• Journal of Korean Society of Forest Science
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• v.82 no.2
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• pp.188-194
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• 1993

A natural Quercus variabilis forest and a Populus alba${\times}$P. glandulosa plantation in Mt. Mohu area were studied to investigate aboveground biomass and net production. A $20m{\times}30m$ quadrat was set up in each stand, and 10 sample trees each of Quercus variabilis and Populus alba ${\times}$ P. glandulosa were cut for dimension analysis. There was little difference in accuracy among three biomass regression models of logWt=A+BlogD, $logWt=A+BlogD^2H$, and logWt=A+BlogD+ClogH, where Wt. D, and H were dry weight, DBH, and height, respectively. Aboveground total biomass of Quercus variabilis stand was 31,275kg/ha, and that of Populus alba ${\times}$ P. glandulosa was 55,581kg/ha. In both of Quercus variabilis stand and Populus alba ${\times}$ P. glandulosa stand, the proportion of each tree component to abovegound total biomass was high in order of stem wood, branches, stem bark, and leaves. Quercus variabilis stand was higher in the proportion of stem bark, branches and leaves than Populus alba ${\times}$ P. glandulosa stand, while the former was lower in that of stem wood than the latter. Aboveground total net production of Quercus variabilis stand was 4,267kg/ha/yr., and that of Populus alba ${\times}$ P. glandulosa stand was 3,903kg/ha/yr. The proportion of each tree component to aboveground total net production of Quercus variabilis stand was high in order of leaves, stem wood, branches, and stem bark. That of Populus alba ${\times}$ P. glandulosa stand was high in order of stem wood, leaves, branches, and stem bark. Net assimilation rate and efficiency of leaf to produce stem of Quercus variabilis stand were 2.121 and 0.840, respectively. Those of Populus alba ${\times}$ P. glandulosa stand were 3.376 and 2.085, respectively. Though Populus alba${\times}$P. glandulosa stand was lower in aboveground total net production than Quercus variabilis stand, the former was higher in aboveground total biomass than the latter. The reason was that Populus alba${\times}$P. glandulosa stand was higher in net production of stem wood of accumulation organs than Quercus variablis stand.

• Journal of Korea Water Resources Association
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• v.54 no.6
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• pp.407-418
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• 2021

In this study, the two-dimensional flow model, Nays2DH, and driftwood dynamics model were combined to analyze the flow and driftwood behavior depending on the characteristics of the inflow of driftwood and the length of the driftwood stem. In particular, the Dashpot-spring model was added to the driftwood dynamics model to simulate the collision motion of the driftwood, and the wood jam characteristics by the collision of the driftwood were compared. As a result of the simulation, the pass rate of the obstacle section, the travel distance of wood jam, and the mean position of the wood pieces were respondent sensitively by the length of the driftwood stem, but the cohort size of the driftwood supply was insignificant excepting for the pass rate. Through this study, we could understand the interaction between hydraulic structures and driftwood, and through this, it is believed that it will be helpful in establishing a durable maintenance plan for hydraulic structures by predicting the transport and jam formation phenomena of driftwood in advance.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.484-490
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• 2013

This study was conducted to develop a simulation model for estimating the amount of such products as round wood, dimension lumber and the residual wood biomass produced by processing the individual trees of Larix kaempferi. In the model, the stem volume is assessed using the taper equations of the species to estimate the stem forms. Then, the model simulates the conversion processes of logs to round wood or lumber and assesses the maximum amount of the wood products by the lumber dimensions or round wood size. Also the model provides information on the amount of residuals for kerf and slabs produced on the conversion processes for sawn timber or round wood. According to the results of an application of the model to a L. kaempferi process, the trees greater than 12 cm of DBH can be converted to logs for lumber or round wood production. For the trees, of which DBH is available for log conversion, the maximum amount of final products by dimensions were analyzed. In this analysis, production of the bigger dimension lumber was assumed to be preferred to that of the smaller or round wood. This model can be used for assesment of forest economic value through estimation of merchantable volume for the trees, and assessment of mill residues which has the potential to provide significant amount of feedstock for bioenergy production as well.

