• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.170-174
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• 2012

BACKGROUND: Inappropriate discharge of wastewaters and industrial effluents are becoming detrimental to the aquatic environment. The presence of toxic substances on wastewaters can be detected by physicochemical and biological methods. However, physicochemical methods do not give any information about biological toxicity. Therefore, in this study we tried to detect the presence of toxic substance on waters using sulfur-oxidizing bacteria (SOB) as a bioassay. MATERIALS AND RESULTS: The SOB biosensor was first stabilized using synthetic stream water and operated in both continuous and semi-continuous mode. When the SOB biosensor was operated in continuous mode, the effluent electrical conductivity (EC) stabilized at~1.72 dS/m. While in the case of semi-continuous, the EC stabilized at~0.6 dS/m. The SOB system was also operated at different reaction times to ascertain the shortest reaction time for monitoring the toxicity. Finally, the SOB biosensor was fed with nitrite as toxic substance. When 5 mg/L of nitrite was added to the SOB system, the EC decreased immediately. However, the EC recovered after few cycle. CONCLUSION: This study shows that the SOB biosensor can be used as warning system to protect aquatic environment from hazardous materials. Although SOB biosensor can not give specific information about the toxic substances, it can assess whether the water is toxic or not.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.118-127
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• 2005

The comparison of water balance and nutrient loading from paddy field with different irrigation management were carried out during 1999 ${\sim}$ 2002 at two different sites; one is irrigated with groundwater and the other is irrigated with surface water. For the surface water irrigated paddy field, irrigation was performed continuously during growing season. Whereas, initial irrigation with groundwater was applied during initial growing season, and the ponded water depth was maintained by natural precipitation since initial irrigation. The runoff frequency of groundwater irrigated paddy field was less than that of surface water irrigated paddy field. The nutrient concentration of ponded water was high by fertilization at early cultural periods, so reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Amount of irrigation water to surface water irrigated paddy field was higher than to groundwater irrigated paddy field and evapotranspiration was similar because it is influenced by climate. Overall input in and output from paddy field irrigated with goundwater were less than that with surface water. This study indicate that efficient water management can reduce surface drainage outflow, save water, and protect water quality. It might be important BMPs for paddy field.

• Journal of Environmental Impact Assessment
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• v.29 no.1
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• pp.61-77
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• 2020

In South Korea, major public waters have been systematic management under national level. Water environment network has been continuous monitoring for change of aquatic ecosystem, river and reservoir. In Water Quality Monitoring Networks, the data have been generally monitored Per eight days or month, while in Automatic Water Quality Monitoring Network the data have been monitored at daily intervals. Therefore, we were compared and analyzed water quality data between the networks using statistic method for same water quality item. Mann-kendall test results confirm that all points in Water Temperature (WT) and DO were not statistically significant. In particular, the result revealed that there is significant variation of TOC in the four different sites, TN in two different sites, TP in three different sites, WT in seven different sites, pH in two different sites between Water Quality Monitoring Network and Automatic Water Quality Monitoring Network. As a result firm LOWESS, TOC and pH clearly shows different trend. Among different sites, the water quality show the significantly positive correlations between at Sinam-Sangju2 and Namgang-Namgang4. Negative correlation significantly appeared in TP (ADD_Lower-AD1 site), TOC (DG-SG site), pH (GR-GR site), TP (JP-CN) and TN, TP, pH, EC, DO (GC-GC2-1 site).

• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.194-201
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• 2014

To elucidate which climate factors and what periods affect the time of breeding migration of Gori salamanders (Hynobius yangi), we have investigated relationships between the 5-years breeding monitoring data from 2006 to 2010 which had obtained in both natural and translocated breeding sites at Bongdae mountain, Gijang-gun, Busan-si and the matched climate data obtained from the weather station, approximately 25 km apart from the sites. Mean average and mean lowest temperatures during one month before the first breeding migration were related with the time of first female migration in the translocated site. Mean temperature variation and mean precipitation during 60~120 days before the first breeding migration affected the time of 30% male appearance at the natural site and the time of 30% female appearance at both natural and translocated sites. Climate factors were more closely related with female appearance than male and at the translocated site than at the natural site. Our results show that changes in mean temperature variation and mean precipitation rather than mean average temperature might more significantly affect the breeding migration of salamanders, female breeding migration is more closely related with climate factors, and the salamanders translocated could be more affected by climate changes than those in natural populations.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.2
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• pp.123-129
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• 2011

A study on the occurrence and movement of marine debris is required for protecting the marine environment and ecosystem from marine pollution. The aim of this study is to show annual production and movement characteristics through analysis for the flow path, composition and the sources of marine debris. This study analyzed the distribution and characteristics of marine debris collected in the region of $100\;m{\times}20\;m$($=2,000\;m^2$) at the Daekwang Beach in the Yellow Sea. During the collection period from 2008 to 2010, the total weight of the marine debris was 1,445 kg in this site. The most marine debris was plastic amounting to 46.5% of the whole collection; the rest were styrofoam(20%) and wooden material(12.6%). The amount of marine debris mused from foreign country observed 155.5 kg, more than 90% of them was plastic came from China such as buoys. Additionally, this study analyzed seasonal change if marine environment to understand occurrence amount change if marine debris. 2009 and 2010 was high occurrence ratio in season that the north wind is very strong and the occurrence rate appeared highest by 40% in the summer(July) of 2008 that appeared westbound tidal current. Overall, marine Debris mused from foreign country was high occurrence ratio in January, May and then November has a lot of quantity secondly. While, occurrence ratio was the highest by 46% summer(July) in 2008, but in 2009 and 2010 showed the lowest rate to 4%.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.327-349
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• 2010

This study was carried out to investigate the distribution of vascular plants and their use from 2007 to 2009 in Mt. Unmum(Cheongdo-gun, Gyeongsangbuk-Do). The vascular plants were summarized as 605 taxa including 98 families, 304 genus, 514 species, 3 subspecies, 68 varieties, and 20 forma. Among the investigated 605 taxa, 21 rare and endangered plants, 29 Korean endemic plants were included. Based on the list of specially designated plants by Ministry of Environment, 70 taxa included Iris odaesanensis and Gastrodia elata were recorded in the investigated area. The naturalized plants were identified as 23 taxa and the percent of naturalized index(NI) was 3.8% of total 605 taxa vascular plants. Usage of 605 taxa were consists of 225 taxa(37.2%) of edible plants, 191 taxa(31.6%) of medicinal plants, 64 taxa(10.6%) of ornamental plants, 46 taxa(7.6%) of pasture plants, 18 taxa(3.0%) of timber plants, 14 taxa(2.3%) of fiber plants, and 3 taxa(0.5%) of industrial plants. To management of natural resource, we suppose that it is required to establish an ecological learning area to minimize human disturbance and an effective managemet strategy by continuous monitoring for ecosystem change.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.817-820
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• 2008

The river environments of many streams in korea have been deteriorate through the rapid industrialization and urbanization since the 1960s. In korea, on the other hand, much efforts on the research and project have been made for the restoration of the deteriorated streams to close-to-nature. in order to restore the deteriorated streams, therefore, it is necessary to investigate such advanced technologies and materials. In view of this requirement, various research paths are being taken focusing on coarse aggregates to make multi-functional porous concrete having continuous voids so as to improve water and air permeability, acoustic absorption, water purification and applicability to vegetation. The Purpose of this study is to investigate the method for recovery of the environment in the streams area using porous concrete retaining wall block. the multi-P.O.C block applies for test in the Jangduri-cheon have been monitored planting, stability etc. after 6 months, plant grows flourishing and reconstructed in state such as nature rivers.

