• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.470-478
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• 2010

UV-protection skin whitening and immune activities several parts of Acer mono and Acer okamotoanum were investigated. The bark of both Acer mono and Acer okamotoanum had higher yields than other parts as 2.67% and 2.45%. The cytotoxicity of the extracts were lower than 21.64% against human skin cell(CCD-986sk) line in adding 1.0 mg/mL of the highest concentration. The bark extracts of Acer mono greatly reduced the expression of MMP-1 on UV-irradiated CCD-986sk cells down to as 30%. At 1.0 mg/mL of bark extration of Acer mono, $PGE_2$ expression was also significantly decreased. Generally, the bark extracts of Acer mono and Acer okamotoanum had higher activity than other parts, but, interestingly, wood extract of Acer okamotoanum showed strong inhibition effect on melanin production by Clone-M3 cells as 79.25%. From these results, we could conclude that the bark extract from Acer mono and Acer okamotoanum had skin-whitening activity as well immune enhancement activity.

• Journal of Forest and Environmental Science
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• v.33 no.4
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• pp.342-347
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• 2017

Since the first report of the oak wilt disease at 2004 in Korea, the disease distributed over Korean peninsula and are still giving severe damages. The management of oak wilt disease in Korea has mainly focused on the control of insect vector, Platypus koryoensis. Neverthless the effective method for evaluating the pathogenicity of the pathogen, Raffaelea quercus-mongolicae (Rqm), and for screening chemical or biological agents with strong inhibitory activity against the pathogen, is absolutely necessary, an reliable method is not available so far. This study was conducted to develop the effective method for evaluating the pathogenicity of Rqm in oak trees. The culture suspensions of Rqm were artificially injected to the saplings of Quercus acutissima by using ChemJet tree injector. Three months after treatments, the treated saplings were cut and dipped into 1% fuchsin acid solution. There were significant differences in non-conductive area (%), discoloration area (%) and vertical discoloration length between the pathogen-injected and distilled water-injected control treatments. These results indicated that the pathogen is the causal agent for the dysfunction of water conductive tissue, which will finally result in wilt symptom. Re-isolation of the pathogen and PCR detection using specific primers for the pathogen also confirmed the presence of Rqm in the sapwood chips of the pathogen-injected saplings. These observations would be greatly applied to other related researches for evaluating the pathogenicity of tree wilt pathogens and biocontrol efficacy of the selected antagonistic microorganisms, in case that the wilt symptom is not easily shown by artificial inoculation of the causal agent.

• Korean Journal of Pharmacognosy
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• v.48 no.1
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• pp.18-24
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• 2017

This study was conducted to determine the anti-inflammatory effect of essential oil extracted from the wood of Chamaecyparis obtusa Sieb. et Zucc. Endl. (Cupressaceae). The essential oil was extracted from the wood of C. obtusa by hydrodistillation method, and conducted the analysis on the chemical composition of the extracted C. obtusa wood oil through GC-MS. The major constituents of the oil were found to be: ${\alpha}-pinene$ (11.4%), cadinene (5.4%), ${\delta}-cadiene$ (9.0%), ${\tau}-muurolol$ (22.2%), ${\alpha}-cadinol$ (20.8%) etc. We attempted to identify the anti-inflammatory activities of the oil when it is injected in the lipopolysaccharide (LPS)-stimulated RBL-2H3 cells, along with its effects on the secretion of interleukin-4 (IL-4), interleukin-13 (IL-13), ${\beta}-hexosaminidase$. According to the cell viability analysis conducted by MTT assay, the oil in $10^{-7}{\sim}10^{-5}%$concentration showed no effect on the cell viability. After RBL-2H3 cells treated by LPS stimulation were exposed to $10^{-7}%$ concentration of C. obtusa wood oil, the expression levels of IL-4, IL-13 within the cell were observed to remarkably decrease. Also, it was attenuated the release of ${\beta}-hexosaminidase$ from mast cells to a significantly meaningful level. These results suggest that C. obtusa wood oil exerts the anti-inflammatory effect, by regulating the expression of inflammatory cytokines, which is a valuable feature to be highly utilized as the functional materials in the future.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.80-86
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• 1997

The objective of this study was to investigate how resistant poplar hybrid makes compensation to ozone stress. Growth, net assimilation rate and initial Rubisco activity were investigated. This study elucidates the physiological mechanisms associated with ozone sensitivity and resistance in 3 selected $F_2$ hybrids, a family originating from a cross between Populus trichocarpa${\times}$P. deltoides. Open-top chambers were used. Ozone concentrations varied from 90 to 115 ppb for 126 days, 6 to 9 hours in a day. This study tested the hypothesis that resistant poplar hybrid maintains the biomass production to ozone exposure via increased net assimilation rate and Rubisco activity. Growth, biomass, net assimilation rate and initial Rubisco activity were generally reduced by ozone treatment. In the tree parts, root under ozone stress was the most sensitive part. Reduced allocation of photosynthates to root growth might be due to increased respiratory demands for maintenance and repair of aboveground tissue damaged by ozone stress. Maintenance or increases remaining leaves in photosynthetic rates and Rubisco activity in resistant clone in response to ozone treatment were the results of biological compensation to ozone stress.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.84-92
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• 2008

Anatomical and physical characteristics of Pinus densiflora woods damaged by forest fire at Yangyang-gun, Kangwon-do were investigated in present study. Even though the bark was severly carbonized, no trace of carbonization in the xylem was found. The amount of resin exudation was different by the degree of fire damage. Green moisture content of sapwood in the damaged wood was lower than that in the sound wood, but vice versa in the heartwood. Green density of heartwood in the damaged wood was higher than that in the sound wood, but there was no significant difference in sapwood. Cambial activities were found stopped in the severely damaged wood but were identified in the lightly damaged wood. In safranine staining process, epithelial and ray parenchyma cell walls in the damaged woods showed darker hue than those in the sound wood. Granular substances were observed in the lumina of ray parenchyma and epithelial cells of the severely damaged wood. Relative crystallinity of the outermost growth ring in the severely damaged wood was slightly higher than that in the sound wood.

• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.696-702
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• 2009

Yellow poplar (Liriodendron tulipifera L.) is an insect-pollinated tree species with large, perfect flower, and its seed sets average only about 10 percent naturally. In its controlled pollination, pollination bags are usually taken to prevent unwanted pollination, but bagging is an expensive and time-consuming process. Therefore, this study was conducted to determine the need of pollination bag by estimating how much unintended pollination would occur when different cross methods were applied. Five different pollination methods were applied as follows: 1) natural open pollination (i.e. insect pollination) as a reference, 2) self-pollination; no removing reproductive organs with bagging, 3) open pollination; emasculated(removing sepal, petal and stamen) without bagging, 4) controlled pollination; emasculated with bagging and 5) controlled pollination; emasculated without bagging. Very low value of full seed rate (0.2%) was observed in method 3, it was suggested that removing stamen and petal restrict the activity of pollen vectors like bee. Difference in the full seed rate between method 4 and method 5 was not significant (27.9% versus 24.0%, respectively). Consequently, controlled pollination without bagging might be an alternative method for extensive breeding and mass production of seeds in yellow poplar.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.321-326
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• 2005

We investigated the effects of pollutants on two pine species (Pinus koraiensis and Pinus rigida) in an industrial region, using a physiological approach. We measured the growth and physiological parameters (photosynthetic activity and chemical contents) of the pine trees in relation to environmental pollutants. The concentrations of manganese (Mn), fluorine (F) and chlorine (CI) in needles of two pine species at the damaged site were significantly higher than those at the control site, and concentrations of essential elements (P) and chlorophyll in needles at the damaged site were significantly lower than at the control site. The light-saturated net photosynthesis $(P_{sat})$, apparent quantum yield $(\Phi)$, carboxylation efficiency (CE) of both pines at the damaged site were significantly lower than those at the control site. The length of shoots and survivorship of needles of two pines at the damaged site were significantly lower than those at the control site. Especially, at damaged site, growth of shoots and needle longevity of P. koraiensis are larger than those of P. rigida.

• Research in Plant Disease
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• v.20 no.4
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• pp.295-298
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• 2014

Oak wilt caused by Raffaelea quercus-mongolicae was first noticed in South Korea in 2004 and, ever since, its distribution and damage have been increasing. To screen a fungicide effective for oak wilt control by tree injection, laboratory and field experiments were conducted. Ten fungicides and one antibiotic were examined in vivo for their effectiveness in restricting the growth of R. quercus-mongolicae and R. quercivora (Japanese oak wilt pathogen) isolates. To the Korean isolates of R. quercus-mongolicae, chlorothalonil showed the highest fungicidal effects, followed by benomyl and propiconazole. To the Japanese one, propiconazole was highest in the fungicidal effectiveness, followed by benomyl and bitertanol. Propiconazole was selected for field-testing of its control efficacy because it showed good fungicidal effects in vitro and systemic activity. The control efficacy in the field was 87.5% in the first year of injection and 66.7% in the second year, indicating the fungicidal effects last at least over one year.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.354-359
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• 2009

Land cover types of Hustai National Park (HNP) in Mongolia, a hotspot area with rare species, were classified and their temporal changes were evaluated using Landsat MSS TM/ETM data between 1994 and 2000. Maximum likelihood classification analysis showed an overall accuracy of 88.0% and 85.0% for the 1994 and 2000 images, respectively. Kappa coefficients associated with the classification were resulted to 0.85 for 1994 and 0.82 for 2000 image. Land cover types revealed significant temporal changes in the classification maps between 1994 and 2000. The area has increased considerably by $166.5km^2$ for mountain steppe. By contrast, agricultural areas and degraded areas affected by human being activity were decreased by $46.1km^2$ and $194.8km^2$ over the six year span, respectively. These areas were replaced by mountain steppe area. Specifically, forest area was noticeably fragmented, accompanied by the decrease of $\sim400$ ha. The forest area revealed a pattern with systematic gain and loss associated with the specific phenomenon called as forest free-south slope. We discussed the potential environmental conditions responsible for the systematic pattern and addressed other biological impacts by outbreaks of forest pests and ungulates.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.748-757
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• 2019

This study was intended to investigate the effects of forest therapy programs using school forest on the emotional stability and positive thinking of university students. The subjects were divided into an experimental group and a controlled group, and the number of subjects in each group was 35 and 25, respectively. The forest therapy program was conducted once a week from 4 September to 12 December in 2018 for a total of 8 sessions, and each session lasted two hours (120 minutes). The subjects were examined in the emotional state and positive thinking before and after the forest therapy program. To determine the difference in emotional stability and positive thinking before and after the program, I conducted a paired t-test and analyzed the data with the SPSS 21.0 program. The results indicated that students who participated in the program showed a significant increase in the stabilize emotional state and positive thinking. This study shows that forest therapy programs using school forests have an effect on students' emotions and positive thinking. Thus, it is necessary to promote the forest therapy program as an alternative activity for the treatment and prevention of mental health of university students.