• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.762-771
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• 2017

Predicting the amount and distribution of moisture content within wood allows calculating the various mechanical dynamics of the wood as well as determining the drying time. For boxed-heart wood with a large cross-section, since it is difficult to measure the moisture content of the interior, it is necessary to predict the moisture content distribution. This study predicted the moisture movement in boxed-heart red pine timber, during high temperature drying, by using the three-dimensional finite difference method for the efficient drying process. During drying for 72 h, the predicted and actual moisture content of the tested wood tended to decrease at a similar rate. In contrast, the actual moisture content at 196 and 240 h was lower than predicted because surface checking of the wood occurred from 72 h and excessive water emission was unexpectedly occurred from the checked and splitted surface.

• Journal of Plant Biology
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• v.17 no.4
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• pp.18-22
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• 1974

Counts of herb stems were made with each systematic grid sized 10cm by 1300cm within six apparently homogeneous herb layers under the open young Japanese red pine, Pinus densiflora, stands. The stands had often been subjected to strong human interferences such as burning, cutting, grazing, and denuding since human settlement until the conservation scheme practiced in these stands for last decade. In addition, amounts of loss of ignition and field capacity were determined to detect soil heterogeneity among and within the stands. The values of information measure of diversity(H), and Hurlbert's probability of interspecfic encounter(Δ), obtained here do not show any consistent correlation. The amount of interspecific competetion(Δ1), the ratio of interspecific to intraspecific competetion(Δ4), Levin's niche breadth(Sh), and species evenness(V), increase, while the amount of intraspecific competetion decrease, as the soil factors become favorable. One stand examined does not follow the above trends, which is more young and shows strong within site heterogeneity of the soil factors. The stand includes pioneer species which is not detectable without detailed observation. It is argued that in stable or favorable environment more intense interspecific competetion and less intraspecific competetion might occur, but this situation does not necessarily always bring smaller niche breadth. In this connection, the results support Hurlbert's contention that the two components of diversity should be analyzed separately.

• Journal of the Korean Wood Science and Technology
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• v.16 no.4
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• pp.61-69
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• 1988

Recently the automization of wood manufacturing and the development of CNC machine tools becomes the center of interest. Cutting mechanism, tool wear and the roughness of machined surface have been studied. In the studies about wood for special uses, concrete data of cutting is desired. While Pinus densiflora is characterized that heartwood develops as age increases, Chunyang District has the characteristic of strength, red color, relatively regular chap and high heartwood - percentage. But there is no data about cutting this wood, Chunyang District. In this study face milling by sintered carbide tool was excuted to Chunyang District. Cutting force, Surface roughness and states were investigated with regard to cutting speed. Example results were as follows; 1) Mean cutting resistance against lateral component force and longitudinal component force decreased rapidly up to cutting speed of 155 m/min, and remains constant above this speed. 2) The surface roughness of cutting surface lowered as cutting speed increased, regardless of fiber formation. Radial rougness of fiber is larger than lineal surface roughness. 3) Increase in Cutting speed made machining mark restrained. Down-milling showed larger marks than up-milling.

• Research in Plant Disease
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• v.18 no.2
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• pp.101-108
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• 2012

In 2006, pinewood nematode, Bursaphelenchus xylophilus, was isolated from about 50 years old trees of Pinus densiflora and P. koraiensis showing leaf-wilt and -drying symptoms in Gwangju, Gyeonggi-do and Chuncheon, Gangwon-do. Isolation of pinewood nematodes from sapwood of infected pine trees showed no difference in population density between tree species and among the sampling heights on the main stem. Migration of pinewood nematodes in the host tree were investigated by inoculation of red pine (P. densiflora, 3 years old) seedlings with B. xylophilus. The nematodes seemed to move in red pine seedlings prior to multiplication and it might have taken about 20 days to start multiplication and expression of symptoms including wilt and dieback. In initial time after inoculation, nematodes started migration through the cortical resin canal from inoculated site and further showed upward and downward movements. More nematodes were observed in cortical resin canal during early period of inoculation and later in resin canal of xylem and tracheid also while, the pith still remained free from nematode. The density of B. xylophilus was higher in seedlings of low-vigor with poor root growth than in seedlings of normal root growth. Seedlings showing high density of B. xylophilus exhibited stem discoloration and secondary infection by fungus at the inoculation site.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.3
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• pp.255-262
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• 1996

This study was carried out to investigate the effects of soil fertilizers on wax content, contact angle, mineral nutrient content of Japanese red pine (Pinus densiflora Sieb, et Zucc.) leaves and soil acidity of Japanese red pine communities in Namsan and Kwangnung to see whether they can recover forest decline. Japenese red pine communities were treated with $Ca(OH)_2$, $Mg(OH)_2$, $Ca(OH)_2+Mg(OH)_2$+C.F.(compound fertilizer) in a randomized complete block design with 3 replication from November, 1990 through October, 1993. Wax content, contact angle value and mineral nutrient content of Japanese red pine leaves and soil pH of communities were measured and the results obtained are as follows: 1. Contact angle value and wax content of Japenese red pine leaves increased when the fertilizers were applied in soil. The order leaves grew, the smaller their contact angle values. 2. K and Ca contents of Japanese red pine leaves were higher in Namsan than in Kwangnung, whereas Mg content was higher in Kwangnung. K and Mg contents of the leaves increased with fertilization both in Namsan and Kwangnung. 3. Soil acidity of pH 4.2 ~ 4.3 was shown in Namsan and pH 4.6 ~ 4.9 in Kwangnung. No acidity changes were shown when the fertilizers were applied in soil. However with the lapse of the soil fertilizer application time, there was the indication that soil pH became higher in the fertilizer treatments than in the control.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.463-468
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• 1993

