• Journal of Environmental Science International
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• v.29 no.9
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• pp.915-924
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• 2020

The purpose of this study was to conduct a forest healing program for victims affected by the large forest fires of 2017 in Gangneung and to investigate its effects on the stress and physical health promotion of the victims. From January to March 2019, three forest therapy programs were conducted on 49 residents of four villages that suffered forest fires in the National Center for Forest Therapy, Daegwallyeong. The results showed that the degree of stress of forest fire victims decreased significantly by means of these programs. Furthermore, autonomic nerve activity, stress resistance, stress index, and fatigue decreased significantly and average heart rate and heart stability also improved.

• Journal of the Korean Wood Science and Technology
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• v.49 no.2
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• pp.142-153
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• 2021

Candida albicans is a dermal fungus of the human body that is known to cause oral candidiasis, vaginal candidiasis, and bloodstream infections in immunocompromised people or in certain environmental conditions. As cases of strains resistant to antifungal agents in C. albicans have been reported, studies using plant materials as safe antifungal agents are being actively conducted. In this study, a total of 17 edible plant extracts showed antifungal activity against C. albicans as a result of evaluating a 280-plant extract library using paper disk diffusion method. Among them, the four extracts with the strongest antifungal activity (Cinnamomi Cortex, Cinnamomi Ramulus, Magnoliae Cortex, and Syzygii Flos) were selected and evaluated for synergistic antifungal activity against C. albicans. The combination of Magnoliae Cortex and Syzygii Flos showed a synergistic activity. The antifungal activity was evaluated based on the concentrations of magnolol and eugenol, the respective components of Magnoliae Cortex and Syzygii Flos. Magnolol and eugenol showed synergistic antifungal activities at the concentration ratio of 1:25 - 1:61. The antifungal activity of these two compounds contributes 28 to 48% to the synergistic antifungal activity of the combination of Magnoliae Cortex and Syzygii Flos extract. In this study, we propose that a combination of Magnoliae Cortex and Syzygii Flos can effectively inhibit the growth of C. albicans and that magnolol and eugenol are the responsible inhibitory compounds.

• Journal of the Korean Wood Science and Technology
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• v.47 no.6
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• pp.751-760
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• 2019

Cellulase is an eco-friendly biocatalyst, and its demand is growing in many industrial applications such as food, textile, paper, and bioenergy. Strains with a high cellulase activities are the starting point for the economic production of cellulase. In a previous study, Acanthophysium sp. KMF001 with high cellulase production ability was selected among 54 wood-rotting fungi. In this study, we evaluated the cellulase productivity of Acanthophysium sp. KMF001 quantitatively and analyzed its taxonomic location using a genetic method. Acanthophysium sp. KMF001 showed high cellulase productivity similar to that of Acanthophysium bisporum and was much better than A. bisporum in specific enzyme activity. The 28S rRNA sequence of Acanthophysium sp. KMF001 was similar to that of Acanthophysium lividocaeruleum MB1825, with 98.40% homology. Phylogenetic analysis suggested that Acanthophysium sp. KMF001 is a new strain. In this study, we propose a new strain with high cellulase productivity.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.317-326
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• 2017

The wood and bark of Hawthorn tree (Crataegus pinnatifida Bunge) were immersed with 70% aqueous acetone for 3 days. After filtering, the wood extracts were fractionated with n-hexane, chloroform ($CHCl_3$), n-butanol (n-BuOH) and $H_2O$, and the bark extracts were fractionated with n-hexane, $CHCl_3$, ethylacetate (EtOAc) and $H_2O$. Then antioxidative and anti-inflammatory activities were evaluated on each fraction. Antioxidative activity indicated high activity in the n-butanol soluble fraction of wood and in the EtOAc soluble fraction of bark. Especially, the EtOAc soluble fraction of bark showed much higher antioxidative value compared to the controls, buthylated hydroxytoluene (BHT) and ${\alpha}$-tocopherol. In the anti-inflammatory activity, all of the tested fractions except the $H_2O$ soluble fraction of wood showed high inhibitory effect on nitric oxide (NO) production. Based on the above results, the extracts of hawthorn tree may be applied for one of the natural biomass sources that can be used as an antioxidant and an anti-inflammatory substance.

• Korean Journal of Plant Resources
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• v.20 no.5
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• pp.461-465
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• 2007

In this study, changes in the overall antioxidant properties and chemical constituents including total phenolics and vitamin C of R. occidentalis fruit during ripening are studied. The antioxidant activity was measured by the free-radical scavenging activity(DPPH method) and reducing power(potassium ferricyanide method). Although, the weight and diameter of R. occidentalis fruit were increased with the progress of ripening, antioxidant activity and total phenolics were decrease during ripening. The highest free-radical scavenging activity(at $125{\mu}g/m{\ell}$) and reducing power(at $100{\mu}g/m{\ell}$) in fruit were 61.67% and 0.71, respectively. Total phenolic content and vitamin C content in fruit of 5 days after fruit set were $220.73{\mu}g/g$ and $540.45{\mu}g/g$, respectively. A linear correlation(r=0.9761) was shown between free-radical scavenging activity and total phenolic content.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.51-57
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• 2002

Antimicrobial and antioxidative activites on heartwood extractives of domestic species were investigated to develop a natural fungicide or preservative. One steroid, stilbene derivatives and two flavonoids were isolated from heartwood of Robinia pseudo-acacia which has been selected due to its high antioxidative activity among the tested species. The structures were determinded as: 3-𝛽-stigmast-5-en-3-ol(daucosterol), 3,3'4,5-tetrahydroxystilbene, 3,3'4'5,7-pentahydroxyflavone(robinetin) and 3,3'4'7-tetrahydroxyflavanone(fustin) respectively on the basis of spectroscopic data and chemical correlations. According to the results of free radical scavenging activity, 3,3'4'5,7-pentahydroxyflavone was evaluated as the highest antioxidative compound among the four compounds and showed higher radical scavenging activity than those of 𝛼-tocopherol and butylated hydroxytoluene(BHT), one of the strongest synthetic antioxidants. 3,3'4'5-Tetrahydroxystilbene and 3,3'4'7-tetrahydroxyflavanone showed higher antioxidative activities than that of 𝛼-tocopherol. However, 3-𝛽-stigmast-5-en-3-ol did not show free radical scavenging activity. In this regard, it could inferred that high antioxidative activity of extractives of R. pseudo-acacia was derived from 3,3'4'5'7-pentahydroxyflavone, 3,3'4'5-tetrahydroxystilbene and 3,3'4'7-tetrahydroxyflavanone.

