• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.70-78
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• 2017

The Hwasan wetland vegetation is observed at mountain basin (644~780 m a.s.l.) where had become a potential land for indigenous people since prehistoric period. We phytosociologically investigated old-growth alder (Alnus japonica) forests using the $Z\ddot{u}rich$-Montpellier School's method and analyzed their spatial distribution pattern by actual vegetation map. Species performance was determined by using coverage and r-NCD. Viburnum opulus var. calvescens-Alnus japonica community syntaxonomically belonging to the Alnetea japonicae was first described and composed of three subunits: Salix koreensis subcommunity, typical subcommunity, and Pyrus ussuriensis subcommunity. Present plant community was compared with vicariant syntaxa such as Molinia japonica-Alnus japonica community, Rhamno nipponicae-Alnetum japonicae, and Aceri-Salicetum koreensis. Hwasan's alder forest, an alluvial terrace vegetation type on valley fan in the montane zone, is evaluated as vegetation class [I], which is a sort of benchmark plant community potentially on mountain wetlands in southeastern part of the Korean Peninsula. Simultaneously we suggested an establishment of the national strategy for habitat conservation free from hydrologically radical transform due to military utilization.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1352-1359
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• 2018

Lactobacillus plantarum is a lactic acid bacterium that promotes animal intestinal health as a probiotic and is found in a wide variety of habitats. Here, we investigated the genomic features of different clusters of L. plantarum strains via pan-genomic analysis. We compared the genomes of 108 L. plantarum strains that were available from the NCBI GenBank database. These genomes were 2.9-3.7 Mbp in size and 44-45% in G+C content. A total of 8,847 orthologs were collected, and 1,709 genes were identified to be shared as core genes by all the strains analyzed. On the basis of SNPs from the core genes, 108 strains were clustered into five major groups (G1-G5) that are different from previous reports and are not clearly associated with habitats. Analysis of group-specific enriched or depleted genes revealed that G1 and G2 were rich in genes for carbohydrate utilization (${\text\tiny{L}}-arabinose$, ${\text\tiny{L}}-rhamnose$, and fructooligosaccharides) and that G3, G4, and G5 possessed more genes for the restriction-modification system and MazEF toxin-antitoxin. These results indicate that there are critical differences in gene content and survival strategies among genetically clustered L. plantarum strains, regardless of habitats.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.6
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• pp.1-14
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• 2020

Under the 「National Land Planning and Utilization Act」, Development Restriction Zones(DRZ) is one of the designated use district where the Minister of Land, Infrastructure and Transport deems it necessary to control urban development in order to prevent urban sprawl and conurbation and ensure a healthy living environment for citizens by conserving the natural environment surrounding metropolitan cities. DRZ was first designated around the Seoul Metropolitan city in 1971, and had been expanded to the 14 metropolitan areas across the country since 1977. The designated areas were accounted for about 5.4% of the total national land and its importance was demonstrated by contributing to control urban sprawl, curbing real estate speculation, and providing green space to citizens. However, DRZ has been repeatedly relaxed its regulations and allowed development under government. As a result, much of the green areas was damaged and several cities were merged and extended(conurbation). In particular, deregulation implemented for the purpose of securing land as part of national projects and local outstanding business(i.g. constructions of national rental housing, industrial complex, and international stadium) have caused continuous environmental damage around the metropolitan cities. In addition, the habitat fragmentation is in serious situation. Thus, the systematic plans for managing DRZ are necessary, since it is concerned that urban environment become deteriorate in the mid- to long-term. This study aims to continuously protect the urban environment from lifting DRZ. Therefore, firstly, we examined the environmental status through analyzing DRZ Management Plan which shall be drawn up by the Special Metropolitan City Mayor, the Metropolitan City Mayor or the Mayer/Do governor having jurisdiction, every five years to collectively manage DRZ. Secondly, we investigated the actual condition in DRZ based on the case study of Management Plan in Metropolitan areas(i.e. Seoul Metropolis, Gyeonggi-do, and Incheon Metropolis). Finally, we suggested the seven feasible improved political plan for managing DRZ.

