• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.898-905
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• 2019

As the positive feedback between the absorption of chromophoric dissolved organic matter (CDOM) and acceleration of ice melt can impact the aquatic biota and dynamic heat budget, long-term monitoring of the CDOM variation in the polar ocean is necessary. However, the monitoring of CDOM is not easy because of harsh weather and difficult access, especially in the Antarctic Ocean. Therefore, the purpose of this study was to find a suitable long-term monitoring site for CDOM variation; we selected Maxwell Bay and Marian Cove at Sejong Base and horizontal and vertical distributions of CDOM were measured. After a 72 hr time-series measurement test of the CDOM variation at Sejong Dock and Sejong Cape in Maxwell Bay, Sejong Dock was selected, as it does not haveland discharge effects. The seasonal variation of CDOM was evident and the average CDOM concentration of Maxwell Bay was comparable with the adjacent sea. The CDOM at Sejong Dock from February to November 2010 was the highest in the fall and winter and the lowest during spring and summer. Thus, based on our one-year CDOM data, we suggest that Sejong Dock in Maxwell Bay is suitable for long-term monitoring of CDOM as an indicator of photochemical and biological environmental change and an important factor in determining the heating budget in the Antarctic Ocean.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.221-226
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• 2006

In order to search anti-obesity agents, the methanol extracts of 155 herbal medicines were screened using with pancreatic lipase, which is involved in conversion of triglycerol to fatty acid. Among the tested medicinal plants, methanol extracts of Amsonia elliptica, Arecae pericarpium, Biota orientalis, Cinnamomum cassia, Curcuma aromatia, Elsholtzia ciliate, Glycyrrhiza uralensis, Mucunae Caulis, Rhus javanica, and Rubus coreanus showed potent inhibition at final concentration of $200\;{\mu}g/ml$ on pancreatic lipase activity. All of them were extracted into chloroform fraction. The relative inhibitory activities against pancreatic lipase by orlistat, the chloroform fraction of Arecae pericarpium and Cinnamomum cassia were 89, 80 and 80%, respectively. These results demonstrated that the screened medicinal plants could be develop as the effective lipase inhibitors in preventing and ameliorating obesity of human beings.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.1-9
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• 2014

Lake Suwa is a natural lake which is well-known for sightseeing and fisheries. It had suffered severe eutrophication during 1960s and 1970s with the occurrence of cyanobacterial blooms and the extinction of some benthic animals. Since 1980 water quality has been improved due to efforts of local government, scientists, and citizens. Of various methods that were attempted to improve the water quality of Lake Suwa biological methods received much attention, because it can improve the lake ecosystem integrity and fisheries in addition to the water quality. The aim of this paper is to introduce the biological methods for water quality improvement that had been employed in Lake Suwa, Japan, and their contribution to the economic benefit of local residents. Until now a significant restoration of water quality has been achieved, but there are insufficient recovery of the sediment and biota due to anoxic hypolimnion of the lake. This study proposed suspended cage culture of bivalves as a feasible method of water quality improvement. Increased grazing by bivalves will contribute to the improvement of water quality and fisheries production, which will contribute both to the ecological restoration and economy of local residents.

• Economic and Environmental Geology
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• v.37 no.3
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• pp.335-345
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• 2004

Total and extractable contents of heavy metals were measured in sediment and seafood from Bukhang and Boggil-ri tidal flats along the Mokpo coastal area, south-western part of Korean peninsular in order to assess the degree of metal pollution, metal bioavailability and metal hioaccumulation. The metal concentrations, except Pb were found to be greater than the background concentrations of sediments indicating the progress of cumulative contamination by anthropogenic origin of metals. The order of extractable metal concentrations in sediments were Mn(32-53 mg/kg)＞Zn(14-42 mg/tg)＞Cu(2.5-17.0 mg/kg)＞Pb(2.4-6.8 mg/kg)＞Cd(0.5-0.7 mg/kg). However, the amount of metals associated with extractable fraction of sediments were significantly high in Bukhang relative to Boggil-ri. Significant bioaccumulation of all metals, except Pb were observed in seaweed and benthos. The order of bioaccumulation of metals were: in concentration; all biota commonly, Mn(129-374 mg/kg)＞Zn(19-106 mg/kg)＞Cu(6-87 mg/kg)＞Cd(4.6-7.6 mg/kg)＞Pb(0.2-3.7 mg/kg), in BCF; Enteromorpha, Cd＞Mn＞Cu＞Zn＞Pb, Ilyoplax deschampsi, Cu＞Cd＞Mn＞Zn＞Pb, Urechis unicinctus, Cd＞Zn＞Mn＞Cu＞Pb. Some metal concentrations of Enteromorpha, especially Cu, Zn, weakly Pb in bukhang, Mn, Cd in boggili-ri, were correlate well with concentrations in sediment, indicating relatively more contaminated by the anthropogenic origin of metals in each tidal flat. The results clearly indicate that the seafood of bukhang, even of Boggili-ri known as clean area, are contaminated with metals.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.872-877
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• 2011

