• The Korean Journal of Ecology
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• v.17 no.3
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• pp.355-366
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• 1994

The purpose of this study was to investigate the changes of water quality and the patterns of self-purification with season in Gokneung stream. The vegetation in the ecosystem around Gokneung stream was dominated by Quercus species. In the physicochemical analysis based on the contents of DO, BOD, conductivity and total phosphorus, the upstream seemed to have been polluted, but the downstream was self-purified. In biological investigation by bentic macroinvertebrates, the result was similar to that in the physicochemical analysis. The self-purification constant based on BOD of the upstream, 1.013, was the highest. In the self-purification constants with month, that of September was 0.995 and that of January was 0.272. These results indicated that the self purification capacities of spring and autumn were larger than those of winter and summer in Gokneung stream.

• The Korean Journal of Ecology
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• v.4 no.3_4
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• pp.93-108
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• 1981

This investigation includes the sick soil phenomenon caused by the self-poisoning of Setaria italica, Sorghum nervosum, Zea mays and Miscanthus sinensis among Poaceae. It elucidates whether the poison is directly excreted from the root or the secondary product resulting from the decomposition in the soil; the effect of Miscantus sinensis on the germination and growth of other plants, and the effect of Zea mays grown between furrows to shade Angelica gigas on its growth. The results obtained are as follows; Supplied with the leakage water from the pots, in which the same plants as the test ones were grown, in anticipation of the poison to be directly excreted from their roots, Sataria itlaica and Zea mays exhibited the growth inhibition more than 30%, whereas Sorghum nervosum and Miscanthus sisnensis were not effected in growth at all. When cultivated in the soils mixed with the roots of the some plants as the test ones, in anticipation of the poison to be the secondary product resulting from the decomposition in soil, Setaria italica and Zea mays showd growth inhibition of more than 50%, which is greater than that of the case of the leakage water, and Miscanthus sinensis exhibited no inhibition either, whereas Sorghum nervosum in the 50% plot showed heavy growth inhibition of more than 80% to the case of the leakage water. The common or uncommon plants found easily in the group of Misscanthus scinenis were not affected by the extracts of the steam and leaves of Miscanthus sinensis in germination and growth. Supplied with the leakage water from the pots in which Miscanthus sinensis was grown, among Lespedeza crytobotrya, Oenothera odorata, Raphanus sativus val'. acarlthiformis, Zoysia japonica, Patrinia scabiosaefolia. which are easily found in the group of Miscanthus sinensis, only Patrinia scabiosaefolia was slightly inhibited in growth in the 100% plot, whereas the others did not show any inhibition at all. Mean while, Amaranthus patulus. Solanum nigrum, Capsella bursa-pastoris val'. triangularis, Alopecurus amurensis, Chenopodium album val'. centrorubrum, which could not be found in the group of Miscanthus sinensis, were all distinctly inhibited. In the experiment on the effect of Zea mays on the growth of Angelica gigas, its growth was severely inhibited by one-half to two thirds with the increased concentration in both the cases of growing in the mixture of the soil and the powdered root of Zea mays and being supplied with the leakage water from the pot in which Zea mays was grown.

• Journal of Society of Preventive Korean Medicine
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• v.5 no.2
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• pp.8-28
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• 2001

