• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.6-19
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• 2009

We investigated the macrozoobenthos at major two harbors of Korea in July and August 2007 in order to check the changes in the species composition due to the invasive species and to make a species inventory at each harbor system. At the Incheon Harbor, a total of 88 species was sampled with abundance of 3,212 ind. m$^{-2}$ and biomass of 239 g m$^{-2}$. The most dominant species was Tharyx sp. belong to polychaete taxa, followed by Chaetozone setosa in the harbor area. The dominant species of outer area were Musculus senhousia and Sternaspis scutata. The diversity index ranged between 0.9$\sim$2.4, and evenness index between 0.3$\sim$0.9, and richness index between 1.8$\sim$3.9. Benthic pollution index ranged between 16$\sim$74. The highest benthic pollution index was at station 4. On the other hand the lowest value was at station 6, where a large amount of M. senhousia belong to mollusca occurred. At the Busan Harbor, a total of 89 species was sampled with density of 1,845 ind. m$^{-2}$ and biomass of 133.6 g m$^{-2}$ in August 2007. The most dominant species was Tharyx sp., followed by M. japonica and Cirratulus cirrata within harbor area. M. japonica was dominant species in the outer area. The diversity index ranged between 0.7$\sim$2.2, evenness index between 0.3$\sim$1.0, and richness index between 1.1$\sim$4.1. Benthic pollution index ranged between 31$\sim$90. The lowest benthic pollution index was found at site 2 within harbor area.

• Korean Journal of Heritage: History & Science
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• v.53 no.2
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• pp.254-269
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• 2020

The purpose of this study is to propose guidance for wall renewal that is appropriate for an ancient city wall through application of advanced research and theories in wall design. It is a streetscape improvement project which forms part of the "Ancient City Image Finding Project". Study methods consist of advanced research classification, wall design theory contemplation, and analysis of the significance of designated ancient city areas and the "Ancient City Image Finding Project" status. Based on these methods, case study candidates were selected, case status and problems were identified, and improvement proposals were analyzed by comparing various features. Advanced wall research was classified into six categories including analysis of wall characteristics; wall design principle applications; wall structure, color, shape, and application; modern reinterpretation; palace walls; and house, temple, and village walls. The wall is an element of the streetscape improvement component of the "Ancient City Image Finding Project", with the characteristic of providing preceding experience in visual and cognitive awareness than interior structure. Case candidates for ancient city wall improvement are based on the composition distribution of the special conservation district in each ancient city as well as the conservation promotion district. Ultimately, the surrounding village of Gongju-si Geumseong-Dong Songsanri-gil, adjacent to the Royal Tomb of King Muryeong, was selected as the candidate. The "Ancient City Image Finding Project" of the surrounding village of Gongju-si Geumseong-Dong Songsanri-gil began with new Hanok construction. However, wall maintenance did not begin concurrently with that new Hanok construction. Support and maintenance took place afterwards as an exterior maintenance project for roadside structures. If the Hanok and wall were evaluated and constructed at the same time, the wall would have been built in unison with the size and design of the Hanok. The layout of the main building and wall of the Hanok is deemed to be a structure that is closed tightly because of its spatial proximity and tall height. Songsan-ri-gil's wall design should create a calm, subtle, and peaceful atmosphere with shapes, colors, and materials that express ancient city characteristics, but it is in an awkward position due to its sharpness and narrowness. The cause of the problem at Gongju-si Geumseong-dong Songsanri-gil, the case candidate, is that it is lacking significantly in terms of the aesthetic factors that traditional walls should possess. First, aesthetic consciousness seems to have disappeared during the selection and application process of the wall's natural materials. Second, the level of completion in design and harmony is absent. Maintenance guidance after analyzing the cause of problems in ancient city wall maintenance at Gongju-si Geumseong-dong Songsanri-gil, the subject area of research, is as follows: First, the Hanok design and layout of the wall and main gate should be reviewed simultaneously. Second, the one-sided use of natural stone wall in the Hanok wall design should be reexamined. Third, a permanent system to coordinate the opinions of citizens and experts during the planning and design phases should be employed. Fourth and finally, the Hanok's individuality shall be collectivized and its value as a cultural asset representing the identity of the community shall be increased.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.116-124
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• 2006

