• Korean Journal of Environment and Ecology
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• v.27 no.1
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• pp.71-84
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• 2013

This study investigated some of the specific ecological characteristics Torreya nucifera forest and its health conditions so that was drawn from four different management strategies, such as Types A, B, C, and D, for protected areas of forest genetic resources. Type A refers to passive management which routinely keeps the current status of forests by removing competitive trees or curing damaged ones. Type B, as active one which improves Torreya nucifera forest, includes increase of soil pH and removal of Sasa borealis, Phyllostachys bambusoides, and deciduous broad-leaved trees such as Quercus variabilis, Carpinus tschonoskii et al.. Type C is another passive one which reduces soil acidity within Chamae cyparisobtusa forest and maintains the existing forests. Type D is another active one which decreases soil acidity and simultaneously reduces problems associated with competitive and invasive plants to nurture the young trees. At last, it is important to note that the protected areas for forest genetic resources need to be entitled to categories III(natural monument) or IV(habitat/species management area) in accordance with protected area management guidelines of IUCN.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.888-895
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• 2016

The population ecology (Ecological characteristics) of Squalidus chankaensis tsuchigae were investigated at Geum River from March to November, 2013. This species inhabited midstream of the river where was mostly covered with cobble and sand. The depth of the habitat was 30~60 cm and velocity of stream was 2.27~4.88 cm/sec. The sex ratio of female to male was 1 : 0.86. They were sexually mature when they were over two years of age. The spawning period was from June to July with water temperatures from $25^{\circ}C$ to $25^{\circ}C$. Sexually matured individuals appeared over the two year of age. Frequency analysis of total length indicated that the group with 55~70 mm in total length was one year old, the 71~90 mm was two years old, and the group over 91 mm was three years old. The average number of eggs in the ovaries was estimated as 2,219 per matured female. The number of matured eggs size in ovaries was 0.64~0.98 (mean: 0.85) mm. Calulation length-weight relation of S. chankaensis tsuchigae show the value of contant a as 0.0002 and b as 2.81, and condition factor (K) was 1.06 on average. The stomach contents were Cyanophyta, Chlorophyta, Bacillariophyta, Crustaceae, Copepoda, Nematota, Actithocephala, and Ephemeroptera, Hemiptera, Diptera, and Trichoptera that belong to Aquatic insect, and dormant bud of Pectinatella that belongs to Phylactolaemata. The diet of S. chankaensis tsuchigae was omnivorous, mainly vegetable feed on attached algae (filament form), and mainly animality feeded on benthic invertebrates such as Chironomidae larvae.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.829-836
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• 2016

This study was carried out on Kongju National University and its neighboring area, Mt. Gyeryong national park and Mt. Worak national park in the breeding season of long-tailed tits Aegithalos caudaatus from 2008 to 2012. The result of the inquiry, the nests were found in 15 species of trees, and this result shows me it's not choosy about them. But after having classified them according to the features and analyzed them, long-tailed tits preferred evergreen needleleaf tree and deciduous broad-leaf tree and deciduous bush, especially evergreen needleleaf tree. The concealment rate of long-tailed tits' nests was $11.61{\pm}4.79%]\;4.38{\pm}2.19%$(n=29) in Kongju National University and it's neighboring area, $6.06{\pm}2.31%$(n=43) in Mt. Gyeryong national park and $4.38{\pm}2.19%$(n=32) in Mt. Worak national park. By regional groups, the concealment rates of neighboring nests were almost same, but there are no differences among the areas. The average of the color codes was $26.52{\pm}16.14$(n=32) that those of the nest subtract from those of surroundings of the nest. The nests were procryptic according to their surroundings, and if their nest in a tree were evergreen needleleaf trees, they were made of moss. while if the trees of nest in a tree were yellow because of fungus, made of dried moss, they were yellow, too.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.857-864
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• 2016