• Journal of Korean Society of Forest Science
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• v.16 no.1
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• pp.33-62
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• 1972

Pitch pine (Pinus rigida Miller) in Korea has become one of the major silvicultural species for many years since it was introduced from the United States of America in 1907. To attain the more rational wood utilization basical researches on wood properties are primarily needed, since large scale of timber production from Pitch Pine trees has now been accomplishing in the forested areast hroughout the country. Under the circumustances, this experiment was carried out to study the wood anatomical, physical and mechanical properties of Pitch Pine grown in the country. Materials used in this study had been prepared by cutting the selected pitch pine trees from the Seoul National University Forests located in Suwon. To obtain and compare the anatomical and physical properties of the different parts of tree such as stem, branch, top and rootwood, this study had been divided into two categories (anatomical and physical). For the anatomical study macroscopical and microscopical features such as annual ring, intercellular cannal, ray, tracheid, ray trachid, ray parenchyma cell and pit etc. were observed and measured by the different parts (stem, branch, root and topwood) of tree. For the physical and mechanical properties the moisture content of geen wood, wood specific gravity, shrinkage, compression parallel to the grain, tension parallel and perpendicular to the grain, radial and tangential shear, bending, cleavage and hardness wree tested. According to the results this study may be concluded as follows: 1. The most important comparable features in general properties of wood among the different parts of tree were distinctness and width of annual ring, transition from spring to summerwood, wood color, odor and grain etc. In microscopical features the sizes of structural elements of wood were comparable features among the parts of tree. Among their features, length, width and thickness of tracheids, resin ducts and ray structures were most important. 2. In microscopical features among the different parts of tree stem and topwood were shown simillar reults in tissues. However in rootwood compared with other parts on the tangential surface distinctly larger ray structures were observed and measured. The maximum size of unseriate ray was attained to 27 cell ($550{\mu}$) height in length and 35 microns in width. Fusiform rays were formed occasionally the connected ray which contain one or several horizontal cannals. Branchwood was shown the same features like stemwood but the measured values were very low in comparing with other parts of tree. 3. Trachid length measured among the different parts of tree were shown largest in stem and shortest in branchwood. In comparing the tracheid length among the parts the differences were not shown only between stem and rootwood, but shown between all other parts of tree. Trachid diameters were shown widest in rootwood and narrowest in branchwood, and the differences among the different parts were not realized. Wall thickness were shown largest value in rootwood and smallest in branchwood, and the differences were shown between root and top or branchwood, and between stem and branch or top wood, but not shown between other parts of tree. 4. Moisture contents of green wood were shown highest in topwood and lowest in heartwood of stem. The differences among the different parts were recognized between top or heartwood and other parts of tree, but not between root and branchwood or root and sapwood. 5. Wood specific gravities were shown highest in stem and next order root and branchwood, but lowest in topwood. The differences were shown clearly between stemwood and other parts of tree, but not root and branchwood. However the significant difference is realized as most lowest value in topwood. 6. In compression strength parallel to the grain compared among the different parts of tree at the 14 percent of moisture content, highest strength was appeared in stem, next order branch and rootwood, but lowest in topwood. 7. In bending strength compared among the different parts of tree at the 14 percent of moisture content clearly highest strength was shown in branchwood, next order stem and root, but lowest in topwood. Though the branchwood has lower specific gravity than stemwood it was shown clearly high bending strength.

• Journal of Korea Foresty Energy
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• v.18 no.1
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• pp.1-5
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• 1999

Variations in the wood quality were analyzed to utilize Korean pine (Pinus koraiensis S. et Z.) efficiently and to develop suitable use, depending on the stem location. Variations in the tracheid length and width, microfibril angle, compression strength were measured at the heights of 0.3, 1.3, 2.3, and 5.3m in the longitudinal direction of the 20m pine and they were analyzed by Duncan`s multiple range test. Variations in the tracheid length, width and compression strength did not show significant difference, whereas those in the microfibril angle showed significant difference. However, the microfibril angle did not vary with the height of trees, showing inconsistent pattern in change.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1114-1118
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• 2006

(+)-Eudesmin [4,8-bis(3,4-dimethoxyphenyl)-3,7 -dioxabicyclo[3.3.0]octane] was isolated from the stem bark of Magnolia kobus DC. var. borealis Sarg. and found to have neuritogenic activity. $50\;{\mu}M$ (+)-eudesmin induced neurite outgrowth and enhanced nerve growth factor (NGF)-mediated neurite outgrowth from PC12 cells. At this concentration, (+)-eudesmin also enhanced NGF-induced neurite-bearing activity and this activity was partially blocked by various protein kinase inhibitors. These included PD98059, a mitogen-activated protein kinase (MAPK) kinase inhibitor. GF109203X, a protein kinase C (PKC) inhibitor and H89, a protein kinase A (PKA) inhibitor. These results suggest that (+)-eudesmin can induce neurite outgrowth from PC12 cells by stimulating up-stream MAPK, PKC and PKA pathways.