In this study was performed to analyze quantitatively the number of viable but non-culturable bacteria in the Pine and Quercus forest soil by improved direct viable count (DVC) and plate count (PC) methods. The number of living bacteria of Pine and Quercus forest soil by PC method were less then 1% of DVC method. This result showed that viable but non-culturable (VBNC) bacteria existed in the forest soil with high percentage. Diversity and structure of VBNC bacterial populations in forest soil were analyzed by direct extracting of DNA and 16S rDNA-ARDRA from Pine and Quercus forest soil. Each of them obtained 111 clones and 108 clones from Pine and Quercus forest soil. Thirty different RFLP types were detected from Pine forest soil and twenty-six different RFLP types were detected from Quercus forest soil by HeaIII. From ARDRA groups, dominant clones were selected for determining their phylogenetic characteristics based on 16S rDNA sequence. Based on the 16S rDNA sequences, dominant clones from ARDRA groups of Pine forest soil were classified into 7 major phylogenetic groups ${\alpha}$-proteobacteria (12 clones), ${\gamma}$-proteobacteria (3 clones), ${\delta}$-proteobacteria (1 clone), Flexibacter/Cytophaga (1 clone), Actinobacteria (4 clones), Acidobacteria (4 clones), Planctomycetes (5 clones). Also, dominant clones from ARDRA groups of Quercus forest soil were classified into 6 major phylogenetic groups : ${\alpha}$-proteobacte,ia (4clones), ${\gamma}$-proteobacteria (2 clones), Actinobacteria (10 clones), Acidobacteria (8 clones), Planctomycetes (1 clone), and Verrucomicobia (1 clone). Result of phylogeneric analysis of microbial community from Pine and Quercus forest soils were mostly confirmed at uncultured or unidentified bacteria, VBNC bacteria of over 99% existent in forest soil were confirmed variable composition of unknown micro-organism.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.1040-1046
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• 2010

This research is composed of a series of survey of existing plants species by classifying biotope type of agro-ecosystem of Guksoo village area of Yangpyeong County, to collect and analyze basic data of vegetation analysis for indicators development of agro-ecosystem habitat quality. From the observation area, we found total 141 kinds of tracheophytes (53 Family 114 Genus 124 Species 16 Variety 1 Breed) and they are 3.36% of total Korean tracheophytes (4,191 kinds). Among those 141 tracheophytes, there are 23 kinds of naturalized plants (11 Family 20 Genus 20 Species 2 Variety) and they are 8.61% of total Korean naturalized plants (267 kinds). Among those 141 tracheophytes, they include 0.71% of pteridophyte, 0.71% of gymnosperm, 98.58% of angiosperm. So, most of them are angiosperm. When we classify them according to plant life form characteristics, dormant/diapause type plants include 45 species (31.91%) of annual plant (Th), 19 species (13.48%) of Th (w), 17species (12.06%) of hemicryptophyte (H). Regarding propagation type, as for the Radicoid form, there are 99 species (70.21%) of crumb structure plant, 13 species (9.22%) of $R_4$, 12 species (8.51%) of $R_{2.3}$ are the crumb structure does not make any connection on the ground or under ground. As for the Disseminule form of propagation type, there are 62 species (43.97%) of Gravity dispersal type $D_4$), 23 species (16.31%) of Wind dispersal type ($D_1$), 21 species (14.89%) of $D_{1.4}$. According to this survey of plant distribution rate by plant life form characteristics, we may acquire many knowledge about species composition of sociability, cluster's reaction against environmental elements, space usage and possible species competition in community. It may be very useful basic data for habitat preservation to keep and promote biological diversity.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.208-227
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• 2013