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.165-176
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• 2022

To raise awareness of carbon reduction in climate change, the Korea Forest Service has developed and adopted a forest carbon offset program, which aims to reduce carbon levels based on forest management. However, to maintain the forest carbon offset program, challenges such as the lack of a forest monitoring system to manage and maintain the program, must be faced. In this context, we investigated the limitations of conducting forest carbon offset programs using a number of interview techniques, including in-depth interview and questionnaire survey methods. The questionnaire surveys were developed based on the results of a literature review along with a preinterview and in-depth survey of the people in charge of the forest carbon offset program. The Irving Seidman technique was adopted for the in-depth interviews. Additionally, descriptive and frequency analyses were conducted to identify the characteristics of perception. Lastly, logistic regression was used to identify the limiting factors that affect the willingness to perform forest carbon offset monitoring activity. Results showed that the project managers or people in charge of the forest carbon offset program lacked expertise in forest carbon offset programs, which negatively affected their willingness to perform monitoring activity. Additionally, the study revealed a number of limiting factors that hindered the monitoring of forest carbon offset projects. Improving understanding using the approaches presented in this study may contribute to increasing the benefits associated with the forest carbon offset program in South Korea.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.236-249
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• 2015

The master plan of forest land management proposes forest watershed management that considers regional characteristics in order to overcome the problem of uniform forest land management. In order to manage the forest watersheds in Gyeonggi-do, this study classified 1,823 forest watersheds in Gyeonggi-do and attempted to understand their characteristics. It conducted a factor analysis and cluster analysis from the perspective of conservation value and development pressure using forest land indicators. In terms of conservation value, three factors were drawn: the topography factor, vegetation factor and public service factor, while in terms of development pressure, three factors were drawn: the easiness of development factor, economic benefits factor and development activity factor. Using these factors, forest watersheds were divided into three clusters in terms of conservation value while they were divided into three clusters in terms of development pressure. Using the results of the cluster analysis from a conservation-development perspective, the forest watersheds were classified into nine different types, and the characteristics were identified by each type. It is judged that the factors and clusters drawn as a result of the research accurately reflect the present conditions of Gyeonggi-do, and the nine types of forest watersheds have clear characteristics according to each type, which are judged to be utilized in forest management in the future.

• Korean Journal of Plant Resources
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• v.21 no.4
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• pp.299-303
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• 2008

Two-year-old seedlings of Ilex rotunda were grown under control (full sunlight) and three different shading condition. Those conditions were full sunlight (PPFD 1600${\mu}mol\;m^{-2}\;s^{-1}$), 30% (PPFD 400${\mu}mol\;m^{-2}\;s^{-1}$), 50% (PPFD 250${\mu}mol\;m^{-2}\;s^{-1}$) and 70% treatment (PPFD 100${\mu}mol\;m^{-2}\;s^{-1}$). Total chlorophyll contents were inverse proportion to light intensity. Seedlings under full sunlight showed the highest photosynthetic activity such as photosynthetic rate, intercellular $CO_2$ concentration and water use efficiency. Photosynthetic activity trend was increased at the higher light intensity than the lower treatment over PPFD 500${\mu}mol\;m^{-2}\;s^{-1}$. Especially, seedlings under 70% treatment showed the worst photosynthetic activity at high light intensity. That result was regular for adapted plant in low intensity environment. Leaf area was also inverse proportion to light intensity, while dry weight per leaf area was shown the opposite trend.

• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.107-117
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• 2024

This study investigated temporal changes in forest physical variables and their effects on thermal comfort and physiological and psychological responses. Environmental factors (air temperature, mean radiant temperature, wind speed, and relative humidity), the predicted mean vote (PMV), and the predicted percentage of dissatisfied (PPD) visitors were continuously measured between 9:00 AM and 6:00 PM. We assessed the physiological and psychological responses (heart rate variability, heart rate, oral temperature, blood pressure, pulse rate, thermal sensation vote, comfort sensation vote, and subjective feelings) of 30 male university students (average age: 21.7±1.9 years), who closed their eyes and relaxed for 5 minutes every hour. Examination of correlations between environmental factors and physiological responses showed that ① the mean radiant temperature, wind speed, and relative humidity significantly changed with time; ② PMV and PPD also showed significant changes over time, and the thermal sensation vote corresponded with PMV; however, the comfort sensation vote did not correspond with PPD; ③ Among the physiological responses, parasympathetic nerve activity, sympathetic nerve activity, heart rate, and diastolic blood pressure significantly varied with time, with parasympathetic nerve activity having the lowest value and sympathetic nerve activity the highest at the highest air temperature (2:00-4:00 PM); and ④ Air temperature, mean radiant temperature, and wind speed showed a negative correlation with parasympathetic nerve activity and a positive correlation with sympathetic nerve activity. These findings indicate that the relaxation effects of the forest environment depend on what time of day people are exposed to it, and the changes occurring in forest environmental factors over time modulate these effects.