• Korean Journal of Environment and Ecology
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• v.37 no.1
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• pp.1-12
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• 2023

We analyzed the distribution area of debris slopes in Mudeungsan (Mt. Mudeung) National Park by comparing aerial photos of the past (1966) and the present (2017) and identified the vegetation characteristics that affect the change in the area of the debris slopes by investigating the vegetation status of the debris slopes and the surrounding areas. The area of debris slopes in Mt. Mudeung appears to have been reduced to a quarter of what it used to be. Debris slopes here have decreased at an average rate of 2.3 ha/yr over 51 years by vegetation covers. Notably, most of the small-area debris slopes in the low-inclination slopes disappeared due to active vegetation coverage. However, there are still west-facing, south-west-facing, south-facing, and large-area debris slopes remaining because the sun's radiant heat rapidly raises the surface temperature of rock blocks and dries moisture, making tree growth unfavorable. Because of these locational characteristics, the small-scale vegetation in the middle of Deoksan Stony Slope, which is the broadest area, showed distinct characteristics from the adjacent forest areas. Sunny places and tree species with excellent drying resistance were observed frequently in Deoksan Stony Slope. However, tree species with high hygropreference that grow well in valleys with good soil conditions also prevailed. In some of these places, the soil layer has been well developed due to the accumulation of fine materials and organic matter between the crevices of the rock blocks, which is likely to have provided favorable conditions for such tree species to settle and grow. At the top of Mt. Mudeung, on the other hand, the forest covered the debris slopes, where Mongolian oaks (Quercus mongolica) and royal azaleas (Rhododendron schlippenbachii), which typically grow in the highlands, prevailed. This area was considered favorable for the development of vegetation for the highlands because the density of rock blocks was lower than in Deoksan Stony Slope, and the soil was exposed. Moreover, ash trees (Fraxinus rhynchophylla) and Korean maple trees (Acer pseudosieboldianum) that commonly appear in the valley areas were dominant here. It is probably due to the increased moisture content in the soil, which resulted from creating a depressive landform with a concave shape that is easy to collect rainwater as rock blocks in some areas fell and piled up in the lower region. In conclusion, the area, density of the rock blocks, and distribution pattern of rock block slopes would have affected the vegetation development and species composition in the debris slope landform.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.539-546
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• 2016

The aim of this study was to analyze antioxidant activity, total phenolics, and vitamin C content in unripe and ripe jujube cultivar and to investigate correlation between antioxidant and chemical constituents including total phenolics and vitamin C. The antioxidant activity was measured by the DPPH radical scavenging activity, ABTS radical scavenging activity, and reducing power. Although, the weight, diameter and soluble solids of Zyziphus jujuba fruit were increased with the progress of ripening, antioxidant activity and total phenolics were decrease during ripening. The highest free-radical scavenging activity (at 2.5 ㎎/㎖) and reducing power (at 1 ㎎/㎖) in fruit were 81.75% (Bokjo, unripe) and 0.80 (Mudeung, unripe), respectively. The highest total phenolic content in unripe fruit of Mudeung was 62.50 ㎍/g. A linear correlation (r=0.911) was shown between DPPH radical scavenging activity and total phenolic content.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.904-909
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• 2005

To optimize the removal of free fatty acid in crude vegetable oil, response surface methodology was applied to determine the effects of five level-four factors and their reciprocal interactions on removal of free fatty acid. A total of 30 individual experiments were performed, which were designed to study reaction temperature, reaction time, catalyst amount and methanol amount. A statistical model predicted that the highest removal yield of free fatty acid was 99.8%, at the following optimized reaction conditions: a reaction temperature of 64.99$^{\circ}C$, a reaction time of 36.20 mins., an catalyst amount of 13.01% (w/v), and a methanol amount of 15% (v/v). Using these optimal factor values under experimental conditions in three independent replicates, the average removal yield was well within the value predicted by the model.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.1 s.6
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• pp.83-91
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• 1996

With the growth of cities, there is a nero today for construction of outer road of cities but there are many problems in executing the scheme. In this study 5 kilos' distance, a part of the first section from East Kwangju I.C. in 36kilos' distance, the road circling Other Kwangju city is determined as the object of this study and illustrated by GIS. Besides that, the landscape which is varied according to survey location is illustrated each section by using data such as plans and 1he planed height. and the area for this study which is circling around Mt. Mudeung, a noted in Kwangju city is represented by GIS.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.65-75
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• 2004