Twenty-seven bronze bowls excavated from the Goryo burial complex at Deobu-gol were examined for their microstructure and chemical composition to characterize the bronze technology practiced by commoners at the time. Results showed that the objects examined can be classified into four groups: 1) objects forged out of Cu-near 22%Sn alloys and then quenched; 2) objects cast from Cu-below 10% Sn alloys containing lead; 3) objects cast from Cu-10%~20% Sn alloys containing lead and then quenched; 4) objects forged out of Cu-10~20% Sn alloys containing lead and then quenched. This study revealed that the fabrication technique as determined by alloy compositions plays an important role in bronze technology. The use of lead was clearly associated with the selection of quenching temperatures, the character of inclusions and the color characteristics of bronze surfaces. It was found that the objects containing lead were quenched at temperatures of $520^{\circ}{\sim}586^{\circ}C$ while those without lead were quenched at the range of $586^{\circ}{\sim}799^{\circ}C$. The presence of selenium in impurity inclusions was detected only in alloys containing lead, suggesting that the raw materials, Cu and Sn, used in making the lead-free alloys for the first group were carefully selected from those smelted using ores without lead contamination. Furthermore, the addition of lead was found to have significant effects on the color characteristics of the surface of bronze alloys when they are subjected to corrosion during interment. In leaded alloys, corrosion turns the surface light green or dark green while in unleaded alloys, corrosion turns the surface dark brown or black. It was found that in fabrication, the wall thickness of the bronze bowls varies depending on the application of quenching; most of the quenched objects have walls 1mm thick or below while those without quenching have walls 1mm thick or above. Fabrication techniques in bronze making usually reflect social environments of a community. It is likely that in the late Goryo period, experiencing lack of skilled bronze workers, the increased demand for bronze was met in two ways; by the use of chief lead instead of expensive tin and by the use of casting suitable for mass production. The above results show that the Goryo bronze workers tried to overcome such a resource-limited environment through technological innovations as apparent in the use of varying fabrication techniques for different alloys. Recently, numerous bronze objects are excavated and available for investigation. This study shows that with the use of proper analytical techniques they can serve as a valuable source of information required for the characterization of the associated technology as well as the social environment leading to the establishment of such technology.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.92-105
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• 2019

Spatial and temporal characteristics of phytoplankton communities around the coastal waters of Jeju Island were investigated with environmental factors such as water temperature, salinity, and dissolved oxygen. Monthly samples were collected at 0 and 30 m depths of 10 stations from March 2015 to February 2016. During the survey period, water temperature ranged in 13.7~25.9 and $13.6{\sim}20.8^{\circ}C$ at 0 and 30 m, salinity in 31.51~34.47 and 33.03~34.47 psu at 0 and 30 m, and dissolved oxygen in 6.12~8.10 and $5.73{\sim}7.88mg\;L^{-1}$ at 0 and 30 m, respectively. Chlorophyll-a ranged in 0.28~2.48 and $0.44{\sim}1.01{\mu}g\;L^{-1}$ at 0 and 30 m, respectively. Phytoplankton abundance fluctuated in the range of $5,300{\sim}639,900cells\;L^{-1}$ during the year, showing the lowest in February at all stations, and the highest in July at the northern and western sea as well as in August at the southern and eastern sea of Jeju Island. A total of 362 species were occurred including 181 spp. of Bacillariophyta, 147 spp. of Dinophyta and 34 spp. of other phytoflagellates. Dominant species with occupancy rate over 20 percent of phytoplankton abundance showed apparent seasonal succession such as Paralia sulcata and Skeletonema costatum in spring and autumn, 6 spp. of genus Chaetoceros in summer, and 2 spp. of genus Chaetoceros and Thalassionema frauenfeldii in winter. Monthly abundance in the northern and western sea fluctuated with similar tendency, and the southern and eastern sea also showed similar pattern of monthly abundance variation. Species composition and dominant species succession mentioned above were quite different from previous studies, so some physical changes such as water temperature, salinity and current pattern might cause the changes of phytoplankton assemblages around Jeju Island.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.377-386
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• 2021