This investigation grasps the level and relevant elements of performance of health promotional activities for the elderly in Korea. It provides fundamental data on health promoting projects targeting the elderly population from farming villages. Hence, this study gropes for an effective approach and measures of health promoting programs. The program needs to be developed with a focus on elderly people from farming villages. In addition, it was carried out in order to provide basic data for development of health projects for local communities. Data gathering was based on survey data targeting patients from the free clinic service. Service was rendered for the residents of farming villages, and conducted at the Offices of CheonBuk Province from October 2000 to December 2000. Analytical results were used to examine the health promotional method for the elderly in the aspect of Oriental Medicine. SPSS 9.0 version as well as T-test and ANOVA were used for survey data analysis. Piersons correlation coefficient was utilized for the relationship for each area, obtaining the following analytical results. 1. The average score for the activities of health promotion was 2.28. Looking at each subcategory, stress management was the highest at 3.65; interpersonal relationship, 3.00; nutrition, 2.55; health responsibility, 2.15; self-realization, 2.03; and exercise was the lowest at 1.89. 2. With respect to lifestyle of the health promotion secondary to general features of elderly people from farming villages, the level of activities of health promoting lifestyle was shown to be higher for males than that of females. Self-realization area was high among males in detailed particulars while the level of execution was high as age decreases in the stress area. 3. Regarding health promoting life style secondary to socioeconomic characteristics, the level of execution was higher for the individuals with a higher level of education and further utilization of spare time. With respect to occupation, the level was highest for people from the fishery. The level decreased in the order of other occupations such as trade, unemployed and agriculture, which was shown to be the lowest. In detailed particulars, it revealed that higher the individuals educational level, the higher the self-realization and stress management areas. The level of interpersonal relationship was the highest among people with little or no education. With respect to self-realization area, the level was highest among the cases where one paid living expenses along with their children. The lowest level of living expenses was seen in the cases where an individual pays for living expenses by himself/herself. There were significant results in all areas except for nutrition areas depending on occupation. The fishery was shown to be the highest. The level of activities was higher as one utilizes more spare time in all areas except for the area of interpersonal relationship.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.8
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• pp.895-903
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• 2007

As for the increasing demanding on the development of direct-ecological landfill monitoring methods, it is needed for critically defining the condition of landfills and their influence on the environment, quantifying the amount of enzymes and bacteria mainly concerned with biochemical reaction in the landfills. This study was thus conducted to understand the fates of contaminants in association with groundwater quality parameters. For the study, groundwater was seasonally sampled from four closed unsanitary landfills(i.e. Cheonan(C), Wonju(W), Nonsan(N), Pyeongtaek(P) sites) in which microbial diversity was simultaneously obtained by 16S rDNA methods. Subsequently, a number of primer sets were prepared for quantifying the specific gene of representative bacteria and the gene of encoding enzymes dominantly found in the landfills. The relationship between water quality parameters and gene quantification were compared based on correlation factors. Correlation between DSR(Sulfate reduction bacteria) gene and BOD(Biochemical Oxygen Demand) was greater than 0.8 while NSR(Nitrification bacteria-Nitrospira sp.) gene and nitrate were related more than 0.9. A stabilization indicator(BOD/COD) and MTOT(Methane Oxidation bacteria), MCR(Methyl coenzyme M reductase), Dde(Dechloromonas denitrificans) genes were correlated over 0.8, but ferric iron and Fli(Ferribacterium limineticm) gene were at the lowest of 0.7. For MTOT, it was at the highest related at 100% over BOD/COD. In addition, anaerobic genes(i.e., nirS-Nitrite reductase, MCR. Dde, DSR) and DO were also related more than 0.8, which showing anaerobic reactions generally dependant upon DO. As demonstrated in the study, molecular biological investigation and water quality parameters are highly co-linked, so that quantitative real-time PCR could be cooperatively used for assessing landfill stabilization in association with the conventional monitoring parameters.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.129-150
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• 1985

The present investigation was conducted to provide a systematic approach necessary to establish an integrated insect pest management program of barley in Korea. Some ecological surveys on insect pests of barley have been undertaken at the field of Experimental Station, Ky$\check{o}$ngbuk Provincial Office of Rural Development as a fixed point survey area, and at 23 localities for round survey throughout southern and central Korea from 1983 to 1984. Previously known insects injurious to barley in Korea were revised and the population dynamics of 10 dominant harmful species were analyzed according to either 24 localities or 25 cultivars respectively by using several sampling methods of net sweeping, black light traps, yellow water pan traps and visual counting. As the results, a total of 94 species belonging to 77 genera under 32 families are known to be injurious to barley, among them 20 species are newly added here. In the population density level, the dominant species were disclosed as Laodelphax striatellus (43.1 %), Macrosiphum avenae(27.0 %), Rhopalosiphum padi(6.5 %), R. maidis(5.4 %), Psammolettix strialus(2.7 %), Chlorops oryzae(2.2 %), Agromyza albipennis(2.1 %) Phyllotreta nemorum(1.4 %), Chaetoenema cylindrica(1.0 %), Dolycoris baccarum(1.0 %) in order. For the general abundance of major insect pests, it was highest in the cultivar P'aldal whereas lowest in Milyang #22. There were tendencies that Psammotettix striatus, Dolycoris baccarum, Phyllotreta nemorum and Chaetocnema cylindrica represented a maximum increase in the beginning of June, while Chlorops oryzae and Agromyza albipennis showed in the middle of May but aphids were in the end of May. In the dominance of natural enemies, Nabis stenoferus occupied 21.4 % and Propylaea japonica 9.6 %.

