• Mycobiology
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• v.29 no.4
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• pp.205-209
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• 2001

The Korean sawmills have recently recognized the importance of prevention of fungal discoloration due to increased losses in revenue. Before establishing integrated control strategies of fungal discoloration, more complete knowledge about causal organisms is needed. As a first step, we initiated a through survey of fungi colonizing commercially important softwood(Pinus dens flora, Pinus koraiensis, and Pinus radiata) logs and lumber in Korea. In this paper we report results obtained from Japanese red pine(Pinus densiflora) log study. In summer 2000, fungi were isolated from Japanese red pine logs in storage, and identified based on their cultural and morphological characteristics. A total of 595 fungi were isolated, representing 21 genera and 30 species. Mold fungi, mostly Trichoderma species, were the most frequently isolating fungi, representing more than half of all isolates. Dematiaceous fungi represented approximately one fifth of the isolates, and Rhinocladiella atorvirens was the most abundant in all samples. Opiostoma species represented 7% of all isolates from cores planted on malt extract agar(MEA) and the incidence of these species doubled with the addition of streptomycin and cycloheximide to MEA. The results indicate that Japanese red pine sapwood is susceptible to colonization by a variety of fungal species. As a result, control strategies that concentrate on one fungus may have limited success because of interference from competing flora.

• Journal of the Korean Wood Science and Technology
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• v.31 no.5
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• pp.96-103
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• 2003

This study was conducted to evaluate the tensile properties of metal plate connector for the domestic major softwoods, such as Korean red pine, Korean white pine, and Japanese larch. The maximum tensile load of Korean red pine was 3,612kgf in AA type, it was 1.2 and 1.7 times higher load than that of Japanese larch and Korean white pine. In EA type, it was 2,704kgf, and 1.1 and 1.5 times higher than the loads of Japanese larch and Korean white pine. The failure modes of metal plate connector were metal plate withdrawal, plate tensile failure, and wood shear block failure. The failure mode of Korean red pine connector was tensile failure of plate, that is reason of the high tensile load resistance for metal plate connections in Korean red pine. The mechanical properties of metal plate connector could be predicted by the Foschi model parameter. In the initial stage, the Korean red pine connector was stiffer than the other species. The design values for metal plate connector per tooth was 25, 22, and 15kgf for Korean red pine, Japanese larch, and Korean white pine in AA type and 19, 17, and 13kgf in EA type.

• 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.

• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.128-133
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• 2002

This study was conducted to investigate the influence of storage time on the sapstain development of Japanese red pine and Korean pine logs during storage in log yard, and their stain characteristics. Japanese red pine and Korean pine trees were harvested and cut into logs in mid January of 2001. These logs were transported to the two local sawmills where they were closely stacked in remote parts of log yard. The logs were then sampled destructively by cutting seven to nine 3-cm long discs along the length of each log at intervals of 3, 4, 5, 6, and 8 month after felling. The stain coverage and maximal radial penetration of stain were measured from the discs of the sampled logs after the isolation of causal staining fungi. The sapstain was primarily infested by the attack of bark beetles and the species of bark beetle was identified as Tomicus piniperda. The main fungal species isolated from stained wood was Ophiostoma species. Based on the present study, the logs could be stored in log yard until May without stain; but stain development was rapid after May and the severity of stain increased proportionally with storage time. Korean pine was more susceptible to fungal stain than Japanese red pine. During summer storage, decay started to develop in logs and the main species were identified as Tyromyces sp. and Schizophyllum commune. Information provided in this paper would be very useful to develop more effective control strategies for sapstain prevention in Japanese red pine and Korean pine logs.

• Journal of the Korean Wood Science and Technology
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• v.29 no.1
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• pp.52-59
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• 2001

The fixation characteristics of CCA and CCFZ in Japanese red pine, Japanese larch, and ezo spruce sapwood were compared at various temperatures and fixation conditions (drying and nondrying fixation). Fixation was monitored by the rates of reduction of hexavalent chromium to trivalent one, and optimal fixation time was estimated based on the results. The rate of fixation was highly temperature dependent, and the fixation rate of treated wood conditioned under nondrying conditions was much more faster than that under drying conditions, especially when the moisture content of treated wood was below fiber saturation point. Preservative types affected fixation; CCA-Type B had the highest fixation rate, followed by CCA-Type C and then CCFZ. The differences in fixation rates of preservative components were also observed among wood species; Japanese red pine fixed the fastest, followed by Japanese larch and then ezo spruce. Time required to complete fixation according to the fixation temperature could be predicted successfully using the regression equations between the temperatures and fixation time, regardless of conditioning methods, preservative types, and wood species.

• Journal of the Korean Wood Science and Technology
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• v.39 no.3
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• pp.244-251
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• 2011

The combustion characteristics were evaluated for Japanese Red Pine (Pinus Densiflora) and Korean Pine (Pinus Koraensis). These two species are widely used as building member of Korea-style house and volume density of Japanese Red Pine is relatively higher than that of Korean Pine. The combustion characteristics are closely connected with volume density. The differences of two species in both total heat release (THR) and average heat release rate (HRR) seemed to be resulted from the volume density. Toxicity of smoke from the specimens was increased because of fire-retardant treatment.