To analyze the behavioral characteristics of Korea endangered species female gorals (n=6) during the period of birth, using GPS collar attached on their necks, we carried out this study in two areas (Seoraksan and Woraksan National park) from March 2007 to May 2014. According to our analysis there was a change in their home range during the period of birth. The home range of females (n=6) in MCP 95% was Spring ($1.00{\pm}1.00km^2$) > Autumn ($0.66{\pm}0.30km^2$) > Summer ($0.61{\pm}0.40km^2$) > Winter ($0.50{\pm}0.10km^2$) (F=4.198, p<0.05). In the monthly analysis, their home ranges were dramatically reduced in May, June and July. It showed a statistically significant difference (F=24.261, p<0.01). These gorals showing a drastic change in home ranges were identified as gorals having offspring individual and their home ranges were decreased. The average altitude was $615.77{\pm}173.508m$ and there was no significant difference in major change between parous and nonparous female gorals. Through this analysis, we expect that it can be applied to the goral management and restoration project considering the time of birth.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.489-494
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• 2006

For the ecosystem conservation and the effective management of naturalized plant species on 261 uninhabited islands distributed in southern and western sea in Korea, we tested the interrelationship between the pattern of distribution and dispersal of the naturalized plant species and the factors of geographical environment of uninhabited islands such as island area, distance from mainland, latitude, longitude, human impacts and habitat diversity. Out of 261 uninhabited islands surveyed, 106 species of the naturalized plants occurred on 229 (87.7%) islands. The naturalized plant species per island averaged 4.6 (SD=4.07) species, and plant species number were higher in southern group (87 species) than in western group (64 species) of islands. Plant species occurred on more than 100 islands were three species : Rumex crispus L. (153 islands), Erigeron annuus Pers. (130 islands), and Conyza canadensis (L.) Cronquist (121 islands), the highest grade '5' of 'degree of naturalization'. The occurrence frequency of 106 naturalized plant species was significantly correlated with island area, distance to mainland, strength of human impacts, and latitude and longitude. Correlation coefficient (r=-0.330) between occurrence frequency and distance from mainland was higher than between occurrence frequency and island area (r=-0.182). The result of path analysis confirmed that plant species number was significantly affected by island area p=0.336) and distance from mainland (p=-0.490), but in this analysis the effect of human impacts on plant species number was very weak (p=0.003). On the basis of these results, strategies on the conservation of ecosystem and the management of naturalized plant species in the uninhabited islands of Korea were discussed.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.531-537
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• 2006

We assessed the species composition and structure of the three representative forest stands(Pinus densiflora stand, Quercus variabilis stand, and Ouercus mongolica stand), dominated in the National Long-Term Ecological Research Sites of Mt. Worak, Korea and established a benchmark series of permanent plots and transects with which future changes in forest composition and structure could be monitored. Species richness of Q. mongolica stand was greater than other two stands, due in large part to the greater habitat heterogeneity. Number of trees and species are decreased with increasing DBH classes. The successional trends of the three study stands would be mostly changed as Q. mongolica forest, regardless of forest types. Mean density ratio between alive trees and dead trees of three forest stands appeared with Q. mongolica stand 75:25, Q. variabilis stand 94:6, and P. densiflora stand 86:14, Q. mongolica stand appeared most highly from in three stands. This may be due to interspecific or intraspecific competition that it follows in various successesional stages. One side, when it saw the tree status which shows the tree health, the three forest stands all standing alive type (AS) appeared most highly with 75% to 85% and fallen dead type (DF) did not appear entirely. Remeasurement of permanent plots at periodic intervals will provide useful information on the dynamics of the forest vegetation that can be used in the development of adaptive conservation plans.