• Journal of the Korean Wood Science and Technology
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• v.26 no.2
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• pp.45-50
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• 1998

Tracheid length, microfibril angle, and compression strength were examined in south and north sides of Pinus koraiensis. The sample tree was 57 years old and had been planted in central Korea. Tracheid length on the south side of the tree ranged from 2.87 to 3.40mm and on the north ranged from 3.60 to 3.53mm and mean values were 3.15 mm for the south and 3.26mm for the north. Tracheid length was 0.11 mm longer on the north side than on the south. Microfibril angle on the south side ranged from $12.6^{\circ}$ to $20.3^{\circ}$ and that on the north from $6.8^{\circ}$ to $13.5^{\circ}$; mean values were $16.6^{\circ}$ on the south side and $9.6^{\circ}$ on the north. Microfibril angle was $7.0^{\circ}$ greater on the south side than on the north side. For compression strength on the south and north sides, significant difference at the 95% level was found only at l.3m above the ground level of the sample tree; for compression limit stress, significant difference at this level was found at 1.3 and 5.3m above the ground level. However, compression strength and compression limit stress were greater on the north side than on the south side.

• Korean Journal of Organic Agriculture
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• v.8 no.1
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• pp.89-99
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• 1999

To do mass multiplication of plug seedlings in potatoes, apical stem cuttings originated from virus-free microtubers were cut to one-two internodes and transplanted into the plug-tray. After 10days, we applied Chitosan and Wood Extraction on rooting and tuber formation of plug seedlings. To improve field adaptability of plug seedlings, rooted cuttings with a height of 20cm after 20days of cutting were transplanted ito the fields, We applied 500~2000ppm Chitosan on growth characteristics and tuber formation of that. The above and underground growths, such as plant height and number of leaves were significantly more vigorous after treatment with 500~1,000ppm Chitosan and 2,000ppm Wood Extraction, the spray treatment was carried out five times at intervals of four days after ten days of transplanting. T-N, K, P, Mg and Na, were higher as the concentrations of chitosan and Wood Extraction were higher. The growth and tuber yield in plug seedlings planting plot and seed potatoes planting plot were effectively highter as foliar application of Chitosan(500~2,000ppm) was done after planting the plot. T-N content in leaves and tuber was higher as the concentration of Chitosan was high. A similar tendency was shown in K, P and Mg. In the small tuber(under 30g), the number of tubers and tuber yield were relatively increased in the seed potatoes planting plot, but the large tubers(over 80g) yield was higher in the plug seedlings planting plot, and in order to increase tuber yield in plug seedlings it was necessary to add plant density to the field.

• Journal of the Korean Wood Science and Technology
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• v.52 no.2
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• pp.134-144
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• 2024

This study aimed to analyze the anti-termite properties of tamanu (Calophyllum inophyllum L.) stem bark extracts against subterranean termites, specifically, Coptotermes curvignathus. The bark powder of C. inophyllum was extracted using different solvents, such as n-hexane, ethyl acetate, and methanol, using the maceration method. Anti-termite testing was performed using two paper disc methods: no- and two-choice tests. Whatman test paper was dripped with the extract solutions at concentrations of 4%, 6%, 8%, and 10% (w/v). Subsequently, the treated paper disc was placed into an acrylic tube, and the subterranean termite was added. The parameters utilized in the test included termite mortality and the weight loss of the test paper. The results revealed that the total extract yield of C. inophyllum stem bark was 30.24%. Furthermore, the extractive substances from C. inophyllum bark exhibited anti-termite activity. The most favorable outcomes were obtained with the n-hexane and ethyl acetate extracts at a concentration of 10%. The termite mortality and weight loss of the test paper were respectively 66% and 5.67% for the n-hexane extract and 66.67% and 6.19% for the ethyl acetate extract. In addition, the n-hexane extract contained friedelan-3-one, while the ethyl acetate extract contained 1,2-benzene dicarboxylic acid, dinonyl ester, and friedelan-3-one. The results suggested that these compounds are responsible for the observed anti-termite activity.

• Journal of the Korean Wood Science and Technology
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• v.21 no.3
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• pp.37-44
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• 1993

The collapse of four domestic Fagaceae species was observed in relation with their moisture content(MC), basic density, P (Percent of moisture content saturation of the wood) and Q (Percent of cell cavity volume containing water) and the variation of collapse phenomenon in the cross section of stem was also investigated. The results were summarized as follows : The values of collapse in each species were great in order of Quercus dentata, Quercus variabilis, Quercus aliena and Quercus mongolica and the values were higher in heartwood than in sapwood in all of specimen. MC, basic density, P and Q were important factors which affected on the occurance of collapse and the collapse phenomenon was decreased from pith to bark.