• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.707-718
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• 2012

This study was conducted to monitor 4 years of changes in the vegetation structure starting from 2007 when restoration began and propose vegetation management ideas for the riparian ecological restoration areas in the purchased land around Nakdonggang(River). The study was conducted in each of 15 locations ($208,342m^2$) in the riparian ecological restoration areas in November 2007, September 2008, October 2009 and September 2010. The analysis results of the changes in planting species and population showed that, in the case of trees, Acer pseudo-sieboldianum, Quercus acutissima, Acer ginnala, Quercus aliena, Quercus variabilis indicated relatively little changes in their numbers and Quercus dentata, Cornus walteri, Morus alba, Styrax obassia, Sorbus alnifolia var. macrophylla indicated a 100% withering rate. Most shrubs withered due to the oppressive pressure of herbs and climbing plants. The planting density decreased over 4 years on average 28 plants/$100m^2$ to 20 plants/$100m^2$ to 16 plants/$100m^2$. Shortly after the restoration, The the amount of growth was reduced by restoration stress. however as time goes on after the restoration tended to stabilize. The changes in the basal area showed a decrease from $507.1cm^2/100m^2$ in 2007 right after restoration to $301.8cm^2/100m^2$ in 2008 and afterwards showed an increasing trend by going to $324.9cm^2/100m^2$ in 2009 and $372.7cm^2/100m^2$ in 2010. To improve the planting structure of the riparian ecological restoration area, the selection of tree species that have been considered for soil moisture and the differentiation of suitable planting structures that have been considered for local conditions were needed.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.56-71
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• 1980

To study the changes of vegetational composition of each plant successional stage of Pinus densiflora forest caused by pine gall midge damage, Thecodiplosis japonensis, located in Kyonggi-do area, the middle part of Korea, four districts, Anseong, Yongin, Gwangju, and Gapyeong, were selected according to the length of insect damage duration. The forest in the Anseong district was the noninfested one selected as the check. And forests in Yongin, Gwangju, and Gapyeong were the recent]y damaged, severely damaged, and damage prolonged ones in sequence. It was considered that this order could be in concord with the gradual transition of plant successional stage. In view of temperature, precipitation and soil factors, these four districts were sited within the same environment. Four survey plots were selected from each district and the distance between them was 3~4 km. Then again four subplots were set within a plot. Through needle accumulation after insect infestation, light intensity, soil moisture content, and the amount of soil organic matter were increased and these conditions could create a favorable environment enabling the new species invasion and their growth. These were naturally closely related with the increase in quantity of Pinus densiflora defoliation. After considerable time lapse, the quantities of above mentioned factors decreased with the development of the new substitute tree species. It was found that Quercus mongolica was an excellently substitute tree species come first in this studied area. Species diversity increased to a degree at the early stage of the duration of pine gall midge damage and decreased thereafter. As the same manner, similarity index value between plots in the same district decreased to a degree and increased thereafter. This was linked admittedly with the increase and decrease of tree species and evenness. Synthesizing above mentioned results, the process of plant succession studied quantitatively by changes of relative density and relative importance value, it can be concluded that Pinus densiflora forest gives way to Genus Quercus forest in which Genus Lespedeza and Genus Rhododendron species become as subdominance species after removal of the Pinus densiflora trees damaged by pine gall midge.

• Korean Journal of Ecology and Environment
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• v.44 no.3
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• pp.253-263
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• 2011

