• Journal of agriculture & life science
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• v.50 no.1
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• pp.73-81
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• 2016

The objectives of this study were to determine the effects of thinning intensity on the changes of vegetation structure in Japanese Evergreen Oak(Quercus acuta Thunb.) stands in Wando-arboretum. The flora were composed of 24 families, 33 genera, and 36species in thinned sites. The dominant layer of control site showed higher number of plant species than that of treatment sites. On the while, the sub-dominant layer, shrub layer, and herbaceous layer treatment sites showed higher number of plant species than control site. According to the analysis of importance value, Q. acuta in the dominant layer, Q. acuta and Camellia japonica in sub-dominant layer, and Camellia japonica in shrub layer showed the highest importance values, respectively. The importance value of Trachelospermum asiaticum was the highest in the herbaceous layer. According to the results, species diversity was higher in descending order of heavy thinning, light thinning, and control. This result could be explained by increased light transmissions from higher thinning intensity than in other treatments. In this context, the results of this study may be useful for selecting appropriate tending methods in terms of forest management and biodiversity conservation.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.175-181
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• 2014

This study was conducted to evaluate stand density-specific and generalized allometric equations, and biomass expansion factors (BEFs) for two stand densities (high density of 47-year-old: $667tree{\cdot}ha^{-1}$; low density of 49-year-old: $267tree{\cdot}ha^{-1}$) of Cryptomeria japonica plantations in Namhae-gun, located in the southern Korea. Biomass in each tree component, i.e. foliage, branch, and stem, was quantified by destructive tree harvesting. Allometric regression equations of each tree component were significant (P<0.05) with diameter at breast height (DBH) accounting for 80-96% of the variation except for branch biomass in high density or foliage and cone biomass in low density. Generalized allometric equations can be used to estimate the biomass of C. japonica plantations because the slopes of allometric equations were not significantly different by the stand density. The biomass expansion factors (BEFs) were significantly lower in the high stand density (1.33) than in the low stand density (1.50). The results indicate that BEFs were affected by different stand density, while allometric equations were little related to the stand density.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.3
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• pp.102-106
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• 2008

This study was carried out to evaluate the relationships between stand attributes and litterfall amounts in a 28-year old Quercus acutissima stand. Eighteen sampling plots of $20m{\times}20m$ were chosen and litterfall was collected from May 2005 to December 2006. There was no correlation between stand attributes(tree density, mean diameter at breast height, mean height, basal area) and litterfall amounts except for flower and miscellaneous litter for the study period. There were no significant relationships between leaf litter and basal area(r=0.02, 0.05; P=0.93, 0.83) and between leaf litter and tree density(r=-0.10, 0.05; P=0.85, 0.69). Also, leaf litter was affected neither by mean diameter at breast height(r=-0.08, 0.30; P=0.73, 0.22) nor by mean height(r=-0.24, 0.09; P=0.34, 0.70). Other litter amounts such as bark, branch, and acorn showed no relationships with the stand attributes (P>0.05). The lack of significant relationships between litterfall amounts and stand attributes could be due to the closed canopy with a complete crown cover in this mature oak stand.

• Journal of computational fluids engineering
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• v.20 no.2
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• pp.52-60
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• 2015

The objective of this research lies in the effect of installation parameters influencing on the wind proof performance of the coastal forest for damage prevention. The dissipation ratio of incident wind power is developed as an assessment index to make a lumped parameter study possible. From the real field data of East, West, and South Sea bounded on the Korean peninsula, single and double storied forests were modeled in three-dimensional shape with computer aided design, and so was done the artificial structures such as wind break, sand accumulating fence, and sand dune, etc With a commercial code ANSYS-CFX, the computational result from the comparison of dissipation ratio between single and double storied forest shows the effect of composition, and also the installation effect is investigated for artificial structures with optimal dimension of distance.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.4
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• pp.372-376
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• 2006

Ferulic acid is a phenolic compound that serves as a major biosynthetic precursor of vanillin in higher plants. We investigated the ability of the 3 commercial enzymes - Ultraflo L, Viscozyme L, and ${\alpha}-Amylase$ - to induce the release ferulic acid from the Ipomoea batatas L. (sweet potato) stem. The rate of release for ferulic acid was optimal when Ultraflo L (1.0%) was used compared with the other enzymes, whereas Viscozyme L was most effective for the release of vanillic acid and vanillin. Thus, these enzymes may be useful for the large-scale production of ferulic acid and other phenolic compounds from sweet potato stem.

