• Applied Biological Chemistry
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• v.45 no.2
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• pp.71-76
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• 2002

Several antagonistic bacteria, SD-1, 4, 10, 11, 14, 15, and 16, which have strong CMCase and amylase activities, were isolated from the fermented mushroom media. Among them, SD-1, 10, 11, and 15 have strong antibacterial activities against the mushroom pathogenic bacteria Pseudomonas sp., and SD-1, 10, 11, 14, and 16 have strong antifungal activities against the mushroom pathogenic fungi, Trichoderma sp. SD-14, 15, and 16 did not inhibit the growth of mushroom Pleurotus eryngii ASI-2302, and Pleurotus ostreatus ASI-2042 and ASI-2180. When the culture broth mixture of the seven bacterial strains was applied to the mushroom media, the growths of pathogens, Pseudomonas sp. and Trichoderma sp., were inhibited.

• Economic and Environmental Geology
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• v.43 no.1
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• pp.13-20
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• 2010

Acid mine drainage (AMD) from abandoned mine sites typically has low pH and contains high level of various heavy metals, aggravating ground- and surface water qualities and neighboring environments. This study investigated removal of heavy metals in a biological treatment system, mainly focusing on the removal by adsorption on a substrate material. Bench-scale batch experiments were performed with a mushroom compost to evaluate the adsorption characteristics of heavy metals leached out from a mine tailing sample and the role of SRB in the overall removal process. In addition, adsorption experiments were perform using an artificial AMD sample containing $Cd^{2+}$, $Cu^{2+}$, $Pb^{2+}$ and $Zn^{2+}$ to assess adsorption capacity of the mushroom compost. The results indicated Mn leached out from mine tailing was not subject to microbial stabilization or adsorption onto mushroom compost while microbially mediated stabilization played an important role in the removal of Zn. Fe leaching significantly increased in the presence of microbes as compared to autoclaved samples, and this was attributed to dissolution of Fe minerals in the mine tailing in a response to the depletion of $Fe^{3+}$ by iron reduction bacteria. Measurement of oxidation reduction potential (ORP) and pH indicated the reactive mixture maintained reducing condition and moderate pH during the reaction. The results of the adsorption experiments involving artificial AMD sample indicated adsorption removal efficiency was greater than 90% at pH 6 condition, but it decreased at pH 3 condition.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.270-279
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• 2005

It is important to understand and evaluate the environmental impacts of rice cultivation for developing environmentally-friendly agriculture because rice is main crop in Korea and rice cultivation have both functions of water pollution and purification with environmental and cultivation conditions. This paper presents the evaluation of nitrogen impact by rice cultivation on water system. A simple protocol was proposed to assess the potential amount of nitrogen outflow from paddy field and most of parameters affect on the nitrogen outflow from paddy field such as the amount of fertilizer application, water balance, the quality and quantity of irrigation water, soil properties, nitrogen turnover in the soil and cultivation method were considered. To develop the protocol, coefficients for parameters affected nitrogen turnover and outflow were gotten and summarized by comparison and analysis of all possible references related, and by additional experiments at field and laboratory. And potential amount of nitrogen input and output by water in paddy field were estimated with the protocol at the conditions of the nitrogen contents of irrigation water, amount of fertilizer application, and irrigation methods. Where irrigation water was clean, below 1.0 mg $L^{-1}$ of nitrogen concentration, rice cultivation polluted nearby watershed. At the conditions of 2.0 mg $L^{-1}$ of nitrogen concentration, 110 kg $ha^{-1}$ of nitrogen fertilizer application and flooding irrigation, rice cultivation had water pollution function, but it had water purification function with intermittent irrigation. At the conditions of 3.0 mg $L^{-1}$ of nitrogen concentration and 110 kg $ha^{-1}$ of nitrogen fertilizer application, rice cultivation had water purification function, but that had water pollution function with 120 kg $ha^{-1}$ of nitrogen application. Where irrigation water was polluted over 6.0 mg $L^{-1}$ of nitrogen, it was evaluated that rice cultivation had water purifying effect, even though the amount of nitrogen application was 120 kg $ha^{-1}$.

• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.462-470
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• 2006

The zooplankton community dynamics and grazing experiments was evaluated along a 40 km section of the lower Seomjin river system. Zooplankton was sampled twice a month from January 2005 to June 2006 at three sites (River mouth; RKO, Seomjin bridge: RK12 and Gurae bridge: RK36) in the main river channel. During the study period, the values of most limnological parameters in the three sites were fairly similar, except for conductivity. Annual variation of conductivity in River mouth and Seomjin bridge was more dramatic than which of the other site. There were statistically significant spatial and seasonal differences in zooplankton abundance (ANOVA, P<0.01). Total abundance of major zooplankton groups at both stations was much higher than in Gurae bridge. Among the macrozooplankton, cladocerans abundance was negligible in study sites during study periods. Community filtering rates (CFRs) for phytoplankton and bacteria varied from 0 to 50 mL $L^{-1}\;D^{-1}$ and from 0 to 45 mL $L^{-1}\;D^{-1}$, respectively. The spatial variation of CFRs for phytoplankton was significant (ANOVA, P<0.05). The CFRs of copepods for phytoplankton and bacteria was much higher than that of cladocerans at study sites. Total zooplankton filtering rates on bacteria were slightly lower than filtering rates on phytoplankton. The CFRs of microzooplankton (MICZ) for bacteria were much higher than for macrozooplankton (MACZ) at all sites. Considering the total zooplankton community, MICZ generally were more important than MACZ as grazers of bacteria and phytoplankton in freshwater zone, while MACZ were more important than MICZ as grazers of phytoplankton in brackish zone.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.263-270
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• 2010

This is a research on development of water purification equipment called artificial floating island (=AFI) for the stagnant water area which can secure exuberant landscape and water-friendility. The equipment devised in this study is designed to make up the weakness of conventional AFIs and improves the removal efficiency of pollutants using the mixture of media and plants. The air compressor positioned at the inlet releases air with inflow continuously, the water pump at the outlet sprays as a form of fountain with causing a disturbance on stable water column, then, both of them contribute improvement of water quality over a large area. We applied Bio-stone as a media in this system and performed an experiment of pre-efficiency test, and we concluded that the higher pollutants concentration of inflow, the higher removal efficiency we obtained. At the result of lab-scale experiment, in the case of high-concentration inflow, in the removal efficiency of SS is 62.2%, BOD is 50.2%, COD is 55.1%, T-N is 31.6%, T-P is 38.4%. In addition, to evaluate the field application, we set up the facilities in Sin-gal lake located in Yongin-Si Gyeonggi-Do, and researched on the removal efficiency of outflow relative to the inflow. As a result, SS is 53.5%, BOD is 32.8%, COD is 36.9%, T-N is 22.6%, T-N is 33.2%.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.201-212
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• 2007

This study was conducted to investigate the biology of three species, Tipula latemarginata Alexander, T. nova Walker and T. aino Alexander, of the Genus Tipula in Korea. Field surveys for the biology of the species were carried out at the three sites of Neaseong Stream area in Bongwha County from January 2001 to December 2005. Also many individuals of the species were reared in laboratory to investigate the biology. The larval habitats of the species were streams, rivers, paddy fields, damp earth or leaky revetments. The Tipula larvae were herbivorous. Newly-hatched first instar larvae fed on soft algae, and the larvae gradually fed on leaves, stems and roots of a variety of plants or hard leaf litters, as they grew. During the molting of the larvae their body kept moving from left to right and up and down. Molting usually took not more than 2 hours, and about four hours after molting, the larvae started to eat heavily. The Tipula larvae in aquatic places moved to drier land for pupation and went through short prepupal stage lasting 1-2 days for pupation at fourth instar larval stage. When emerging, the Tipula pupae placed their head and thorax on the earth, but the other parts in the earth. Emergence from the pupal case required about 20 min. to one hour. Mating of Tipula adults took place within 5-7min. after emergence and the duration of mating was about 40 min. The female adults of the species laid eggs by walking with 3 pairs of legs over the damp earth or algal beds. Their body was positioned vertically on the ground with their wings spread $120^{\circ}$ and legs landed on the surface. The oviposition usually took place from one day to 4 days after emergence and the number of eggs carried by female adults were an average of 501-760 per individual. Tipula adults didn't normally feed, and drank water only occasionally. For a few days after emergence, the adults reared in the laboratory rarely drank water. As they neared to death, however, they frequently drank water. The longevity of adults reared in the laboratory with only water during the summer was ca. 4-9 days and males usually survived a little longer than females. The longevity of T. nova was increased 3 times or more as much by feeding them 3% sugar water. Male adults of T. latemarginata outnumbered female adults by 2.6 : 1 in the fields.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.1-8
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• 2009

