• 2000

The effects of operating parameters on performance of upflow anaerobic sludge blanket(UASB). anaerobic filter(AF), and two-stage anaerobic sludge bed filter (ASBF) bioreactors in treating swine wastewater were evaluated by operating the lab-scale bioreactors upto hydraulic retention time(HRT) of 1 day and organic loading rate (OLR) of $5.1kg-COD/m^3{\cdot}d$ for 200 days. Swine wastewaters of which characteristics were affected by types of hog raising and seasons contained high concentrations of COD, SS, and ammonia. Inoculation of the bioreactors with waste sludge from anaerobic treatment facility of local municipal wastewater treatment plant was effective in developing biomass in the bioreactors. Acclimation period of the bioreactors with swine wastewaters required approximately 40 days, but that for AF and two-stage ASBF, which were filled with media, was faster than VASB. The bioreactors showed high and stable COD removal efficiency of 77~91% at influent T-N concentrations of 370~800mg/L but low and unstable COD removal efficiency of 24~94% at influent T-N concentrations of 760~1,310mg/L. It is essential to remove ammonia prior to anaerobic treatment since the concentrations of ammonia in swine wastewaters showed toxic effects to methanogenic bacteria. The bioreactors were effective in treating swine wastewaters with COD removal efficiency of 78.9~81.5% and biogas generation rate of $0.39{\sim}0.59m^3/kg-COD_r$ at OLR of $1.1{\sim}2.2kg-COD/m^3{\cdot}d$: however, an increase of OLR by reducing HRT and increasing influent COD caused decrease of COD removal efficiency. The extent of decrease in COD removal efficiency was higher in UASB than AF and two-stage ASBF. AF and two-stage ASBF anaerobic bioreactors were effective in treating varing characteristics of swine wastewaters since they showed high and stable COD removal efficiency at high OLR due to effective retention of biomass by media and staging.

• 한국해양학회지
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• v.21 no.1
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• pp.13-24
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• 1986

The daily net primary production by phytoplankton in the southeastern sea of Korea in October 1985 ranged from 0.7 to 2.7 gCm$\^$-2/ d$\^$-1/ and averaged to be 1.3 gCm$\^$-2/ d$\^$-1/. Surface total chlorophyll ranged from 0.97 to 3.59mg chlm$\^$-3/. Primary production by nano-phytoplankton(〈20$\mu\textrm{m}$) ranged from 43 to 97% in the surface layer. Optimum light intensity(Iopt)was around 300 to 700${\mu}$Es$\^$-1/m$\^$-1/. Surface primary production from 9:00 to 15:00 h was evidently inhibited by strong light intensity beyond the Iopt. Phytoplankton near the base of euphotic zone(30-40m) showed extremely low Iopt suggesting adaptation to a low light environment. Since Iopt represents the history of light experience of phytoplankton at a given depth, the extent of variation in I of phytoplankton at different depth seems to be related to the in tensity of turbulence mixing in the surface mixed layer. From the present study, ammonium excretion by macrozooplankton (〉350$\mu\textrm{m}$) contributes from 3 to 19% of daily total nitrogen requirement by phytoplandton in this area. Calculation of upward flux of nitrate to the surface mixed layer from the lower layer, based on the simple diffusion model, approximates 3% of nitrogen requirement by phytoplankton. However, large portion of nitrogen requirement by phytoplankton remains unexplained in this area. In upwelling area near the coast, adjective flux might be the major source for the nitrogen requirement by phytoplankton. This study suggests that the major nitrogen source for the phytoplankton growth might come from the pelagic regeneration by nano-and micro-sized heterotrophic plandkon. Enhancement of primary production during the passage of the warm Tsushima Current is discussed in relation with nutrient dynamics and hydrlgraphic processes in this area.

• Journal of Environmental Impact Assessment
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• v.29 no.2
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• pp.79-92
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• 2020

This study aimed at analyzing the current status and further needs of ecological information which is provided with the civil servants in the process of climate change adaptation planning in ecosystem sector and at providing suggestions for future development of ecological knowledge on climate change. Therefore, we conducted a questionary survey titled as "the knowledge-base and information needs for climate change adaptation in ecosystem sector" with the civil servants who are engaged with adaptation practices in the ecology related divisions in 17 regional local governments (RLG) and the affiliated basic local governments (BLG) in Korea. As a result, the characteristics of ecological information which is applied in public practices was analyzed and strategies for improved utilization was suggested. 75% of the respondents (RLG 85% and BLG 72%) were aware of the relativeness between the existence and utilization of ecological information and the execution of climate adaptation practices in ecosystem sector. They were agreed with the necessity of ecological information not only in adaptation practices but also overall affairs in the ecological related division in the local government (RLG 82% and BLG 72%). The current situation of utilizing ecological information which is produced from central orlocal government to civil affairs were only represented as 64 persons (28%) in RLG and 42 persons (18%) in BLG. One of the major obstacles that the respondents confront with when applying ecological information to public practices was deficit of prior knowledge on the ecological information itself, such as awareness of the characteristics of ecological information and the link with public affairs for adaptation plans. Therefore, delivering current knowledge and ecological information on climate change by educational and promotional method is an urgent priority to the civil servant. The future needs on ecological information for local government servants were deduced as basic information on local ecosystem and applied knowledge on local development to meet the biodiversity conservation and ecosystem services at the same time. The respondents expected not only the specific guidelines for using ecological information to apply on the adaptation plans in the relevant divisions of the local governments but also the institution where the usage activation of ecological information would be operated and managed to enhance the information utilizing structure in the local government. In the nation-wide, the capacity of local governments should be enhanced with adaptation knowledge and the application of appropriate information to the public practices by central government's aiding with the better quality of information, its public promotion, and the applicability to civil affairs.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1989-1993
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• 2009

