• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.242-250
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• 2010

The aim of this study was to investigate the terpenoids of Total Volatile Organic Compounds (VOCs) released during drying of Cryptomeria japonica using the thermal extractor (TE). Considering the drying process of C. japonica, temperatures of TE were set at $27^{\circ}C$, $60^{\circ}C$, $80^{\circ}C$, $100^{\circ}C$, and $120^{\circ}C$, respectively. As the result, the emission factors of VOCs and terpenoids were increased as temperature increased. The amount of terpenoids included in VOCs emission factors were 87.5%, 81.6%, 83.6%, 90.1%, and 97.3% depending on above temperatures, respectively. Especially at$100^{\circ}C$ and $120^{\circ}C$, the amount of terpenoids were measured more than 90%. ${\delta}$-cadinene was the highest yield at each temperature and 32 types of terpenoids were collected. Emitted terpenoids were classified into the sesquiterpene group which consists of 15 carbon sources. These 32 sesquiterpenes were used for determining the useful bioactivity such as antifungal activity by the agar dilution. As the result, they showed the antifungal activity against Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum gypseum. The 5,000 ppm concentration of terpenoids showed a strong activity with 100% against the 3 fungi. At the 1,000 ppm concentration of terpenoids, the antifungal activities against three fungi were 95.2%, 98.7%, and 97.3%, and their activities were a little inhibited at 100 ppm concentration.

• Applied Biological Chemistry
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• v.44 no.4
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• pp.269-272
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• 2001

This study was carried out to investigate the antifungal activities of the extracts from various parts of three pinus species, P. densiflora, P. rigida and P. koraiensis to pathogenic fungus Collectotrichum gloeosporioides. The EtOAc fraction from the bark of P. koraiensis stem and root showed 98.8 and 100% of activity, respectively to the fungus. Median effective doses $(ED_{50})$ of above two fractions were 469 and 588 ${\mu}g/ml$, respectively in the bioassay with the fungus. $ED_{50}$ of the EtOAc fraction from the bark of P. koraiensis stem against Alternaria brassicicola and Fusarium oxysporum was 533 and 2,277 ${\mu}g/ml$, respectively. This means that the fraction was more sensitive to the C. gloeosporioides and A. brassicicola than the fungus F. oxysporum. The EtOAc fraction from the leaves of P. densiflord showed 39.6% of activity to C. gloeosporioides, but all the fractions from the leaves of two species showed no activity. The active compounds in the bark of P. koraiensis stem and root are being identified.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.767-773
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• 2001

We investigated the impacts of the fairy-ring of Tricholoma matsutake on the dynamics of soil microflora and soil enzyme activities by grouping the soils around the fairy-ring of T. matsutake into four regions. The regions were grouped as 'zone of decayed mycorrhizae', 'zone of mycorrhizae for fruiting', 'zone of physiologically active mycorrhizae' and 'zone free from mycorrhizal infection'. Soil fungi and actinomycetes were quite little at the soils around the fairy-ring of T. matsutake compared to those of general forest soils, and there were significant differences among the four regions. The soils with the mycelial cluster of T. matsutake showed about one third of microbial population compared to those in the zone free from mycorrhizal infection, which indicated that T. matsutake took a dominant position within the fairy-ring of the fungus. We could manifest that T. matsutake showed a distinctive characteristics of mycorrhizal fungus since the activities of dehydrogenase were significantly different between the zone of physiologically active mycorrhizae and the zone free from mycorrhizal infection. The dehydrogenase activity was the highest at the early season of fruiting around the fairy-ring of T. matsutake, while the acid-phosphatase activity increased from March to June followed by a slight decrease on August and peaked on October. This phenomenon made us infer that the vitality of T. matsutake be sustained after fruiting.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.4
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• pp.21-30
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• 2007

This study aims to understand the characteristics of dangsan forests and rural community forests (RCF), and seek for a landscape management scheme. Dangsan forests and RCF have been maintained by local residents since hundreds of years ago. However, many of them have been disturbed. The case sites were derived from the twenty villages previous investigated where dangsan forests and RCF's remainrd. The two sites were remodelled to restore what have been degraded. Hanbam village has maintained its dangsan forest with good management practices, whereas the dangsan forest and RCF of Goiran village showed relatively poor management. The size of dangsan forest at hanbam village was 13,784$m^2$, and major tree species was Pinus densiflora. In total, 151 trees with more than 30cm in DBH were standing on the site. As a cultural activity, the dangsan festival have been held in January $5^{th}$ by lunar calendar to the 2005 at the Jindongdan, a dangsan tree made of stone. The RCF of Hanbam village has disappeared due to the event of landslide in 1930, which needs to be restored. Goiran village has a dangsan forest and a RCF. The forests in Goiran village revealed many problems due to bad management practice. The prototype of the dangsan forest was deteriorated by introduced Prunus serrulata and the facilities for physical training. A systematic management scheme for dangsan forests and RCF's should be established with a close partnership among local residents, experts, and local government.

