• Journal of Forest and Environmental Science
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• v.34 no.6
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• pp.472-480
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• 2018

This study was conducted to estimate carbon storage in Quercus mongolica stands based on stand age class, and to provide basic data on the carbon balance of broad-leaved forests of Korea. The research was conducted at the experimental forest of Kangwon National University, Hongcheon-gun County, Gangwon-do Province, Korea. Three plots were set up in each of three Q. mongolica forest stands (III, V, and VII) to estimate the amount of carbon stored in Q. mongolica aboveground vegetation, coarse woody debris (CWD), organic layer, mineral soil, and litterfall. The carbon storage of the aboveground vegetation increased with an increase in stand age, while the carbon storage ratio of stems decreased. The carbon storage of the organic layer, CWD, and litterfall did not show any significant differences among age classes. In addition, the carbon concentration and storage in the forest soils decreased with depth, and there were no differences among age classes for any soil horizon. Finally, the total carbon storage in the III, V, and VII stands of Q. mongolica were 132.2, 241.1, and $374.4Mg\;C\;ha^{-1}$, respectively. In order to predict and effectively manage forest carbon dynamics in Korea, further study on deciduous forests with other tree species in different regions will be needed.

• The Korean Journal of Ecology
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• v.18 no.3
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• pp.385-395
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• 1995

Species effects on soil nitrogen mineralization and nitrification in the top 15 cm of soil were evaluated using the buried-bag incubation method in three coniferous plantations in the Kwangneung Experimental Forest, Kyonggi Province. The plantations were established on a similar soil in 1927, and included Larix decidua, Pinus strobus, and Thuja occidentalis. Ten soil samples within each plantation were taken during an entire growing season (May 2~Oct. 30, 1994). Mean daily nitrogen mineralization rates during 45-day in situ soil incubations were significantly different among species and incubation dates. Growing season nitrogen mineralization also differed significantly among species and ranged from 47.7 mg N/kg soil for Larix decidua to 21.5 ma N/kg soil for Thuja occidentalis. Growing season nitrification differed significantly among species and comprised from 93% to 100% of the total growing season nitrogen mineralized. We speculated that organic matter contents and quality might control nitrogen mineralization and nitrification in these soils.

• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.123-133
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• 2013

This paper presents experimental and numerical tests on a recently developed timber column concealed base joint. This joint was designed to replace the wood-wood connection found in the post-and-beam structure of Hanok, the traditional Korean timber house. The use of metallic connectors provides an increased ductility and energy dissipation for a better performance under reversed loading, especially seismic. In this study, we investigate the performance of the joint under pseudo-static reversed cyclic moment loading through the study of its ductility and energy dissipation. We first perform experimental tests. Results show that the failure occurs in the metallic connector itself because of stress concentrations, while no brittle fracture of wood occur. Subsequent numerical simulations using a refined finite element model confirm these conclusions. Then, using a practical modification of the joint configuration with limited visual impact, we improve the ductility and energy dissipation of the joint while retaining a same level of rotational strength as the originally designed configuration. We conclude that the joint has a satisfying behavior under reversed moment loading for use in earthquake resistant timber structure in low to moderate seismicity areas like Korea.

• Journal of the Korean Wood Science and Technology
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• v.33 no.2 s.130
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• pp.56-64
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• 2005

This study was performed to investigate the frequency of blue staining fungal species collected from pine trees, Experimental Forests of Kangwon National University in Korea based on their morphological characteristics. In addition the tolerance to fungicide, Woodguard, was assessed to get basic knowledges for preventing blue stain of wood. Totally Leptographium-type fungi were dominated by 79.3% among Ophiostomatoid fungi associated with scolityd bark beetles in pine trees. Leptographium-type Ds-isolates which have unusual morphology were collected as frequency of 17.0%. The most distinct differeneces of these Ds-isolates from L. procerum were the presence of roughened hyphae and flask-shaped conidiophores that have never been mentioned formerly for L. procerum, but since these Ds-isolates formed black concentric rings being a property of L. procerum, the Df-isolates were characterized as Leptographium-type fungi, which are the most common species with the highest frequency by 33.2% in this particular area. According to our experimental results, Leptographium-type Ds- and Df-isolates were very resistant to fungicide, Woodguard, therefore it was suggested that a new method for wood protection from the blue staining fungi should be developed. Exact identification of blue staining isolates collected from pine trees is keep going.

• Journal of Forest and Environmental Science
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• v.34 no.1
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• pp.82-86
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• 2018

Loblolly pine (Pinus taeda L.) is widely distributed in the southern part of the United States and it has been used as a major economic species in the region due to its excellent growth and stem straightness. The tree also grows only in the southern part of Korea because it is susceptible to cold. Recently climate changes have had widespread impacts on forest trees. Thus, the use of good quality seeds is prerequisite for assessing assisted migration adaptation trial. In this study, we conducted to investigate its cone and seed characteristics of each family, which is expected to improve seeds productivity for planting valuable timber trees. A total of 14 families were selected from the experimental forest in Boseong, Jeonnam province in 1981. The seed production capacity was estimated to range from 87.2 to 129.4 among families and the average was 111.3. The number of aborted ovules was investigated in the range of 11.4 to 29.5 for the first test and 7.4 to 22.2 for the second test. The average number of empty and filled seeds was 1.4 and 79.2 per cone, respectively. Based on the results, we can conclude that there is a strong correlation between the number of fertile scale and the seed production ability.