This study aims to identify the degree of heat island in summer in Gwangju. For the purpose the city was classified according to use and surface components and temperature of the city for 24 hours was measured. The period of measurement was from August 11 to 13. 2003(two days). As a result of the measurement, the daily standard temperature of the central business areas and downtown areas was about $26^{\circ}C$. That of new residential areas neighboring the downtown was $25.1^{\circ}C$, and that of the outer residential areas was $23.4^{\circ}C$. In comparison with the result that temperatures of the Gwangju University playground and the Gwangju Weather Bureau were $23.1^{\circ}C$ and $23.3^{\circ}C$ respectively, the temperature of the downtown was about $2.7^{\circ}C$ Higher and that of the new residential area in downtown was about $1.8^{\circ}C$ higher. And it was demonstrated that the downtown outer road under Mt. Mudeung is a low-temperature zone. When temperature of the city was measured based on surface components, the daily standard temperature of Gwangju Stream Bok-gae area was the highest, $24.2^{\circ}C$, followed by $23.6^{\circ}C$ of the downtown stream and $22.2^{\circ}C$ of the greens (city park) and the waterside area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.3
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• pp.117-126
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• 1985

The object of this study is experimental determination of the refraction coefficient(K) which is critical factor in the zenith distance measurement of precision trigonometrical leveling. Thus, the characteristics of seasonal, directional and daily variation of the refraction coefficients according to each district were presented in this paper. Comparing K value by the observed zenith distance with that calculated from the temperature gradient observed at Mt. Mudeung, we obtained satisfactory results.

• Korean Journal of Plant Taxonomy
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• v.38 no.4
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• pp.565-571
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• 2008

In the course of execution for Inventories and Management of Plant Resources of Korea, We found new habitats of 4 plant species which distribution ranges are obscure and/or extremely restricted. A subtropical fern distributed in Jeju-do, Woodwardia japonica (L. f.) Sm., was found in Mt. Gambang-san of Hampyeong-gun, Jeollanam-do. A saprophytic orchid, Galeola septentrionalis Reichb., was found in Mt. Ggachi-bong of Boseong-gun, Jeollanam-do. Peristrophe japonica (Thunb.) Bremek., known in Jeollanam-do, was newly found in Mt. Mudeung-san of Gwangju-si. Viburnum furcatum Blume mainly distributed in Jeju-do and Ulleung-do was found in Mt. Jabyeong-san of Gangneung-si, Gangwon-do.

• Journal of Environmental Science International
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• v.31 no.5
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• pp.431-445
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• 2022

The Gwangju Stream is a major tributary of the Yeongsan River. To maintain environmental and ecological functions in the stream, the flow is secured by natural water from the Mudeung Mountain as well as waters discharged from Lake Juam and the Gwangju sewage treatment plants. A substantial amount of water is supplied into the upper reaches of Gwangju Stream from Lake Juam. To examine the ecological effects of the water input from Lake Juam on the Gwangju Stream, a field survey of phytoplankton community species and an evaluation of water properties was conducted at five stations, from station GJ1 before the inflow to station GJ5 in the lower region. Nutrient levels decreased in the vicinity of the Lake Juam inflow, suggesting that this water inflow can contribute to the reduction of eutrophication in the stream. The phytoplankton community was mainly composed of Bacillariophyceae, Chlorophyceae, and Cyanophyceae, and the community structure was similar to that of the other study sites located near the water inflow regions. The inflow of water from Lake Juam can affect water quality and the phytoplankton community over a limited area, reducing eutrophication and increasing water flow in the Gwangju Stream.

• The Korean Journal of Community Living Science
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• v.16 no.3
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• pp.37-45
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• 2005

This study was conducted to investigate the utilization of cut pear branches for dyeing materials, and the dyeability of pear flowers for pressed flowers using red, orange, and green edible pigments. There was a significant difference of E values among 0.1, 0.5 and $1.0{\%}$ diluted solutions of edible pigments for the cut pear branches coming into flowers. In the higher concentrations of dyeing solutions and the longer dyeing periods, a values with the red pigments increased from 2.37 to 31.22, b values with the orange pigments increased from 7.04 to 45.85, and a - values with the green pigments increased from -3.88 to -36. Bloomed pear branches were immersed in diluted solutions with red, orange and green pigments for forty five minutes. Pear branches immersed in $0.1{\%}$ and $0.5{\%}$ diluted solutions bloomed normally, and each of the flowers were dyed in the colors of the dyeing solutions, respectively. The dyeability of the bloomed pear branches immersed in water and dyeing solutions for one hundred and twenty minutes decreased compared with those treated with red, orange and green pigments and dyed immediately. The dyeability of flowers for the cut pear branches dyed immediately after cutting was significantly increased compared with that immersed in water and dyeing solutions.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.333-339
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• 2013

In this study we investigated the relationship between characteristics of vegetative growth of three species of Viola (V. rossii, V. japonica, and V. dissecta var. chaerophylloides) and light in order to explain how these three species could live together under a closed space in a forest. This studywas carried out at five sites in Mudeung-san (Mt.) on 1994, 1995, and 2000 and additional investigations were performed on 2007 and 2010 at the same sites. In order to find the relationship, three main investigations were conducted: counting number of individuals for each investigated year, measuring dry mass and counting developed leaves per plant, and finding presenting patterns of each species with reference to incidence of light. As a result, we found that three species could share the closed space in a forest because of their different adaptive strategies like V. rossii as Kstrategist, V. japonica as r-strategist, and V. dissecta var. chaerophylloides as an intermediator between two species.