• The Korean Journal of Pesticide Science
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• v.5 no.2
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• pp.62-66
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• 2001

The thirteen commercial insecticides to Lycoriella mali were investigated on their insecticidal activities and mycelial growth of two Letinula edodes strains. For the adults, insecticides showing over 95% insecticidal activity were chlorpyrifos-methyl, fenthion, fenitrothion, benfuracarb, furathiocarb and deltamethrin. For tile larvae, diflubenzuron and cyromazine showed over 90% insecticidal activity. Fenthion, benfuracarb, furathiocarb, deltamethrin, diflubenzuron and cyromazine did not affect the mycelial growth of L. edodes strain, in Imhyup 1 variety. And deltamethrin, diflubenzuron and cyromazine did not affect that in Sanlim-5. Insecticides showing over 80% residual effect for 14 days were benfuracarb to the adults and diflubenzuron and cyromazine to the larvae. Control effect of furathiocarb, fenthion, benfuracarb, deltamethrin, diflubenzuron and cyromazine against larvae of Lycoriella mali showed 90% ten days after application under sawdust cultivation. Among them, benfuracarb, fenthion and furathiocarb revealed excellent control effect against adults. These results indicate that benfuracarb, fenthion, and furathiocarb can be used for the control of Lycoriella mali in the field. However, further studies are needed on the effect of insecticides treatment oil fruit-body yield and chemical residue in the mushroom tissues.

• Journal of Ecology and Environment
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• v.34 no.2
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• pp.203-214
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• 2011

The objectives of this research were to predict land-use/land-cover change at the Sakaerat Environmental Research Station (SERS) and to analyze its consequences on the distribution for Black-crested Bulbul (Pycnonotus melanicterus), which is a popular species for bird-watching activity. The Dyna-CLUE model was used to determine land-use allocation between 2008 and 2020 under two scenarios. Trend scenario was a continuation of recent land-use change (2002-2008), while the integrated land-use management scenario aimed to protect 45% of study area under intact forest, rehabilitated forest and reforestation for renewable energy. The maximum entropy model (Maxent), Geographic Information System (GIS) and FRAGSTATS package were used to predict bird occurrence and assess landscape fragmentation indices, respectively. The results revealed that parts of secondary growth, agriculture areas and dry dipterocarp forest close to road networks would be converted to other land use classes, especially eucalyptus plantation. Distance to dry evergreen forest, distance to secondary growth and distance to road were important factors for Black-crested Bulbul distribution because this species prefers to inhabit ecotones between dense forest and open woodland. The predicted for occurrence of Black-crested Bulbul in 2008 covers an area of 3,802 ha and relatively reduces to 3,342 ha in 2020 for trend scenario and to 3,627 ha for integrated-land use management scenario. However, intact habitats would be severely fragmented, which can be noticed by total habitat area, largest patch index and total core area indices, especially under the trend scenario. These consequences are likely to diminish the recreation and education values of the SERS to the public.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.255-262
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• 2021

This study examined the effect of rope play through forest experience on children's self-confidence. Empirical analysis through the experimental design was carried out on an experimental group of 15 (seven male and eight female children) and a control group of 15 (nine male and six female children). Analysis of covariance (ANCOVA) for the effect between the experimental and control groups after the experimental treatment showed that the mean of the experimental group was significantly higher than that of the control group (F=357.350, p<.001). Rope play through forest experience has a statistically significant effect on the children's self-confidence. Consequently, rope play through forest experience between peers is a beneficial experience that helps improve children's self-confidence. Furthermore, it is a positive play activity to help them with a passive character boost to their self-confidence through cooperation between peers.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.33-40
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• 2013

Pyrifluquinazon is known to act as a feeding inhibitor in several insect species. In this study, we investigated the effect of pyrifluquinazon on the whiteflies, Trialeurodes vaporariorum and Bemisia tabaci. Pyrifluquinazon showed high insecticidal activity (> 90%) against adult T. vaporariorum and B. tabaci at 12.5 ppm to 50 ppm. However, there was no effect on eggs and nymphs of both species. Pyrifluquinazon showed low insecticidal activity in root and foliar uptake. Control efficacy of pyrifluquinazon was above 90% at 5 days after treatment. In order to investigate the behavioral response of the whiteflies initiated by application of pyrifluquinazon, we tested the contact toxicity and ingestion toxicity. After 1 h of contact, whitefly drop, wing convulsion, and paralysis were observed. Similar phenomenon of whitefly population was observed in test of ingestion toxicity after 3 h. In the choice test, pyrifluquinazon showed repellent activity against both species. These results suggest that pyrifluquinazon cause behavioral disorder rather than direct inhibition of feeding.

• 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.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.169-177
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• 2013

We investigated the effect of extracts($50{\mu}g/mL$) from 31 folk plants in Ulleung Island on nitric oxide(NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Actinidia arguta(leaf, twig), Hovenia dulcis(leaf), Camellia japonica(leaf, twig), Sambucus sieboldiana var. pendula(leaf, twig) and Fallopia sachalinensis(root) showed significant NO inhibition activity(42%~88% NO inhibition rate). Of them, we selected 3 samples(A. arguta, H. dulcis and C. japonica) showing more than 50% NO inhibition activity and little effect on cell viability. We found that the extracts suppressed the NO and prostaglandin $E_2(PGE_2)$ produced by LPS-activated RAW264.7 cells in dose-dependent manners.