This study was conducted to gain preliminary data for restoration and management of constructed small-scale ponds in paddy fields through analysis of their physicochemical and biological properties. A field survey was performed at 13 small-scale ponds located in paddy fields from August 2009 to October 2010. Structural properties, water quality, soil characteristics and fish fauna were measured. Results showed that small-scale ponds without frames might lose their function over time because of crumbling walls. Therefore, it is necessary for these ponds to have frames for soil protection and sustainable maintenance. Chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) concentration were higher than the water quality standard for agricultural water in small-scale ponds. In particular, TN concentration was 8.03 mg $L^{-1}$ and over 8 times the water quality standard because of the presence of livestock such as cows and pigs in the study areas. Sand, organic matter and available phosphorus contents of soil in small-scale ponds was 53.4${\pm}$16.6%, 21.8${\pm}$9.74 g $kg^{-1}$ and 12.8${\pm}$7.59 mg $kg^{-1}$, respectively indicating that sand and available phosphorus contents were suitable for plants in small-scale ponds, but organic matter contents was somewhat low in newly constructed small-scale ponds, and would take some time to stabilize for plant growing. Fish fauna was not diverse with only 4 species at all sites surveyed. Collected fishes share a common feature that they all inhabit paddy fields or canals with shallow water depth. In this study, all ponds were not linked to the streams and canals around them. It appears that connection to adjacent streams was the major factor controlling fish fauna in small-scale ponds. The results of statistical analysis were classified into three groups. Factor 1 was 26.3%, which shows a structural properties such as area and depth of small-scale pond. As for factor 2, it appears on 20.1%, showing water quality like a TP, suspended solids (SS) and COD. Small-scale ponds were classified into three groups by factor scores. Group I consisted of 6 small-scale ponds, which were larger than the others. Group III had higher water quality than the others. We conclude that the most important points to be considered for restoration and management of small-scale ponds is connection with adjacent streams or ditches and depth and size of the small-scale pond.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.145-156
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• 1996

The effects of priming with different polyethylene glycol (PEG 6, 000) solutions on the germination, emergence characteristics and early plant growth in rice, barley and wheat were investigated. Rice, barley and wheat seeds were subjected to various priming conditions of osmotic potentials (-0. 75, -1.00 and -1.50 MPa) of PEG, and incubation period were 5 days at 25, 20, 2$0^{\circ}C$, respectively. The percentage of water absorption was highest in barely, and lowest in rice, and all the treatments enhanced water absorption in barley, but showed no significant effects in rice and wheat. Respiration quotient was lower than none PEG treatment seeds, and those of barley and wheat were higher than rice regardless of PEG concentration, and that of rice increased with high PEG concentration. Total germination percentage of osmoconditioning seeds with PEG was higher than that of none treatment seed, and those of barley and wheat were significant. The artificially deteriorated seeds with PEG treatment seeds after ageing treatment could recover to nearly the same germination level as that of the control seeds. The effects of coating polymer were higher than osmoconditioning with PEG, and germination characteristics in rice showed varietal difference at PVP and waterlock at recoated seeds after PEG treatment. Osmoconditioning with PEG reduced mean germination and emergence time, but there was no difference among PEG concentrations. The plant height of PEG treaed seed in rice was taller and those of barely and wheat showed varietal difference, and those of polymer-coated seed after PEG treatment were different among the polymers. The dry weight of PEG treatment were different among the crops, and those were increased with the high PEG concentration. The emergence percentage of PEG-treated seed were higher than none-treated seed, and those were decreased with the increased PEG concentration, and the highest emergence percentage of rice, barley and wheat were 90, 50 and 50% soil moisture content, respectively. The time to emergence in rice was longer than barley and wheat, and those in rice was shortened in high soil moisture content, and barley and wheat were shortened in low soil moisture content.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.50-58
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• 1995

These studies were carried out to develop a system for non -destructive and continuous measurement of fresh weight and to analyse the growth response of leaf lettuce under the different nutrient solution and light condition with this system. The developed measurement system was consisted of four load cells and a microcomputer. The output from the system was highly positive correlation with the plant fresh weight above the surface of the hydroponic solution. The top fresh weight of plant could be measured within the error $\pm$ 1.0g in the range of 0 - 2000g. The top fresh weight of leaf lettuce increased 44 times at 18th day after transferring to the nutrient solution, and the maximum growth rate was observed at 13th day after transferring. The growth rate was 10.7- 29.6% per day during 18 days. Optimum concentration of the nutrient solution for the growth of lettuce was 1.4 - 2.2 mS/cm of EC level. When the light condition was changed from dark to light, the fresh weight was temporarily decreased, but the fresh weight increased under the opposite condition. Top fresh weight of leaf lettuce in the darkness normally increased within 12 hours after darkness treatment, and then slowly increased until 78 hours under continuous dark condition. After that times, the fresh weight began to decrease.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.208-217
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• 2020