댐의 조절방류가 하류 하천생태에 미는 영향은 매우 복잡하다. 하류생물상에 미치는 영향은 댐에서의 거리, 유황의 변화크기에 따라 달라진다. 흐르는 물에 서식하는 물고기는 좋아하는 수심, 유속 및 하상재질 등을 이용하여 살아간다. 다만 생물상은 주변환경에 적응하거나 변화하는 능력이 있어 댐의 조절방류에 의한 수생태계 변화구조를 명확히 해석하기는 불가능하다(Power et al., 1988). 댐에 의한 일정방류는 생물다양성을 감소시키며, 보다 변동성이 큰 방류하천은 하천, 연안 및 생물상 변화 유도에 긍정적인 것은 사실이다. 또한 큰 규모의 홍수파는 하천지형의 동적활동을 촉진시키며, 이는 하천을 터전으로 서식하는 동물상을 위한 생태학적 여건을 개선시켜 주게 된다. 이는 주변 식생의 생태적 조건 변화에 도움을 주기 때문에 적어도 1년에 2번 정도의 홍수파방류는 하천주변 서식처의 다양성 변화에 필요한 것으로 보고되고 있다(Kondolf and Wilcock, 1996). 최근들어 댐 하류하천의 생태복원을 위해 연속적인 홍수파 방류의 중요성이 강조되고 있는데(Stanford et al, 1996) 자연하도에서 댐과 같은 구조물에 의한 유량조절은 하중도나 사주 등을 발달시키고 사주에서는 두꺼운 식생층이 형성될 뿐만아니라 수목군의 현저한 출현을 보여준다. 이렇게 사주나 식생이 고착됨에 따라 이의 저항을 피해가는 수로가 형성되고 저수로 구간외에서는 식생의 발달이 더욱 왕성해져 그 면적이 확대되고 있다. 결국 사주와 사주가 식생으로 연결되고 여기에 수목이 자라면서 웬만한 홍수에도 파괴되지 않는 거대한 식생대가 출현하게 되는데 우리나라에서도 많은 하천에서 볼 수 있는 현상이다. 또한 댐에 의한 퇴사의 차단은 하천지형의 불균형을 초래하고 식생의 발달과 함께 저수도부는 좁아지고 세굴에 의해 깊어지는 현상을 보인다. 이와같은 현상들은 수문특성의 변화에 의하여 결국 댐의 조절방류에 의한 수문 변화는 하천지형의 변화를 유발하고 하천지형의 변화는 하천환경에 변화를 미치게 된다. 본 연구에서는 실제적으로 댐이 건설된 지역에서 조사된 몇몇의 자료를 분석하여 댐건설후에 나타나는 부정적 영향을 최소화하기 위한 바람직한 댐운영방안을 제시하고자 한다.

• Ocean and Polar Research
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• v.29 no.3
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• pp.263-271
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• 2007

The survival strategies of polar organisms at permanently or extremely cold temperatures and their application to cryobiology were reviewed here. In addition, ongoing studies on psychrophiles also were described. Psychrophiles are extremophiles that can grow and reproduce in cold temperatures, typically at -10 to $20^{\circ}C$. These organisms developed various mechanisms of adaptation to extremely cold environments. Polar organisms cope with these extreme physicochemical conditions using strategies such as avoidance, protection and partnership with other organisms. Understanding on the strategies adopted by polar organisms may provide insight on the physiological process that cells can go through during freezing. Cryopreservation may be able to take advantage of the findings described above. Currently, genomes of many cold-loving organisms have been sequenced and comparative genomics has revealed, at a molecular level, the characteristics of these organisms. The investigation of microorganisms on the polar glaciers may expand our understanding on the origin of life on Earth and other planets.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.113-117
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• 2017

Bioremediation is a technique using microorganisms to clean up contaminated pollutants including heavy metals. It is well known that yeasts have a high capacity to remove a wide range of metals by biosorption. Therefore, this study was focused on to obtain yeast mutant that has strong tolerance to zinc (Zn), one of representative heavy metals. The Zn resistant yeast mutant (ZnR) was induced and isolated by growing yeast cells in media containing 1 mM $ZnCl_2$ and gradually increasing the concentration until 80 mM $ZnCl_2$, in which cells were adapted and survived. The induced ZnR cells showed strong tolerance to Zn stress compared with control cells. Moreover, the ZnR cells showed increased tolerance to cadmium and nickel stress but decreased tolerance to copper stress. The increased tolerance of ZnR cells to Zn stress was due to mutation of genes. This study can be useful in bioremediation of heavy metals as the metal tolerant microorganism was artificially induced in short time.