• Hwankyungkyoyuk
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• v.23 no.3
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• pp.97-114
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• 2010

The aims of this study are to develop and apply a Nature Game program for the ecological experience learning in Jeju Gotjawal forest and analyze the environmental sensitivity change of the students. The results obtained in 4th graders of A elementary school of Seogwipo-city are as follows: It was found that attention, susceptibility and practice will of environment protection for forest environment of the experimental class were significantly higher than those of the comparison class. And it was found that interest and curiosity into forest environment were also elevated in the results of the qualitative evaluation, suggesting that we could get the effect of developed Nature Game program on ecological experience learning. If various ecological experience learning programs considering the regional-specific characteristics are developed to cause students' interest and curiosity, students would come to participate in the protection activity of environment aggressively a little more.

• Journal of Information Processing Systems
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• v.15 no.1
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• pp.159-168
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• 2019

Accurate forest fires detection algorithms remain a challenging issue, because, some of the objects have the same features with fire, which may result in high false alarms rate. This paper presents a new video-based, image processing forest fires detection method, which consists of four stages. First, a background-subtraction algorithm is applied to detect moving regions. Secondly, candidate fire regions are determined using CIE $L{\ast}a{\ast}b{\ast}$ color space. Thirdly, special wavelet analysis is used to differentiate between actual fire and fire-like objects, because candidate regions may contain moving fire-like objects. Finally, support vector machine is used to classify the region of interest to either real fire or non-fire. The final experimental results verify that the proposed method effectively identifies the forest fires.

• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.516-524
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• 2008

We investigated on the distribution of nutrient contents (N. P and K) in current and one-year old needles of Korean pine, Pinus koraiensis, to understand the physiological effects of alternate bearing. One experimental set was designed with three types of cone number (one, three and five) under natural state and cone number of another one was controlled by thinning. Test samples were separated to collect into three fractions; current needles on the shoot and one-year old needles above and under the cone. On the branch without cone, N, P and K concentrations in needles on the shoot were higher than those in needles of one-year old branch. At natural state, needle P concentration was the lowest in needles on the five-cone branch in August. Macronutrient concentrations were the lowest in needles above the cone, which was remarkably observed in needle K concentration. Under cone thinning, N. P and K concentrations were the highest in needles on one-cone branch and the lowest in needles on five-cone branch. Needle nutrient concentrations were the lowest in needles above the cone, which was remarkably observed in the needle on five-cone branch. In conclusion, the current needles of the shoot and cones are a strong sink of nutrient like N. P and K, and the increase of cone number influences nutrient removal from needles.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.1
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• pp.63-70
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• 2015

Objectives The purpose of this study is to understand the research trend of reports on forest therapy so far and analyze the Korean medicine therapy being applied in forest therapy programs. Methods We ran a keyword search on domestic databases with the following keyword 'forest therapy, forest healing, forest treatment, recreational forest, forest bath, forest experience'. The search took place in December 2014 and there was no limit to search time. A total of 334 forest therapy articles have been selected. Results The number of research on forest therapy continued to rise from 1985, with 334 articles being published from 84 journals. When those 188 articles were sorted by their contents and methods, except 146 articles of survey on simple satisfaction, recognition and visting, 94 were clinical studies, 79 were literature studies, 15 were experimental studies. Of the 94 clinical researches, there were 52 CCTs (Controled Clinical Trials), 39 ODs (efficacy studies with either a controlled or an Other than controlled Design) and 3 RCTs (Randomized Clinical Trials). Among the clinical researches, there were a total of 21 studies that used Korean Medicine programs, and meditation was the most popular, being used in 18 studies. Herbal food and tea therapy and Qigong were used in 3 studies each, and Korean medicine music programs were used in 2 studies. Conclusions A systematic and standardized Korean medicine forest therapy program must be developed, and based on the program, more research treating diseases should be conducted.

• 한국생태학회:학술대회논문집
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• 2002.08a
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• pp.127-131
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• 2002

In order to elucidate the characteristics of standing crop biomass, production and nutrient content of dead bole in mature ecosystem, we surveyed the dynamics of decaying bole of old-aged deciduous forest in 1993 and 2002 in Kwangnung Experimental Forest Station. In addition, we and estimated annual bole production, water content, wood density and nutrient content and compared the results with that of temperate ecosystem. Total dead wood biomass was estimated to be 5.6ton/ha in 1993 and 17.6ton/ha in 2002. Standing dead tree accounted for a total of 1.1ton/ha in 1993 and 4.8ton/ha in 2002, which was 20% and 27% of the sum of dead bole mass in 1993 and 2002, respectively. Annual production of bole biomass was 1.3 ton/ha/yr. These values fall into the low range of dead wood biomass for the mature temperate ecosystems. Tree species composing standing bole was mainly Quercus and Carpinus trees. This bole species composition resembles alive species composition of this forest. Water content of bole increased as positive logarithmically, but wood density of bole decreased as negative exponentially along with the progress of decay. N, P, Ca and Mg concentrations in decaying boles generally increased with decay, except for K. Annual nutrient input via dead bole is 1.6kg/ha/yr for N, 0.04 kg/ha/yr for P. 1.0 kg/ha/yr for K, 1.7kg/ha/yr for Ca and 0.3 kg/ha/yr for Mg, respectively.