• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.475-486
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• 2015

This survey was conducted in order to investigate the vascular plants of Hak Reservoir Valley in the DMZ Area, Korea. The vascular plants were collected six times (from April 2014 to November 2014) and consisted a total of 238 taxa; 69 families, 172 genera, 206 species, 2 subspecies, 26 varieties and 4 forms. The observed rare plant species as designated by Korea Forest Service were 3 taxa including Carex capricornis Meinsh. ex Maxim., Acorus calamus L., Penthorum chinense Pursh. Endemic plant species were 2 taxa including Salix koriyanagi Kimura, Clematis brachyura Maxim. 17 taxa were listed as specific plant species based on phytogeographical in the investigated area. 25 taxa were recorded as naturalized plants, and their Naturalization Ratio and Urbanization Index were recorded as 10.46%, and 7.78%, respectively. Of the 238 taxa listed; 105 were pasturing plants, 92 edible plants, 76 medicinal plants, 24 ornamental plants, 6 stain plants, 4 timber plants, 2 fiber plants, 2 industrial plants and 55 unknown plants.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.18-27
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• 1998

To investigate the restoration progression on soil physical properties and vegetation at the surface of logging road affected by timber harvesting operation. This study was carried out at logging roads constructed from 1989 to 1994 in Mt. Baekwoon, Kwangyang, Chollanam-do. Judging from the analysis of soil hardness, there were significant changes in the depth of soil between 5 and 10cm. Soil hardness was recovered from the compacted condition to the natural forest condition after 9 years passed. Soil macroporous ratio (pF2.7) of topsoil was higher than that of deep soil. Soil moisture retention of topsoil was more improved than that of deep soil. From the view of soil bulk density, the necessary time for recovering to the undisturbed condition of forest soil was about 10 years in the logging road left. Soil physical properties such as soil bulk density and porous ratio were recovered as time passed. Improved soil physical properties promoted the plant recovery on the logging road surface. The dominant species on the logging roads were Comus kousa, Prunus sargentii as overstory species, Rubus crataegifolius, Lespedeza bicolor as understory species, and Saussurea gracilis, Pteridium aquilinum var. latiusculum as herbaceous species. The plant recovery of bank-slopes was faster than that of cut-slopes and road surface. In progress of year, average plant coverage were 70 to 90% in cut- and bank-slopes and 30 to 60% on the logging road, surface which was elapsed 9 years after logging road construction. Therefore, additional planting and seeding work could be effective to the soil condition and vegetation restoration.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.166-166
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• 1982

This study has been made to make an observation regarding present status of the coal mine props which is desperately needed for coal production, despite of great shortage of the timber resources in this country, and investigate the effects of diffusion process on the decay resistances of the mine props as applied preservatives of Malenit and chromated zinc chloride. The results are as follows. 1. Present status of the coal mine props Total demand of coal mine props in the year of 1975 was approximately 456 thousand cubic meters. The main species used for mine props are conifer (mainly Pinus densiflora) and hardwood (mainly Quercus). Portions between them are half and half. With non fixed specification, wide varieties of timber in size and form are used. And volume of wood used per ton of coal production shows also wide range from 0.017 cubic meter to 0.03 cubic meter. 2. Decay resistance test a) The oven dry weight decreased between untreated specimen and treated specimen has not shown any significantly, although it has shown some differences in average values between them. It may be caused by the shorter length of the test. b) The strength of compression test between untreated specimen and treated specimen has also shown the same results as shown in case of weight decrease. Reasons assumed are the same. c) The amounts of the extractives in one percent of sodium hydroxide (NaOH) between untreated and treated specimen have shown the large value in case of untreated specimen than that of treated. 3. The economical benifit between untreated and treated wood when applied in field has seen better in long tenn base in case of treated wood, although the primary cost of treated wood add a little bit more cost than that of the untreated wood.

• Journal of Conservation Science
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• v.5 no.2 s.6
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• pp.51-56
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• 1996

This paper deals with the restoration of ancient wooden bridge foundation which excavated in Seta river Shiga Prefecture, Japan. Shiga Archeological Research started a marine archeological investigation of the bridge foundation in 1987. The bridge foundation stricture excavated and have since then recovered about a lots of woods and another materials. The bridge foundation structure constructed log, timbers and stones. The species of those waterlogged wood were identified as two types, hardwood and softwood. Hardwood(log : Cyclobalanopsis) was used for below foundation and softwood (timber' Chamaecyparis obtusa Endl. Cupreessaceae) was used for base structure. One of those timber sample dated by dendrochronology, we asked Dr. Misutani*. The softwood gave a felling date of 567 A.D. In result, the ancient Seta bridge foundation structure had constructed between Asuka and Nara period. We healed the news that ancient bridge foundation excavated at Woljyongyo site in Kyongju, Korea 1987. The bridge foundation Setakarahashi is similar in plane and structure to Woljyongyo structures. The Woljyongyo site report had be of value for reference. We had planning to restore those woods. Hardwood log was got serious damage. The water content varies from 400 to $600\%$. The other timbers water content varies about $200\%$. In the Shiga Center for Archaeological Operations and the Azuchi Castle Archaeological Museum, we set up the PEG impregnation tank. Those wooden objects treated by PEG method. PEG with a molecular weight of 4000. The treatment results may be considered satisfactory. The ancient wooden Seta bridge was reconstructed in Biwako Museum which established in Oct. 1996. We must take care of indoor exhibition environments. (*Nara National Cultual Properties Research Institute).