• Journal of Korea Water Resources Association
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• v.44 no.1
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• pp.23-30
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• 2011

Any significant inflow of fresh water due to flood or snow melting can rapidly reduce salinity at the bay. In such a case, the habitat environment in the sea near river mouth can be partly destroyed. Therefore, research to understand the salinity distribution quantitatively at the bay for the utilization of natural environment and for the inhabitant conservation must be very important. In this study, the investigation on the relationship between satellite image and turbidity is carried out first, and then the salinity distribution at the bay using the relationship between turbidity and salinity is derived. The main results are as follows. First the reappearance ability of RGB bands respectively of the satellite image is investigated, and then it was confirmed that the combination of band2 and band3 expressed best the movement characteristics of turbid water at the bay is chopped up into 4 small areas. Second the turbidity of river mouth is estimated using the travel time from the upward monitoring station to the river mouth. Finally the satellite image is converted into the salinity distribution by the correlation of salinity and turbidity. It is confirmed that the salinity distributions obtained from above three investigation methods are quite reasonable and clear.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.334-342
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• 2016

In this study, we explain the environmental variables that mainly influence the spatial and seasonal pattern of Galerucella nipponensis in 38 wetland and stream located at mid-low Nakdong River. G. nipponensis were found at total of 32 wetland, was strongly positively correlated with the biomass of Trapa japonica (t=2.173, $r^2=0.013$, p<0.05). In result of seasonal distribution during 3 years, the largest density of G. nipponensis adult were observed in summer (7~8 months), egg and larva was recorded in only early spring (4~5 months). Rainfall were negatively related with the seasonal distribution of G. nipponensis. They were more abundant in dry season (2015 year) than rainy seasons(2013~2014 year). Stable isotope analysis showed that the G. nipponensis consumed as food source no submerged leaf of T. japonica than other plant. However, utilization of T. japonica on Galerucella nipponensis were not influence to plant biomass and/or species composition in vegetated bed. Those considered as adaptive strategies for sustainable habitat maintenance that because T. japonica use as not only food source but also their lives for G. nipponensis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.1-7
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• 2020

As of 2018, Steel slag was generated approximately 24.23 million tons. Howeve, except blast furnace slag, steel slag is a typical by-product which does not have a clearly defined purpose in recycling. Thus, countries around the world are putting great efforts into developing a purpose for the recycling of steel slag. The vast habitat foundation of marine life has been destroyed due to recent reckless marine development and environment pollution, resulting in intensification of the decline of marine resources, and a solution to this issue is imperative. In order to propose a method to recycle large amounts of by-product slag into a material that can serve as an alternative to natural aggregate, the engineering properties and applicability for each mixing factor of environment friendly porous concrete as a material for the composition of seawater purification were in this study. Regarding the nutrient elution properties, it was clear that the nutrients continuously flowed out up to an immersion time by 8 months in natural seawater; the nitrogenous fertilizer displayed excellent elution properties in this regard.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.552-564
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• 2019

The purpose of this study was to investigate vegetation characteristics of evergreen broad-leaved forests in the area of Duryunsan Provincial Park, where the deciduous broad-leaved trees and evergreen broad-leaved trees are mixed and thus had a high botanical value. To investigate the vegetation characteristics, we installed 40 quadrats with an area of $100m^2$ each for survey and analysis. Haenam-gun, where the Duryunsan Provincial Park is located, is a warm-temperate forest region. The meteorological data for the past 40 years showed a coldness index of $-8^{\circ}C$, a monthly warmth index of $109.2^{\circ}C$, and annual mean precipitation of 1,310.5mm, indicating it is an ideal habitat for the distribution of evergreen broad-leaved forest. The results of community classification based on TWINSPAN showed three categories of vegetation communities in the surveyed region: Quercus acuta community-I, Q. acuta community-II, and Neolitsea sericea-Aphananthe aspera community. In the evergreen broad-leaved forest in the Duryunsan Provincial Park, Q. acuta dominant in the canopy were expanding their presence in the understory. In addition to the Q. acuta, N. sericea and Cinnamomum yabunikkei, which are evergreen broad-leaved trees of the canopy, were found in all layers. The deciduous broad-leaved trees such as Q. variabilis, Q. serrata, and Carpinus tschonoskii were culled, and the transition to Q. acuta evergreen broad-leaved trees was ongoing. N. sericea community appeared locally. The species diversity index of N. sericea-A. aspera community was lower at 1.0798 than that of Q. acuta Community-I at 1.3208 and Q. acuta Community-II at 1.4916.