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.8-15
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• 1992

Arrowhead (Sagittaria trifolia L.), a perennial weed dominant in paddy field, is considerably difficult to control by herbicides. The investigation on the effects of environmental factors on emergence of arrowhead tuber can aid for controlling this weed. The results exmined were as follows : From the results of emergence characteristics at different levels of temperature, arrowhead tuber could germinated at 15$^{\circ}C$-40$^{\circ}C$. The optimal temperature for basal emergence was ranged from 25 to 30$^{\circ}C$. Basal emergence at 15$^{\circ}C$ and 20$^{\circ}C$ began at 56 and 12 days after tuber plantation, respectively and were later than those at the optimal temperature. At the different levels of shading, all the tested tubers could emerged. The days required for basal emergence at 25% and 50% shading plots were shorter than those at 70%, 80% and non-shading plots. The basal emergence was more effective under blue and clear films than any other phyto-selective materials. Some of arrowhead tubers could not emerged under green, red and yellow films. On the soil pH, the basal emergence was best at soil pH 6.0 and 7.0. At soil pH 4.0, 5.0 and 8.0, the required days for emergence were longer than those at soil pH 6.0 and 7.0 and some of tubers could not emerged. Arrowhead tubers more then 0.5 g showed the shorter shooting days than those less than 0.5 g. Tubers were able to emerge at water depth ranging from 0 to 20 cm. At 3 cm and 5 cm water depth, the required days for basal shooting were shorter than those at any other levels of water depth. The emergence of basals was best at molding depth of 0 cm, and the rates at 3 to 5 cm of plantation depth were decreased. At 10 cm plantation depth, the shooting rate was significantly decreased.

• Journal of Wetlands Research
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• v.18 no.1
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• pp.32-38
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• 2016

The purpose of this study is to investigate the effects of the natural river conservation work and to find remedies for them, targeting Jangsu-cheon with high frequency of use by citizens among the rivers in Incheon Metroplitan City, Korea; for this, this study conducted investigations and analyses of Jangsu-cheon completed in December, 2008. As a result of investigating 3 spots for the water system of Jangsu-cheon over a total of 3 years (2009, 2010, 2014), it was found that benthic macro-invertebrates of a total of 3 phyla, 5 classes, 11 orders, 26 families, 56 species, and 980 specimens were distributed there. When they were analyzed by year, 18 families and 30 species in 2009, right after the natural river conservation work, and 22 families and 37 species in 2010, 2 years after the work, were found, with 7 species increasing in number; after that, as a result of the investigation in 2014, 22 families and 38 species were found, which tells the river has entered the stabilization stage since the recovery in 2010.Therefore, this study could identify: the water environment of the river was improved due to the natural river conservation work for Jangsu-cheon; in addition, Jangsu-cheon showed good ecological environment due to the continuous maintenance of the good wetlands in Incheon Grand Park in the upper area of the river; and the natural river conservation work of Jangsu-cheon created positive effects.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.235-248
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• 2010

