• Journal of Korean Society of Forest Science
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• v.113 no.2
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• pp.187-197
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• 2024

In this study, we aimed to identify the factors influencing post-fire mortality in Korean red pine (Pinus densiflora) using Cox's proportional hazards model and analyze the impact of these factors. We monitored the mortality rate of fire-damaged pine trees for seven years after a forest fire. Our survival analysis revealed that the risk of mortality increased with higher values of the delta normalized difference vegetation index (dNDVI), delat normalized burn ratio (dNBR), bark scorch index (BSI), bark scorch height (BSH) and slope. Conversely, the risk of mortality decreased with higher elevation, greater diameter at breast height (DBH), and higher value of delta moisture stress index (dMSI) (p < 0.01). Verification of the proportional hazards assumption for each variable showed that all factors, except slope aspect, were suitable for the model and significantly influenced fire occurrence. Among the variables, BSI caused the greatest change in the survival curves (p < 0.0001). The environmental change factors determined through remote sensing also significantly influenced the survival rates (p < 0.0001). These results will be useful in establishing restoration plans considering the potential mortality risk of Korean red pine after a forest fire.

• Journal of Korean Society of Forest Science
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• v.24 no.1
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• pp.53-61
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• 1974

Pine forests existing in Hong-do island were examined as regarding such characteristics, tree form, needle length, branch diameter, bark colors, ratio of summer wood to springwood, location and number of resin canal and other measurements. Hong-do island, located the furthest west part of Korea, suports only Pinus densiflora but very few Pinus thunbergii, in fact the present authors could not find any black pine individuals at all through investigation. Checking 14 individual trees of red pine, more than age of 20, of the genetic contamination by black pine, in a certain degree, exist. Here, a very dense foliage type and a very sparse foliage type tree of red pine growing nearby was examined and the unique fact was that each of those type has only one (average number 1.3) accessory resin canal, while other trees have three as minimum or more. The present authors thought this island had not been covered by any Pinus thunbergii but by Pinus densiflora. It was thought that Pinus thunbergii stands grown along the sea-coast of Korean Peninsula are pollen donors to this island.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.666-675
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• 2020

This study investigated mechanical characteristics of pine trees in Yeongdong (Goseong-gun), Yeongseo (Hongcheon-gun), and Yeongnam (Bonghwa-gun) to define differences in the material quality among pine trees of the three regions. The compressive strength, hardness and shear strength of pine trees of each region were measured. There were no differences in the compressive strength of the juvenile woods among the regions, while the heartwood and sapwood in Bongwha generally showed the highest compressive strength followed by those in Hongcheon and in Goseong. The hardness of the cross-section of pines in Bonghwa was the highest, and in terms of the hardness of the radial and tangential sections, pines in Goseong topped the list.. There were no difference among heartwoods of each region in terms of the shear strength, but, but sapwood from Bonghwa had higher shear strength than those of the other two regions, which may be attributed to differences in tracheid length and microfibril angle among pines in each region. This study identifies the quality differences among pines of different region, and therefore, is expected to add value by helping choose the domestic pine tree material effectively and selectively, and also select a plus tree.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.499-505
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• 2013

Pine wilt disease has known as a serious forest disease in East Asia such as Japan, Korea and China. Fumigation and burning are considered as best way to treat infected tree at early detection. For investigate spectral reflectance characteristics of infected trees, periodic measurement has been done in both infected and non-infected trees. Infected and non-infected trees' reflectance (400 nm~2,500 nm wavelength) are detected from June to October with GER3700 spectrometer. Noise of reflectance data was corrected using cubic spline interpolation method. Reflectance was changed in most of infected trees with ranges Red (600 nm~700 nm) and Middle Infrared (1,400 nm~1,500 nm) within two months after injected by Pine Wood nematode (PWN), but there was no differences in non-infected trees. Infected and non-infected trees were compared statistically in each period. As a result, we found that a statistically significant difference was occurred at Red and Middle Infrared (MIR) 2 months after injection (p<0.05), however, no significant difference in near infrared (p>0.05). Therefore, the early detection of infested pine trees by PWN may possible through detecting the change of spectral reflectance at red and MIR.

• Journal of Korean Society of Forest Science
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• v.61 no.1
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• pp.20-26
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• 1983

Some aspects of the change in the rate of gall formation on the red pine, Pinus densiflora Siebold et Zuccarini, by the pine needle gall midge, Thecodiplosis japonensis Uchida et Inouye, were investigated at the coastal area in Chung Nam-Do from 1977 to 1982, and were analyzed with the nationwide survey data for 2 years from 1980 to 1981. The results obtained were as follows; the gall formation rate in several areas was compared between two consecutive generations. Four regression equations were established, with X as the gall formation rate in N year and Y as that in (N+1) year: 1) Y=11.2+1.15X (r=0.833) for the stands facing north on the phase of insect population increase, 2) Y=14.3+0.82X (r=0.739) for the stands facing south on the phase of population increase, 3) Y=7.3+0.46X (r=0.478) for stands facing north on the phase of population decrease and 4) Y=11.4+0.19X (r=0.086) for stands facing south on the phase of population decrease. After invasion of the pine needle gall midge into a red pine forest, gall formation rate increased for 6 consecutive generations and then decreased to low level within a period of another 6 years.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.666-674
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• 2014

In this study, we investigated mechanical properties of Korean softwoods after applying thermal compression. Density of compressed woods was notably increased with thermal compression. In case of 50% compression set, density of Korean pine (Pinus koraiensis), Japanese red pine (P. densiflora), and Larch (Larix kaempferi) wood was increased by 71%, 74%, and 76%, respectively, when compared to the control group. The strength of woods was increased and quality of the woods became homogeneous with an increases in the compression set. On the 50% compression set, the compressive strength, bending strength, and hardness of Korean pine wood was increased by 76%, 83%, and 55%, respectively compared to the control group. Longitudinal compressive strengths of Japanese red pine wood increased by 69%, 130%, and 76%, respectively and those of Larch wood increased by 77%, 120%, and 44%, respectively. In thermal compression wood, mechanical properties of Larch wood was the highest, while those of Korean pine wood were the lowest. However, Japanese red pine wood showed the highest in the increase rate of mechanical properties after the thermal compression.