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.4
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• pp.225-233
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• 2018

One of engineered woods, glued laminated timber (GLT), can provide a constant level of performance and desired strength even if the quality of wood is low. Due to this fact, there is a growing interest in GLT using domestic species and related research has been carried out continuously. In addition, GLT is popularly being applied to the long-span or high-rise structures overseas. However, KBC 2016 does not allow the engineered woods to be used for middle and high-rise buildings by limiting height. Therefore, a proper design procedure and rationale should be clearly presented by the help of performance-based seismic design. With this background, the goal of this study is to establish a specific procedure for design of a 9-story building with RC shear walls and GLT frames according to the performance-based design of KBC 2016. The performance objectives were set according to KBC and the acceptance criteria for each goal were defined. The RC shear walls and GLT frames were designed by concrete and wood structure requirements, respectively. Analytical models were developed to reflect their nonlinear features, and both nonlinear static and dynamic analyses were conducted. Performance evaluation results showed that the shear walls have insufficient shear strength, so they were re-designed. Consequently, it has been confirmed that GLT frames can be applied to a 9-story office building with the assistance of RC shear walls and performance-based seismic design.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.521-530
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• 2011

Nowadays, market demand of structural Glulam is growing and diversifying. The durability of Glulam should be significantly considered when they are intended to apply for out-door use such as timber bridge and pergola. This study was aimed to develop the manufacturing process of preservative treated structural Glulam using domestic softwood species. 10 m long structural Glulam were manufactured from domestic pitch pine logs with CuAz-3 preservative treatment. At each manufacturing process, the production yield was evaluated. Finally, bending tests were performed to verify the structural performance of manufactured Glulam. From the results, it was shown that the preservative treatment process hardly influenced on the production yield. But domestic pitch pine was proved to not be suitable for making the preservative treated Glulam due to the large difference of preservative permeability between sapwood and heartwood.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.9-19
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• 1991

This paper discusses the applicability of two simulation models for a ten year planning period in order to predict changing forest conditions. Two simulation models therefore were developed and applied to 3,844 ha of a national forest in Kangwondo province, which is managed by Joongbu Forest District Headquaters. Growth functions of three species were derived and used to predict the residual timber volume over time. Two alternative cutting schedules caused 10-14% difference in the residual timber volume in the end of ten year planning period. This suggests the important of correct decision-makings of forest managers in forest management planning.

• Journal of the Korean Wood Science and Technology
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• v.32 no.4
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• pp.46-51
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• 2004

The objective of this study was to evaluate the applicability of high temperature drying to pitch pine (Pinus rigida) lumber, especially intended for use as lamina of structural glued laminated timber (glulam), to enhance the efficient utilization and provide added-value to that species. The high temperature schedule and drying procedures utilized were shown to be reasonable for drying glulam lamina due to the occurrence of small moisture gradients, minimal residual drying stress, and low warpage. Through preliminary tests, it was confirmed that residual resin at lamina surfaces did not adversely affect the gluing process. However, quantitative analysis of resin is required for developing a method to constrain the occurrence of pitch trouble with respect to decreasing long-term adhesive and finish durability of glulam in use after manufacturing. The final moisture content of high temperature dried lamina was much lower than target moisture content and discoloration was more severe than anticipated. In a further study, it will be necessary to determine the optimal drying conditions, such as temperature, humidity, drying time, and top load restraint level, which could best control discoloration, warpage, and moisture content of the lamina, while minimizing fuel expense.

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.109-115
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• 1988

Decrease of the planting area reduced fertilized area of forest. To accomplish the aims of natural regeneration, mini-rotation plantation, diminishing the rotation length, maintaining healthy forest and production of good quality timber, forest fertilization should be continued. In order to improve the deteriorate situation, slow-release fertilizer applied on top soil needs to be developed and aerial application will give diminished cost. Fertilization with tending before tree felling in forest will increase the effect of fertilizer more, Proper quantity of fertilizer by tree species and soil fertility should be found out in the future, Street trees, environmental forest near city and ornamental trees in the residential areas could be also included in this field.

• Journal of Forest and Environmental Science
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• v.32 no.1
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• pp.39-54
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• 2016

The present study analyzes the diversity and usage of NTFPs and evaluates their importance in the day to day life of the people of rural Meghalaya. People use 172 NTFPs belonging to 139 plant species mainly for food, medicine and fuelwood and to a lesser extent for construction, handicrafts and ornamental purpose. These 139 plants belonged to 117 genera and 70 families with Rosaceae, Poaceae and Fagaceae families as the dominant NTFP yielding families. Fruits from shrubs and trees are most commonly harvested by people. Collection and availability of NTFPs for use as food are more during the summer season, which is also the period with least availability of job. NTFPs for subsistence use are greater in number than those having commercial value. The most commonly harvested plant parts are fruits and leaves. Roots, rhizomes and whole plants are extracted in lesser quantity which is a positive approach from sustainability point of view. NTFPs and other forest products also form a vital part of the rural household's income generation activities.