This study used a mesocosm which presumes movement of the nutrient (especially $PO_{4^-}P$) in the wetland. After setting up the mesocosm inside the wetland and adding the $PO_{4^-}P$, observed the movement of the $PO_{4^-}P$ every hour. We analyzed the variables which had the possibility of affecting $PO_{4^-}P$ concentration in the wetland-flora, absorbing rate of algae, settling rate, release rate. Immediately after adding $PO_{4^-}P$, the concentration of the TP in water column at each mesocosm was 0.48, 12.4, 20.4, $23.6\;mg\;L^{-1}$, after 21 days they were 0.6, 1.92, 6.97 and $6.94\;mg\;L^{-1}$ respectively. The concentration of the TP in water column at the mesocosm decreased on average 73.7%. The concentration of the $PO_{4^-}P$ inside reed, algae and sediment in the mesocosm was increased from $0.73mg\;gDW^{-1}$, $3.81mg\;gDW^{-1}$, $466.1mg\;kg^{-1}$ to $0.83mg\;gDW^{-1}$, $4.57mg\;gDW^{-1}$ and $813.3mg\;kg^{-1}$ respectively. Algae is more sensitive than reeds in absorption of the nutrient. TP removal by settling was highest. Budgeting of TP indicated that P moved from particulates in the water column to sediment and algae. Immediately after adding $PO_{4^-}P$, water column (24.2%) and sediment (49.0%) dominated TP storage, with algae (10.3%) and reed (16.4%) holding smaller proportions of TP. After 21 days, Sediment (59.0%) and algae (17.9%) dominated TP storage, with water column (7.1%) and reed (15.8%) holding smaller proportions of TP. Estimation of phosphate movement using mesocosms is an appropriate method because wetlands have many controlling factors. Analysed data can be compared to background data for wetland construction and management.

• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.210-220
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• 2019

Population growth and the increase of energy consumption due to civilization caused global warming. Temperature on the Earth rose about $0.7^{\circ}C$ for the last 100 years, the rate is accelerated since 2000. Temperature is a factor, which determines physiological action, growth and development, survival, etc. of the plant together with light intensity and precipitation. Therefore, it is expected that global warming would affect broadly geographic distribution of the plant as well as structure and function ecosystem. In order to understand the effect of global warming on the ecosystem, a study about the effect of temperature rise on germination and growth in the plant is required necessarily. This study was carried out to investigate the effects of experimental warming on the germination and growth of two oak species(Quercus mongolica and Q. serrata) in temperature gradient chamber(TGC). This study was conducted in control, medium warming treatment($+1.7^{\circ}C$; Tm), and high warming treatment ($+3.2^{\circ}C$; Th) conditions. The final germination percentage, mean germination time and germination rate of two oak species increased by the warming treatment, and the increase in Q. serrata was higher than that in Q. mongolica. Root collar diameter, seedling height, leaf dry weight, stem dry weight, root dry weight, and total biomass were the highest in Tm treatment. Butthey were not significantly different in the Th treatment. In the Th treatment, Q. serrata had significantly higher H/D ratio, S/R ratio, and low root mass ratio (RMR) compared with control plot. Q. mongolica had lower RMR and higher S/R ratio in the Tm and Th treatments compared with control plot. Therefore, growth of Q. mongolica are expected to be more vulnerable to warming than that of Q. serrata. The main findings of this study, species-specific responses to experimental warming, could be applied to predict ecosystem changes from global warming. From the result of this study, we could deduce that temperature rise would increase germination of Q. serrata and Q. mongolica and consequently contribute to increase establishment rate in the early growth stage of the plants. But we have to consider diverse variables to understand properly the effects that global warming influences germination in natural condition. Treatment of global warming in the medium level increased the growth and the biomass of both Q. serrata and Q. mongolica. But the result of treatment in the high level showed different aspects. In particular, Q. mongolica, which grows in cooler zones of higher elevation on mountains or northward in latitude, responded more sensitively. Synthesized the results mentioned above, continuous global warming would function in stable establishment of both plants unfavorably. Compared the responses of both sample plants on temperature rise, Q. serrata increased germination rate more than Q. mongolica and Q. mongolica responded more sensitively than Q. serrata in biomass allocation with the increase of temperature. It was estimated that these results would due to a difference of microclimate originated from the spatial distribution of both plants.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.1
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• pp.74-80
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• 2022