Cultivation of Korea ginseng in newly reclaimed and paddy-converted fields has been increasing, and evaluation of organic amendment effectiveness is needed in the two soil types. Soil organisms influence organic matter decomposition, and their responses to applications of organic matter were studied. De-oiled cake and compost were applied at $20Mg\;ha^{-1}$ and $40Mg\;ha^{-1}$ in both soil types. Changes in microflora were assessed by analyzing phospholipid fatty acid (PLFA). The abundance of nematodes and microarthropods was measured. Microbial PLFA indicators for microorganisms and microarthropod abundance were greater in reclaimed upland than in paddy-converted soil. There were few differences in the microflora and fauna of reclaimed uplands, regardless of treatment. In paddy-converted soil, the abundance of Oribatida was increased by the application of compost at $20Mg\;ha^{-1}$ and was correlated with PLFA indicators of fungi. The results suggested a minimal influence of organic amendments in reclaimed upland, because the organic matter content and abundance of soil organisms are low in mineral soils. In paddy-converted soil, the effects of organic amendment differ among different soil organisms, and soil properties are important mediators of the effect.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.681-686
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• 2011

The aim of this study was to investigate the distribution of soil biota across forest types and soil depths in Gwangneung Experimental Forest. We selected 5 sites, which are 3 deciduous- and 2 coniferous forests. The abundance of microflora in these areas was analyzed by the phospholipid fatty acid (PLFA) indicators, and the density of mesofauna was measured by the abundance of nematodes and microarthropods. The abundance of soil microflora was higher in the A layer than in the B layer based on the PLFA indicators, but there were no differences between deciduous and coniferous forests. Average density of nematodes was higher in the A horizon than in the B horizon. The density of fungivorous nematodes was higher in the deciduous forests. Mean densities of Collembola and Oribatida were 44% and 42% of microarthropods in soil samples, respectively. The results of microbial PLFA indicators were significantly correlated with the density of their consumers, which reflected that the food web in fungi- and bacteria-based soil developed in this forests. This study suggested that the distribution of soil organisms largely separated by soil depths and was slightly affected by the forest type in the Gwangneung Experimental Forest.

• Ecology and Resilient Infrastructure
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• v.9 no.4
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• pp.237-246
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• 2022

Owing to their high bioproductivity and unique physical environment, estuarine wetlands are gaining importance in national biodiversity management and habitat conservation. With regard to conservation and management of estuarine wetlands, this study analyzed the ecological characteristics of Gahwacheon Estuarine Wetland, an open estuary with various habitat types. Data from vegetation and biotic surveys have shown that 12 plant communities of five physiognomic vegetation types, including lentic herbaceous vegetation, halophytic herbaceous vegetation, and chasmophytic herbaceous vegetation. Due to the discharge of Namgang Dam and the effect of the tide, vegetation are distributed along the narrow waterside area. In terms of biodiversity, a total of 715 species, including 12 endangered wildlife species, were identified. Species diversity was relatively high in sections I and III where various riverbed structures and microhabitats were distributed. Due to the effect of the brackish water area following the inflow of seawater, endangered wildlife of various functional groups were also found to be distributed, indicating the high conservation value of that area. The collection of ecological information of the Gahwacheon 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 Appropriate Technology
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• v.5 no.2
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• pp.106-113
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• 2019

In order to respond to the global environmental issues, developed countries have been helped the developing countries as the Official Development Assistance (ODA). It is important to understand technology needs of the developing countries to provide the optimum solutions. In this study, the information of the environmental R&D dealing with appropriate technology were comprehensively collected based on the conducted R&D projects from the ministry of environment in Korea. The technology needs by UNFCCC (United Nations Framework Convention on Climate Change) and Korean government were analyzed named as TNA and CPS according to the target developing countries. In South-East Asia and Africa region, there were technology needs on water, biota, air, solid wastes, infrastructures and resources. And they were related to the issues such as environmental pollution, construction, climate change, biodiversity, energy and water management. The technology needs by UNFCCC and Korean government were also compared. Furthermore, the environmental R&D on appropriate technology should be focused on localization and maintenance to provide sustainable solutions to the developing countries.

• 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.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.197-203
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• 1998

Although biological metabolism in soil is very important for evaluating the soil properties, most of researches have concerned mainly about physical and chemical sides. In this study, biological characteristics were examined to demonstrate the biota in the plastic film house soils. Contents of organic matter and phosphate in soil were increased with cultivation period. ECs of soil cultivated spinach and melon were $3.59dS\;m^{-1}$ and $3.46dS\;m^{-1}$ respectively: these values were higher than that of rose and flower, which were $1.23dS\;m^{-1}$ and $1.32dS\;m^{-1}$ respectively. The population of fluorescent Pseudomonas strains of the soil cultivated flowers: $113.8{\times}10^4{\sim}129.7{\times}10^4cfu\;g^{-1}$ was higher than that of leafy vegetables: $40.7{\times}10^4{\sim}97.9{\times}10^4cfu\;g^{-1}$ and fruiting vegetables: $25.0{\times}10^4{\sim}91.7{\times}10^4cfu\;g^{-1}$. However the number of Fusarium strains of the soil cultivated with flowers: $3.8{\times}10^2{\sim}4.0{\times}10^2cfu\;g^{-1}$ was lower than that of leafy vegetables: $4.3{\times}10^2{\sim}16.3{\times}10^2cfu\;g^{-1}$ and fruiting vegetables: $7.6{\times}10^2{\sim}30.0{\times}10^2cfu\;g^{-1}$. In relation to the cultivation period, the habitation density of aerobic bacteria, mesophilic Bacillus, thermophilic Bacillus, and fluorescent Pseudomonas strains was the highest in the soil cultivated over 11 years, but diversity index showed negative correlation with cultivation period. Microbial biomass C in these soils had positive correlation with each number of microorganisms including aerobic bacteria, actinomycetes, and strains of mesophilic Bacillus as well as the total number of these microorganisms.