• Journal of Korean Society of Forest Science
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• v.94 no.5 s.162
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• pp.334-337
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• 2005

Pine wood nematode isolates from Haman, Gyoungsangnam-do were cryopreserved with three different cryoprotectants (glycerol, ethylene glycol and dimethylsulfoxide), Nematode Growth medium (NGM) and M 9 buffer solution, respectively, and then survival rate, reproduction ability, and pathogenicity of stored nematodes were compared. Survival rates of juvenile was excellent in 15% glycerol solution as $72{\pm}5.3%$. The survival ability of nematodes at juvenile stage was more efficient than that of nematodes at adult stage. Pre-incubation treatment at $4^{\circ}C$ before storing in liquid nitrogen didn't affect the survival ability of pine wood nematode. When the reproduction ability of nematodes was confirmed on Botrytis cinerea agar plates at $28^{\circ}C$ incubator, there was no difference between cryopreserved and non-cryopreserved. Pathogenic ability of cryopreserved nematodes was also evaluated and confirmed by artificially inoculating them on 2-year old red pine seedlings.

• Journal of Korean Society of Rural Planning
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• v.26 no.2
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• pp.1-12
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• 2020

This study aimed to define characteristics of mountain village landscapes perceived by locals to sustainably preserve and manage mountain village landscapes. We selected landscape resources of mountain villages by reviewing previous studies and conducting field surveys and surveyed mountain villages' locals to investigate the characteristics of their perceptions of the mountain village landscapes. The surveys were conducted from March to October 2019, in the form of 1:1 questionnaire survey. In consequence, highly reliable 150 responses were analyzed. IPA method(Revised Importance-Performance Analysis) was used in the analysis. It is found that, in landscapes, the first quadrant is 'Cultivated land, Forest', the second quadrant is 'Coastal, Forestry and Agriculture Facility', the third quadrant is 'Forest Service·Profitable Facility, Settlement, History and Culture', and the fourth quadrant is 'Riparian, Street'. In conclusion, locals of mountain villages are perceiving the mountain village landscapes based on their livelihoods and daily lives, and the mountain village landscapes are closely related to their lives. The results of this study are expected to be utilized as fundamental resources in establishing policies regarding sustainable conservation and management of mountain village landscapes which led by locals.

• Korean Journal of Plant Resources
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• v.36 no.3
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• pp.191-197
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• 2023

Autophagy contributes to enhancing the immune system (innate and adaptive immune system) against foreign pathogens. Autophagy of macrophages is used as a major indicator for developing vaccine adjuvants to increase the adaptive immune response. In this study, HSL increased p62/SQSTM1 expression. Inhibition of TLR4, p38, JNK, and NF-κB blocked HSL-mediated increase of p62/SQSTM1. HSL activated p38, JNK, and NF-κB signaling, but HSL-mediated activation of p38, JNK, and NF-κB signaling was reversed by TLR4 inhibition. In addition, HSL increased Nrf2 expression, but HSL-mediated Nrf2 expression did not occur in the inhibition of TLR4, p38, JNK, and NF-κB. Taken together, it is believed that HSL-mediated autophagy may be dependent on activating Nrf2 expression via TLR4-dependent activation of p38, JNK, and NF-κB in macrophages.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.5
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• pp.43-49
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• 2014

Fairy Pittas use the forest around the valley and Gotjawal as breeding places. This survey was conducted to investigate the characteristic of earthworms, specifically its population density, body size around the breeding site in Gotjawal and the forest around the valley areas from the middle of July to the end of July 2013. A total of 405 individual earthworms were collected in the 100 small established quadrats, in which 315 were found in Gotjawal and 90 were found in the forest around the valley area. The density of earthworms in Gotjawal was significantly higher compared to that forest around the valley area. It was also observed that the body size of earthworms was significantly different between Gotjawal and the forest around the valley area. Proportion of number of individuals which are larger than 7cm in body size was 43%(n=135) in Gotjawal and 84%(n=76) in the forest around the valley area, respectively. Soil area was not important factor to the density of earthworms. We suggest that Gotjawal can be considered as a suitable breeding site for Fairy Pitta because of the richness of its primary food in this area.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.202-210
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• 2020

This study investigated the optimal levels of stand density control considering the stability of Larix kaempferi stands. A stand density management diagram was developed from 259 sample plots. Based on these data, we determined an optimal level of the stand density control by identifying the relationship between the relative yield index (Ry) and height-to-diameter ratio. The estimated r-square (R²) of the stand density management diagram is 0.600. The analysis of the relationship between Ry and the slender tree incidence showed that when the stand density exceeded a certain threshold and the ratio of slender trees rapidly increased. The critical value of Ry was 0.63. The results of this study are expected to contribute to the establishment of stand management strategies that can reduce damage from natural causes, such as wind and snow, and to develop stand practice systems for the improved productivity of commercial forests.