• Journal of the Korean Geotechnical Society
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• v.39 no.6
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• pp.13-19
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• 2023

Lunar ice is a resource available for future human exploration in deep space and long-term extraterrestrial habitat. However, the origin and nature of lunar ice remains unclear. In addition to remote sensing, international space agencies are competitively planning and conducting missions for lunar surface exploration to determine the existence and resource extent of lunar ice. If a sufficient amount of lunar ice is confirmed, its future in-situ resource utilization is expected to be greatly beneficial. However, due to ice extraction, settlement may occur, which should be taken into account from a geotechnical engineering perspective. Herein, experimental investigations of the potential settlement caused by lunar ice extraction were conducted and different textures of lunar ice were simulated. Consequently, it was confirmed that significant settlement occurs even at the initial water content of ~10% in lunar regolith simulant-ice-mixed soil.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.89-90
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• 2021

Undersea bases built in the deep sea are built in more extreme environments than in space. In addition, it requires the convergence of mechanics, electronics, shipbuilding, meteorology, and diving science, marine physics, chemistry, biology, and geology. Undersea base can be constructed through the fusion of various technologies. The development of extreme technology for undersea construction will be the most advanced technology in each field, and it will be applied to space and other fields, so it will be an opportunity to preempt the latest technology.

• Korean Journal of Environment and Ecology
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• v.27 no.1
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• pp.11-21
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• 2013

We tried to find out the core feeding site of the Red-crowned Crane(Grus japonensis) in Cheorwon, Korea by using analysis techniques which are MCP(minimum convex polygon), KDE(kernel density estimation), LoCoH(local nearest-neighbor convex-hull). And, We discussed the difference and meaning of result among analysis methods. We choose the data of utilization distribution from distribution map of Red-crowned Crane in Cheorwon, Korea at $17^{th}$ February 2012. Extent of the distribution area was $140km^2$ by MCP analysis. Extents of core feeding area of the Red-crowned Crane were $33.3km^2$($KDE_{1000m}$), $25.7km^2$($KDE_{CVh}$), $19.7km^2$($KDE_{LSCVh}$), according to the 1000m, CVh, LSCVh in value of bandwidth. Extent, number and shape complexity of the core area has decreased, and size of each core area have decreased as small as the bandwidth size(default:1000m, CVh: 554.6m, LSCVh: 329.9). We would suggest the CVh value in KDE analysis as a proper bandwidth value for the Red-crowned crane's core area zoning. Extent of the distribution range and core area have increased and merged into the large core area as a increasing of k value in LoCoH analysis. Proper value for the selecting core area of Red-crowned Crane's distribution was k=24, and extent of the core area was $18.2km^2$, 16.5% area of total distribution area. Finally, the result of LoCoH analysis, we selected two core area, and number of selected core area was smaller than selected area of KDE analysis. Exact value of bandwidth have not been used in studies using KDE analysis in most articles and presentations of the Korea. As a result, it is needed to clarify the exact using bandwidth value in KDE studies.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.270-283
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• 2017

In a survey on higher fungi from 2004 to 2011, and also in 2013, in Naejangsan National Park, a total of 2 divisions, 7 classes, 21 orders, 74 families, 229 genera, and 521 species were observed. Dominant species belonged to the families Boletaceae and Russulaceae (44 species), Agaricaceae (35 species), Polyporaceae (29 species), and Amanitaceae (27 species). For the habitat environment, 21 families, 44 genera, and 192 species (36.9%) (63 species of poisonous mushroom, 79 species of edible and medicinal mushroom, and 43 species of unknown edible & poisonous mushroom) of ectomycorrhizal mushrooms were found; 41 families, 118 genera, and 199 species (38.2%) (14 species of poisonous mushroom, 85 species of edible & medicinal mushroom, and 90 species of unknown edible and poisonous mushroom) of litter decomposing and wood rotting fungi were found, and 29 families, 66 genera, and 121 species (23.2%) (8 species of poisonous mushroom, 54 species of edible and medicinal mushroom, and 47 species of unknown edible & poisonous mushroom) of grounding fungi were found, and 9 species were the other habitat. In terms of seasonality, most of the higher fungi were found in July, August, and September. In terms of altitude, the most species were observed at 200~299 m, and populations dropped by a significant level at an altitude of 700 m or higher. It seemed that the most diversified higher fungi occurred at climate conditions with a mean air temperature of $25.0{\sim}28.9^{\circ}C$, a maximum air temperature of $30.0{\sim}33.9^{\circ}C$, a minimum air temperature of $21.0{\sim}24.9^{\circ}C$, a relative humidity of 73.0~79.9%, and over 400.0 mm of rainfall.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.147-152
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• 2012