This study was conducted to provide basic data for habitat management and preservation of Jeongmaek. A total of 18 priority research areas were selected with consideration to terrain and habitat environment, and 54 fixed plots were selected for three types of habits: development, valley, and forest road and ridge. The survey was conducted in each season (May, August, and October), excluding the winter season, from 2016 to 2018. The distribution analysis of birds observed in each habitat type using a self-organizing map (SOM) classified them into a total of four groups (MRPP, A=0.12, and p <0.005). The comparative analysis of the number of species, the number of individuals, and the species diversity index for each SOM group showed that they were all the highest in group III (Kruskal-Wallis, the number species: x² = 13.436, P <0.005; the number of individuals: x² = 8.229, P <0.05; the species diversity index: x² = 17.115, P <0.005). Moreover, the analysis by applying the land cover map to the random forest model to examine the index species of each group and identify the characteristics of the habitat environment showed a difference in the ratio of the habitat environment and the indicator species among the four groups. The index species analysis identified a total of 18 bird species as the indicator species in three groups except for group II. When applying the random forest model and indicator species analysis to the results of classification into four groups using the SOM, the composition of the indicator species by the group showed a correlation with the habitat characteristics of each group. Moreover, the distribution patterns and densities of observed species were clearly distinguished according to the dominant habitat for each group. The results of the analysis that applied the SOM, indicator species, and random forest model together can derive useful results for the characterization of bird habitats according to the habitat environment.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.559-572
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• 2021

A survey was conducted to analyze water masses and spatial distributions of phytoplankton communities at 15 stations on the surface and chlorophyll a maximum layers (CML) in the western South Sea of Korea from September 8 to 9, 2021. As a result, water masses were classified into Coastal Waters (CW) with relatively low salinity, the Tsushima Warm Current (TWC) with high water temperature and high salinity, and mixed waters (MW) showing a mixture of these two water masses. Turbidity showed high concentration in both the surface and CML. The chlorophyll a concentration was as low as 0.90±0.43 ㎍ L^-1 in the surface, more than 1.1 ㎍ L^-1 in CW, around 1.0 ㎍ L^-1 in MW, and less than 0.5 ㎍ L^-1 in the TWC. CML was 1.64±0.54 ㎍ L^-1. Regarding species composition of phytoplankton communities, there were 57 species in 31 genera(diatoms, 57.8%; dinoflagellates, 35.1%; and other phytoflagellates, 7.1%). The phytoplankton standing crop had 4.6±7.6 cells mL^-1 in the surface, more than 30 cells mL^-1 in the CW, 2-5 cells mL^-1 in the MW, and less than 2 cells mL^-1 in the TWC. CML was slightly higher than the surface with a variation of 5.7±8.4 cells mL^-1. Dominant species were found to be Rhizosolenia flagilissima f. flagilissima, Skeletonema costatum-ls, and Nitzschia sp./ small size in the surface. For the CML Rh. flagilisima f. flagilissima showed a dominance of 12.0%. For the surface, the diversity variation was 2.36±0.40, which was high for TWC but low for MW. For CML, the diversity variation was 2.29±0.52, which was slightly lower than that of the surface. The dominance in the surface was 0.50±0.15, with a fluctuation range of more than 0.5 in MW and less than 0.5 in the TWC, which was different from the diversity. According to correlation analysis and principal component analysis (PCA), the presence of phytoplankton standing crops was high in CW but low in MW and TWC. That is, phytoplankton communities in early autumn were strongly affected by the expansion and mixing of water masses in western South Sea.