A biopolymer based on microorganism-derived β-glucan and xanthan gum is being studied as a new eco-friendly material that stabilizes the riverbank slope, and also promotes vegetation growth. However, it is still inconclusive whether biopolymers have a positive effect on plant performance in the riverbanks which are subjected to various climatic factors and plant competitions. For a practical ecological evaluation of the biopolymers, their effect on plant growth promotion was studied in a natural environment. Considering the relationship between competition and plant community formation, the effects of biopolymers on competition were also investigated. For four plant species (Echinochloa crus-galli, Pennisetum alopecuroides, Leonurus japonicus, and Coreopsis lanceolata), the biopolymer effects under intra/interspecific competition were tested at the riverbank (20 m × 10 m) near Samjigyo Bridge in Damyang-gun, Jeollanam-do. A biopolymer powder was mixed with water and commercial soil following the manufacturer's recommendations. The soil mixed with the biopolymer was filled in a pot or applied to the surface of the commercial soil with a thickness of 3 cm. Across the competition treatments, the biopolymer treatment promoted root growth of the target plant species and decreased the specific leaf area. The total biomass and shoot dry weight of P. alopecuroides increased in response to the biopolymer treatment. The competition treatment decreased the total biomass and shoot dry weight compared to the case without competition. Notably, such a competitive effect was similar in all the biopolymer treatments. Thus, biopolymers, when mixed with soil, promote the growth of some plant species, but do not appear to affect the competitive ability of plants.

• Conservation Science in Museum
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• v.30
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• pp.23-46
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• 2023

The Jija Chongtong Gun, owned by Seokdang Museum of Dong-A University, is a tubedstyle heavy weapon of the battlefield in the mid-Joseon Dynasty and is the second largest firearm after Cheonja Chongtong. The original surface color of the Jija Chongtong Gun was obscured by foreign substances and therefore it was judged that its condition requires the conservation treatment. For stable conservation treatment, gamma ray and X-ray non-destructive transmission surveys was conducted to determine the internal structure and conservation condition. And the component analysis on the material components and surface contaminants of Jija Chongtong Gun was conducted by utilizing the p-XRF component analysis, SEM-EDS component analysis, and XRD analysis. As a result of the gamma-ray and X-ray non-destructive transmission investigation, a large amount of air bubbles was observed inside Jija Chongtong Gun, and the part that appeared to be a chaplet by visual observation was not identified. As a result of gamma-ray and p-XRF component analysis, it was confirmed that Jija Chongtong Gun was bronze made of copper (Cu), tin (Sn), and lead (Pb) alloy. As a result of surface analysis of foreign substances using SEM-EDS, it was confirmed that the main components of white foreign substances were calcium (Ca), sulfur (S), and titanium (Ti). Titanium was presumed to be titanium dioxide (TiO₂), the main component of white correction fluid. The red foreign substance was confirmed to contain barium (Ba) as its main ingredient, and was presumed to be barium sulfate (BaSO₄), an extender pigment in paint. White and red contaminants, mainly composed of titanium and barium, are presumed to have been deposited on the surface in recent years. The yellow foreign substances were confirmed to be aluminum (Al) and silicon (Si), and were presumed to have originated from soil components. As a result of SEM-EDS and XRD component analysis, the white foreign substance was confirmed to be gypsum (CaS). Based on the results of component analysis, surface impurities were removed, stabilization treatment, and strengthening treatment were performed. During the conservation process, unknown inscriptions Woo (右), Byeong (兵), Sang (上), and Yi (二) were discovered through a portable microscope and precise 3D scanning. In addition, the carving method, depth, and width of the inscription were measured. Woo Byeong Sang is located above Happo Fortress in Changwon, and Yi can be identified as the second hill.