This study was conducted to investigate the photosynthetic R. micranthum by natural habitats. In the results, natural habitats didn't affect values of light saturated point, light compensation point and photosynthetic capacity of R. micranthum. We investigated light response curve and chlorophyll content at each habitat. Light compensation points were 11.8 ${\mu}mol\;m^{-2}\;s^{-1}$, 11.5 ${\mu}mol\;m^{-2}\;s^{-1}$ and 10.4 ${\mu}mol\;m^{-2}\;s^{-1}$ in Seokpo-ri, Yeonha-ri, and Mt. Worak. Light saturation points showed that R. micranthum is shade tolerant specie which has the light saturation point approximately 500~600 ${\mu}mol\;m^{-2}\;s^{-1}$. Photosynthetic rates of R. micranthum leaves were 5.5 ${\mu}mol\;m^{-2}\;s^{-1}$, 5.4 ${\mu}mol\;m^{-2}\;s^{-1}$ and 5.6 ${\mu}mol\;m^{-2}\;s^{-1}$ in Seokpo-ri, Yeonha-ri and Mt. Worak. On the other hand, since between $20^{\circ}C$ and $30^{\circ}C$, it appeared that the values of net photosynthetic rates of R. micranthum leaves in all sites were high. Especially, the rates were highest at $25^{\circ}C$. Because of low stomatal transpiration rate in saturation radiance, the moisture utilization efficiency in Yeonha-ri was lower than other habitats. Rates of chlorophyll a, chlorophyll b, and total chlorophyll content in Mt. Worak were no significant difference. Therefore R. micranthum has characteristic of shade tolerant species. The moderate temperature for R. micranthum is between $20^{\circ}C$ and $30^{\circ}C$.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1113-1124
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• 2009

The abandoned channel restoration is one of methods to enhance the environmental function and ecological habitat as well as the functions of water-utilization and flood control. The channel-forming or dominant discharge must be evaluated and defined to design the cross-sectional and plane geometries of the stable and equilibrium channel for the abandoned channel restoration project. In general, bankfull discharge, specified recurrence interval discharge, and effective discharge have been used to decide the channel-forming discharge. In this study, bankfull discharge, specified recurrence interval discharge, and effective discharge were calculated and compared for the abandoned channel restoration site of Cheongmi Stream and their relations to historical bed changes were analyzed. The bankfull discharge, 488 $m^3/s$, of the abandoned channel restoration site of Cheongmi Stream was calculated using HEC-RAS data and ranged between 1.5-year and 2-year recurrence discharges. Also, the effective discharge evaluated with the sediment rating curve and mean daily discharge data is greater than the bankfull discharge. According to the survey data of 1994 and 2008, the bed elevation of the study reach was decreased over time. It is indicated that the channel bed is changing to the stable condition to allow the effective discharge.

• Korean Journal of Environment and Ecology
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• v.34 no.3
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• pp.224-234
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• 2020

This study was conducted to investigate the vegetation structure of Zone 2 of Mudeungsan National Park Old Trail. A total of 60 survey plots were installed to survey the forest structure, and TWINSPAN and DCA analysis classified them into 5 communities. The community I was classified into Deciduous broad-leaf tree, II into Pinus densiflora-Quercus serrata, III into Quercus serrata, IV into Lindera erythrocarpa, and V into Quercus mongolica. The grouped communities showed some differences in species compositions according to elevation. In the four communities except for community IV, Styrax japonicus and Sasa borealis formed a dominant population in understory layers and in shrub layers, respectively, and the current community forms are expected to be maintained. Monitoring of vegetation succession of lower vegetation after temporary flowering and withering in the ridges developed in the shrub layers in communities II through IV is required. In the long-term aspect, the competition between the pine tree and oak tree communities requires observation of a decrease in the power of the pine tree community. Mudeungsan National Park's Old Trail ecologically valuable as it has a vegetation structure that is distinctively classified according to altitude and is a habitat of Lindera sericea, the flagship species of Mudeungsan National Park. It means that the excellent forest ecosystem of Old Trail must be conserved through sustainable utilization.