The vegetation of historical sites has been a form of vegetation that has remained since some years ago, but in modern times, vegetation and terrain have been deformed or damaged due to urban development, which was followed by an industrialization. As a solution to this, it is necessary to establish a plan for restoration and management by referring to the vegetation and landscape remaining in the historic site as indicators. This study was conducted to provide basic data for vegetation and landscape management of Baekje Historic Sites in Seoul by comparing and analyzing location characteristics, existing vegetation, and remaining vegetation of past substitutional vegetation for Pungnaptoseong and Mongchontoseong, Baekje Historic Sites in Seoul. As a result of the study, Pungnaptoseong and Mongchontoseong are located near the main stream of the Han River, Pungnaptoseong is located on a flat land consisting of natural embankments and floodplains, and Mongchontoseong is located on a hilly area. In the case of existing vegetation, it has been confirmed that Pungnaptoseong mainly has ornamental trees planting sites, while Mongchontoseong has a distribution of residual species from the past that grow in villages and hilly lowlands. The Substitutional vegetation of Pungnaptoseong and Mongchontoseong was synthesized based on the location characteristics and actual vegetation, it is estimated that the hilly areas may have been divided into "Quercus aliena Blume.", "Quercus mongolica Fisch. ex Ledeb." and so on, "Pinus densiflora Siebold & Zucc." on dry land,"Salix koreensis Andersson.", "Juglans mandshurica Maxim.", "Alnus japonica (Thunb.) Steud." in rivers and tributaries, "Quercus acutissima Carruth." in the main part of the forest, "Pinus densiflora Siebold & Zucc.", "Salix koreensis Andersson.", "Zelkova serrata (Thunb.) Makino." as a divine tree in the beginning of the village. Since the 1960s, all substitutional vegetation in the past has disappeared due to the introduction of foreign species and the creation of urban areas in Pungnaptoseong and Mongchontoseong, and the landscape has also been damaged. Fortunately, the substitutional vegetation was estimated in consideration of the species of residual trees distributed along the walls, climate, location characteristics, and times, but this study was conducted based on literature and existing vegetation surveys. Therefore, it is necessary to supplement the past target vegetation in Baekje historical sites in Seoul through quantitative experiments such as plant relic analysis in the future.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.272-279
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• 2021

A pump-type eDNA filtering system that can control voltage and hydraulic pressure respectively has been developed, and applied a filter case that can filter out without damaging the filter. The filtering performance of the developed system was evaluated by comparing the eDNA concentration with the conventional vacuum-pressured filtering method at the catchment conduit intake reservoir. The developed system was divided into a voltage control (manual pump system) method and a pressure control (automatic pump system) method, and the pressure was measured during filtering and the pressure change of each system was compared. The voltage control method started with 65 [KPa] at the beginning of the filtering, and as the filtering time elapsed, the amount of filtrate accumulated in the filter increased, so the pressure gradually increased. As a result of controlling the pressure control method to maintain a constant pressure according to the designed algorithm, there was a difference in the width of the hydraulic pressure fluctuation during the filtering process according to the feedback time of the hydraulic pressure sensor, and it was confirmed that the pressure was converged to the target pressure. The filtering performance of the developed system was confirmed by measuring the eDNA concentration and comparing the voltage control method and the hydraulic control method with the control group. The voltage control method obtained similar results to the control group, but the hydraulic control method showed lower results than the control group. It is considered that the low eDNA concentration in the hydraulic control method is due to the large pressure deviation during filtering and maintaining a constant pressure during the filtering process. Therefore, rather than maintaining a constant pressure during filtering, it was confirmed that a voltage control method in which the pressure is gradually increased as the filtrate increases with the lapse of filtering time is suitable for collecting eDNA. As a result of comparing the average concentration of eDNA in lentic zone and lotic zone as a control group, it was found to be 96.2 [ng µL^-1] and 88.4 [ng µL^-1l], respectively. The result of comparing the average concentration of eDNA by the pump method was also high in the lentic zone sample as 90.7 [ng µL^-1] and 74.8 [ng µL^-1] in the lentic zone and the lotic zone, respectively. The high eDNA concentration in the lentic zone is thought to be due to the influence of microorganisms including the remaining eDNA.