• Journal of Ecology and Environment
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• v.35 no.4
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• pp.307-311
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• 2012

This study was conducted to evaluate the dynamics of soil respiration (total soil and heterotrophic respiration) following fertilizer application in red pine forests. Fertilizer (N:P:K = 113:150:37 kg/ha), which reflects current practices in Korean forest, was applied in April 2011, and total soil and heterotrophic respiration rates were monitored from April 2011 to March 2012. Monthly variation of total soil and heterotrophic respiration rates were similar between the fertilizer and control treatments, as soil temperature was the dominant factor controlling the both rates. Total soil respiration rates during the study period were not significantly different between the fertilizer (0.504 g $CO_2\;m^{-2}\;h^{-1}$) and control (0.501 g $CO_2\;m^{-2}\;h^{-1}$) treatments. However, the proportion of heterotrophic respiration was higher in the fertilizer (78% of total soil respiration rates) than in the control (62% of total soil respiration rates) treatments. These results suggest that current fertilizer practices in Korea forest soil do not substantially affect total soil respiration rates.

• Journal of the Korean Wood Science and Technology
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• v.22 no.4
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• pp.37-42
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• 1994

The adsorption of water vapor and equilibrium moisture content(EMC) of the specimens for four softwood species dried by conventional- and high temperature method and equilibrated to 15% of the target EMC condition at 25$^{\circ}C$ were determined by oven drying method and with moisture meters. The amount of adsorption for high temperature dried red pine was significantly higher than that of conventional kiln dried wood, while those of eastern white pine, eastern hemlock and Norway spruce were not significantly different between drying methods. EMCs of these four species determined by oven drying method and with capacitive admittance moisture meter were not significantly different between drying methods. EMC of high temperature dried red pine determined with resistance moisture meter was significantly higher than that of conventional kiln dried wood. But EMCs of other species did not show significant difference between drying methods. EMCs of conventional and high-temperature dried wood determined with electronic moisture meters, especially in the case of the capacitive-admittance moisture meter measurement, were lower than that determined by oven drying method.

• Journal of Ecology and Environment
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• v.29 no.1
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• pp.23-27
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• 2006

This study was conducted to evaluate forest carbon cycling and soil $CO_2$ efflux rates in a 42-year-old pine (Pinus densiflora) stand located in Hamyang-gun, Korea. Aboveground and soil organic carbon storage, litterfall, litter decomposition, and soil $CO_2$ efflux rates were measured for one year. Estimated aboveground biomass carbon storage and increment in this stand were $3,250gC/m^2\;and\;156gC\;m^{-2}yr^{-1}$, respectively. Soil organic carbon storage at the depth of 30 cm was $10,260gC/m^2$ Mean organic carbon inputs by needle and total litterfall were $176gC\;m^{-2}yr^{-1}\;and\;235gC\;m^{-2}yr^{-1}$, respectively. Litter decomposition rates were faster in nne roots less than 2 mm diameter size ($<220\;g\;kg^{-1}yr^{-1}$) than in needle litter ($<120\;g\;kg^{-1}yr^{-1}$). Annual mean and total soil respiration rates were $0.37g\;CO_2m^{-2}h^{-1}$ and $2,732g\;CO_2m^{-2}yr^{-1}$ during the study period. A strong positive relationship existed between soil $CO_2$ efflux and soil temperature (r=0.8149), while soil $CO_2$ efflux responded negatively to soil pH (r=-0.3582).

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.589-601
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• 2011

The purpose of this study was to investigate changes in the cooking process of $Pat-juk$(red beans porridge), $Jat-juk$(pine-nut porridge) and $Tarak-juk$(milk porridge) in cooking books published after Korean modern era, approximately from late 19th century to the present. We analyzed 11 historical cook books were analyzed. It is found that the amount of red beans used for $Pat-juk$ was the same or more than that of rice but never less than rice. Only one cook book suggested sugar as seasoning for final taste, but all the other cook books mentioned salt for final taste. $Hangukeumat$(1987) suggested the method for obtaining optimum color for $Pat-juk$. After smashing and passing through the cooked red beans, collecting the red bean water to boil first and then adding the passed through red beans to boil together, in which rice will be added the last to be boiled. For $Jat-juk$, the ratio of the amount of pine-nut and rice were varied among cook books that the amount of pine-nut can be more, same or less than rice. $Jat-juk$ can have salty or sweet, so sugar, honey or salt were used for final seasoning. Pine-nut and rice were cooked together or cooked successively depending on cook books. The changes in cooking procedures of $Tarak-juk$ were the portion of milk used and the method of preparing rice before making the porridge. Firstly, the portion of milk increased over time. $Tarak-juk$ can be also tasting both sweet or salty, so sugar or salt was used for final seasoning. Secondly, two method of preparing rice were found; one is that rice was ground after soaking in water and the other is that rice was ground and toasted before putting into the porridge. When the ground rice was toasted, the milk was added with water at the same time because the cooking time of the porridge with toasted rice was shortened so that the milk could be added earlier than the other method without the risk of sticking on the bottom of the pot. In further studies, the cooking procedures used in the previous period of the late 19th century should be examined. Also after restoring all the cooking methods suggested in cook books, the comparison of the sensorial and nutritional value needs to be carried out for applying or reinventing new recipe for food industry.