• Korean Journal of Environment and Ecology
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• v.17 no.4
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• pp.337-345
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• 2004

The objective of this study was to monitor vegetation recovery process after timber harvesting at (Mt.) Baekwoonsan Seoul National University Forests, Korea. Two monitoring plots were established in 1994 and woody plant were monitored in 1997, 1999, 2001, and 2003. Vegetation development pattern during last ten years (1994-2003) after timber harvesting were as follows; Styrax obassia, Styrax japonica and Lindera erythrocarpa as of the existing tree were competitive species in the first year after clear-cut, Styrax japonica and Lindera erythrocarpa as of sprout tree and Aralia elata as of seedling were dominant species in the sixth year after clear-cut, and Lindera erythrocarpa, Styrax japonica and Quercus serrata were dominant species from the eighth year to the tenth year after clear-cut. Species diversity index of harvested forest interior was decreased at the southwestern slope while it was increased in the northeastern slope till 6th year and decreased after the 8th year). According to DBH distribution pattern, No. of individuals of Quercus serrata, Styrax japonica and Lindera erythrocarpa showed high frequency in the southwestern slope, and Acer pseudosieboldianum, Styrax obassia, Magnolia sieboldii, Lindera erythrocarpa, and Aralia elata showed good growth in the northeastern slope. There was a difference between slopes in Basal area. It was decreased at the southwestern slopes during the 10th year continuously and it was increased the sixth year however, was decreased after the eighth year at the northeastern slope.

• Korean Journal of Environment and Ecology
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• v.23 no.4
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• pp.333-345
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• 2009

Carpinus laxiflora communities are known as the climax forest community of the temperate zone of Korea. There are three Carpinus laxiflora communities in Seoul. The purpose of this research is to analyze the characteristics of Carpinus laxiflora communities of Seoul and supply basic data for establishing of a management plan. The research sites are Sahmyook University, Mountain Dobong and Jinkwandong. This study considers investigation and the analysis of communities structure, soil characteristics and the growth increment of trees. As the result of study, we could know that the growth increment of the Carpinus laxiflora trees of Seoul is decreasing recently because of soil acidification and so on. Also the vegetation disturbance is increasing because of naturalized plant. Oak wilt disease has appeared in the oak forest around Sahmyook University that is the largest Carpinus laxiflora communities area in Seoul. For that reason the open gap was appeared in forest, and the spread of naturalized plants has been increasing in the gap. Furthermore, the Carpinus laxiflora trees are affected by the Platypus koryoensis which is a kind of oak wilt disease. And so, Unless there is a specific management plan, the survival of Carpinus laxiflora communities are uncertain in Seoul. Therefore the management plan of Carpinus laxiflora communities is necessary such as precise investigation, annual monitoring, etc. For the conservation of the Carpinus laxiflora communities, it is necessary to establish the management plan of the biodiversity for Seoul area.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.865-873
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• 2016

Since 2004, Asiatic Black Bear of the Jirisan National Park is subjected to the restoration project through the re-introduction by the Maritime Province of Siberia in Russia, North Korea, Northeastern part of China and Seoul Grand Park. The purpose of this study is to analyze diets with scat to identify Asiatic Black Bear's feeding habit and eating resources environment in the Jirisan National Park. 78 scats of Asiatic Black Bears were observed during the field studies of radio telemetry-marked bears and by chance in the Jrisan National Park, from 2005 to 2013. The relative frequency of occurrence demonstrated that the plants comprised the highest with 77%, followed by insects with 12.8%, mammals with 5.6%, birds with 0.5%, arthropoda with 0.5%, and others with 3.6%. Also, 52 scats among the collected scats that were measured for the ratio of food were subjected to dry weight, and plants were the highest with 91.2%, followed by mammals with 3.6%, insects with 1.0% and others with 4.2% in the order mentioned. Asiatic Black Bear's feed research demonstrated that the Asiatic Black Bear at Jirisan is omnivorous and that the vegetable food is the main feed instead of animal feed.