In order to elucidate the translocation of the systemic insecticide, phosphamidon (2-chloro-2-diethylcarbamoyl-1-methylvinyl dimethyl phosphate), treated to pine trees against pine leaf gall midges (Thecodiplosis japonensis Uchida et Inouye), $[vinyl,\;carbonyl-^{14}C]$ phosphamidon was implanted into the trunks of 10-year-old Korean red pine (Pinus densiflora Sieb. et Zucc.) and Japanese black pine (Pinus thunbergii Parl.), respectively. The upward movement rates of the chemical within Korean red pine in July and Japanese black pine in December were ca. 10 cm/hr and 2 cm/hr, respectively. The original radioactivity level persisted up to 75 days after treatment throughout the whole tree in Korean red pine in July, whereas it did up to 150 days in Japanese black pine in December. The chemical was translocated up to the top at the insecticidal level within 3 days after treatment in July, whereas in December it was within 15 days. The translocation of the chemical was much dependent upon pine tree species and the treated season. Methanol was suitable for the extraction of phosphamidon and its metabolites from pine needles. Autoradiography of the methanol extracts of pine needles collected from the treated pine trees proved that phosphamidon broke down very quickly within pine trees (ca. 80% metabolized within 7 days).

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.452-460
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• 2000

This study was to investigate the growth characteristics, physiological adaptation of Pinus densiflora(Japanese Red Pine) seedlings at the artificial canopy gap in the Quercus acutissima plantation and to analyze its natural regeneration mechanism. Photosynthetic and transpiration rates were analyzed by different levels of photosynthetically active radiation and by seedling growth. Comparing to seedlings at the open area, those at the canopy gap showed more growth in height than in diameter with different levels of light quality and low light intensity, and the increase rate of dry weight was higher in the aboveground than in the underground, maintaining relatively high T/R rate. The C/F(the ratio of non-photosynthetic organs to photosynthetic organs in dry weight) of the aboveground at the canopy gap was higher than that at the open area by 0.1~0.2, while light saturation and light compensation points at the canopy gap were lower than that at the open area by $300{\mu}mol\;m^{-2}s^{-1}$ and 40%, respectively. The seedlings appeared to have shade tolerance to a certain extent at the young growth stage despite Pinus densiflora is typically classified shade-intolerant species. With light intensity lower than $400{\sim}450{\mu}mol\;m^{-2}s^{-1}$, photosynthetic rate and water use efficiency relatively increased by effective use of light energy.

• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.266-274
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• 2014

To extend the understanding of the pyrolysis mechanism of wood, we have investigated wood dust charcoal and condensate of volatile organic compounds (VOC) obtained during the pyrolysis of red pine (Pinus densiflora Sieb. et Zucc.) at $180{\sim}450^{\circ}C$ using elemental analysis, IR and GC/Mass. The effect of activation process on the charcoal structure also has been studied by comparing elemental analysis and IR data of charcoal carbonated at $600^{\circ}C$ and charcoals activated at $750^{\circ}C$. The results show that pyrolysis of wood has mainly started near at $240^{\circ}C$ and its chemical components did not changed much up to $270^{\circ}C$. However, the element contents and IR spectra drastically changed at $300^{\circ}C$. The fact that IR peaks related to the aromatic ring of lignin are observed in the charcoal pyrolized at $450^{\circ}C$ indicates that a small part of lignin still remains at this temperature. The chemical structure of the activated charcoal seems almost unaffected by the activation time.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.402-407
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• 2011

The objectives of this study were to analyze the crown vertical structure, crown bulk density, and to develop regression models for predicting crown fuel load using the data from 10 destructively sampled Pinus densiflora trees in Bonghwa, Gyeongbuk. The fuel loads were observed higher in the middle portion of the vertical distribution of crown followed by the lower portion and upper portion of Pinus densiflora, respectively. Approximately 25% crown fuel load was found in the needle while 33% was observed in the branches with <1 cm diameter with a total of 58% available fuel loads. The average crown bulk density was $0.45kg/m^3$, and $0.27kg/m^3$ of this was available in the needles and branches with <1 cm diameters. The resulting models in linear equations were able to account for 84% and 88% of the observed variation, while the allometric equations with diameter at breast height as the single predictor showed better results to account for 90% and 95% of the observed variation in the available crown fuel loads and total crown fuel loads, respectively. The suggested equations in this study could provide quantitative fuel load attributes for crown fire behavior models and fire management of red pine stands in Bonghwa areas.

• Journal of the Korea Furniture Society
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• v.20 no.3
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• pp.247-252
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• 2009

The objective of this study was the dimensional stabilization of Korean red pine (Pinus densiflora) wood by the water-based thermosetting resin. A commercial melamine-formaldehyde resin was impregnated into wood samples and cured. The weight and dimensional change of woods treated by the resin, and the absorption and dimensional behavior of treated woods were investigated. The melamine-formaldehyde resin treatment improved significantly the dimensional stability of pine wood and showed about 40% of antiswelling efficiency. The mechanism of dimensional stabilization was interpreted as the complicated reason, such as bulking effect by the resin in cell wall, mechanical restraint and/or blocking of hygroscopic site by the resin in lumen.