This study was carried out to the actual conditions and improvement of the eco-forests master plan in South Korea, and suggested its problems and improvement direction. Results from survey and analysis of limiting factors or constraints in the construction plans of eco-forests in Korea revealed that there were highly frequent problems involving site feasibility, topographic aspect, and existing vegetation. The results of survey on the status of land use indicated that the average ratio of the use of private estate was 29.7%, so then it was estimated that a great amount of investment in purchase of eco-forest site would be required. Results from survey on major introduced facilities showed that there was high frequency of introduction of infrastructure, building facility, recreational facility, convenience facility, and information facility, and that there was low frequency of introduction of plant culture system, ecological facility, structural symbol and sculpture, and the likes. There was just one eco-forest park where more than 500 species of plants grew, and the result of investigation indicated that the diversity of plant species in 11 eco-forest parks was lower than the standards for construction of eco-forest. Results from analysis of the projects costs revealed that investment cost in facilities was higher than planting costs, and that a large amount of investment was made in the initial stage of the project. There was no planned budget for the purpose of cultivating and maintaining the plants and vegetation after construction of eco-forest. The basic concepts in construction of eco-forests were established according to the guidelines presented by the Korea Forest Service; however, the detailed work of the project was planned with its user-oriented approach. Then the construction of eco-forest was being planned following the directions, which would lead to development of a plant garden similar to arboretum or botanical garden. Therefore, it is required that the architect who designs eco-forest as well as the public officer concerned firmly establish the concepts of eco-forest, and that, through close analysis of development conditions, a candidate site to fit the purpose of constructing eco-forest be selected, and also a substantive management plan be established upon completion of construction of eco-forest.

• Korean Journal of Ecology and Environment
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• v.37 no.4 s.109
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• pp.436-447
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• 2004

Wetland plants have evolved specialized adaptations to survive in the low-oxygen conditions associated with prolonged flooding. The development of internal gas space by means of aerenchyma is crucial for wetland plants to transport $O_2$ from the atmosphere into the roots and rhizome. The formation of tissue with high porosity depends on the species and environmental condition, which can control the depth of root penetration and the duration of root tolerance in the flooded sediments. The oxygen in the internal gas space of plants can be delivered from the atmosphere to the root and rhizome by both passive molecular diffusion and convective throughflow. The release of $O_2$ from the roots supplies oxygen demand for root respiration, microbial respiration, and chemical oxidation processes and stimulates aerobic decomposition of organic matter. Another essential mechanism of wetland plants is downward water movement across the root zone induced by water uptake. Natural and constructed wetlands sediments have low hydraulic conductivity due to the relatively fine particle sizes in the litter layer and, therefore, negligible water movement. Under such condition, the water uptake by wetland plants creates a water potential difference in the rhizosphere which acts as a driving force to draw water and dissolved solutes into the sediments. A large number of anatomical, morphological and physiological studies have been conducted to investigate the specialized adaptations of wetland plants that enable them to tolerate water saturated environment and to support their biochemical activities. Despite this, there is little knowledge regarding how the combined effects of wetland plants influence the biogeochemistry of wetland sediments. A further investigation of how the Presence of plants and their growth cycle affects the biogeochemistry of sediments will be of particular importance to understand the role of wetland in the ecological environment.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.551-560
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• 2013

Environmental factors and epilithic diatom communities in the lower streams near the harbor region of South Korean peninsula were examined during no monsoon period in May 2013. The sampling of water and epilithic diatoms was conducted at both streams, 19 regulated streams (RS) that there are one or several dams constructed in the river system, and 19 un-regulated streams (US) that there are no dams within the river. A cluster analysis based on the number of species and abundance of epilithic diatoms through the stations, divided into three groups such as groups I (mainly US), II (mixed with US and RS) and III (mainly RS), respectively. Group I showed that water quality is good and high diversity of diatom, while Group II and III was water quality is relatively poor, but not differed in biomass of diatom from Group I. In addition, Group II that had high conductivity, nitrogen and phosphorus, was the lowest in diatom diversity among them. Dominant species were Nitzschia palea (17%) and Navicula seminuloides (11%) in Group I, Nitzschia inconspicua (19%) and Navicula perminuta (9%) in Group II, and Nitzschia inconspicua (15%) and Nitzschia palea (14%) in Group III, respectively. These taxa were widely distributed in brackish water, and not closely related with specific water quality, like eutrophic water. However, the groups II and III belonged to RS, had not only little biomass, but bad water quality such as high concentrations of nutrient and chlorophyll-a. Therefore, to determine the effect of dam construction on the lower water ecosystem, the planktonic algae, which can occur algal bloom in the estuary, also was considered to be a parallel investigation.