• Journal of the Korean Wood Science and Technology
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• v.28 no.1
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• pp.42-47
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• 2000

This study was designed to investigate the effect of treatment variables on CCA treatment of Japanese red pine (Pinus densiflora), Japanese larch (Larix leptolepis), and ezo spruce (Picea jezoensis) round posts. Variables included were duration of initial vacuum (30, 45, or 60 minutes) and maximum pressure applied (8.5, 10.5, or 14.0 kg/$cm^2$), and maximum pressure was maintained until refusal point was reached. Regardless of wood species, extending the duration of initial vacuum more than 30 minutes did not affect treatability. Increasing pressure did not affect preservative penetration; however, preservative retention was affected by pressure levels, particularly at higher level (14.0 kg/$cm^2$). Preservative penetration depth of Japanese red pine met a minimum requirement specified by Notification of Korean Forestry Administration (No. 1999-8) for hazard class H5 of CCA-treated wood. Penetration of preservative in both Japanese larch and ezo spruce was not deep because of shallow sapwood thickness of these species, so pretreatment such as incising should be considered if these species are treated with preservatives. Although retention in Japanese red pine was not significantly increased even with 14.0 kg/$cm^2$, that of refractory Japanese larch and ezo spruce was significantly increased with the application of 14.0 kg/$cm^2$. Effect of treatment variables on refusal time was unclear; however, it is cleared that the refusal time was shortened with the increase in sapwood thickness.

• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.55-59
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• 2003

The fixation and leaching characteristics of chromated copper arsenate (CCA Type C) and chromium- copper-fluoride-zinc (CCFZ) in domestic softwood (Japanese red pine, Korean pine, and Japanese larch) sapwood were investigated using the expressate method to follow chromium fixation and the American Wood-Preservers' Association (AWPA) leaching procedure to determine leaching properties after fixation. The rates of fixation were affected by preservative types; CCA was fixed much faster than CCFZ for all species evaluated. There were definite differences in the fixation rates of different species, with Korean pine requiring shorter to fix than the other species evaluated. Chromium fixation was greatly enhanced by elevated temperatures, and fixation time can be estimated according to fixation temperatures applied. The percentage of arsenic and zinc leached from domestic softwoods was relatively high compared to chromium and copper, indicating that there is still a relatively high unfixed arsenic and zinc components after complete chromium fixation in CCA-and CCFZ-treated samples, respectively.

• Journal of the Korean Wood Science and Technology
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• v.28 no.4
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• pp.61-71
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• 2000

The effect of the treatment with CCFZ, FR-4, and PEG400 from butt end on the dimensional stability and bending properties was examined. Three softwood species such as red pine, Korean white pine and Japanese larch and three hardwood species such as poplar, alder and oak were investigated in this research. Shrinkage of red pine, Korean white pine, poplar, and alder treated with PEG400 decreased. However, there was no significant decrease of shrinkage in Japanese larch and oak. The decrease of shrinkage when moisture content changed from about 20% to 10% was larger than that at any other phase. In regard to the effect of treatment on bending properties, bending MOE and MOR of all specimens treated with PEG400 decreased significantly. Especially in the case of red pine, poplar, and alder treated with PEG400, bending MOR reduced 9%, 14%, and 12%, respectively. Reductions of MOR of the hardwood was also much larger than that of the softwood. However, in all species, treatment with CCFZ and FR-4 did not affect the change of bending MOE and MOR significantly. Comparing the large specimen which also included heartwood with the small specimen which included only treated sapwood, there was a difference in the change of bending MOE and MOR between them. The large specimens of Korean white pine, alder and Poplar, which had a relatively low proportion of sapwood(18~22%), showed the decrease of MOR by 11~13% more than that of small specimens, while red pine, Japanese larch and oak, which had a relatively high proportion of sapwood(35~40%), showed little decrease. It means that bending MOE and MOR of structural wood treated from butt end should be considered in terms of sapwood proportion as well as effect of treated chemicals.

• Journal of the Korea Furniture Society
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• v.16 no.2 s.30
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• pp.59-65
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• 2005

As physical condition of students improves, there is a need to develop human body-friendly desk and chair for students. In this study, desks and chairs were manufactured with curved veneer lamination under high frequency heating and pressing, using ten wood species such as Japanese red pine, Korean pine, pitch pine, Japanese larch, yellow poplar, black locust, oak, radiata pine, beech, and birch. The performance of these products were evaluated. The results obtained were summarized as follows; With high frequency heating, the turned lamination of veneers with full size sheet ($3{\times}6\;feet$) prepared by rotary lathe peeling was successfully applied for making the members of desk top, leg frames of desk and chair. Bending strengths of desk tops were relatively greater for yellow poplar, black locust and red pine, which were similar to those of beech and birch. Bending strengths of desk legs were classified into greater species group (red pine, yellow poplar, larch) and lower species group (radiata pine, Korean pine, pitch pine). Compressive strengths of chair legs in parallel direction to the lamination were greater in black locust and larch. On the other hand, differences between outer and inner gap at the top and drawer bottom of desk top were rather larger for the laminations of birch and beech, and less for those of yellow poplar and pitch pine, showing greater stability of open drawer space. In results, yellow poplar, larch, pitch pine and red pine showed good appearance and strength properties at the curved veneer lamination. Accordingly, it was believed that these domestic woods were able to substitute for birch which was being imported for the use of veneer-laminates type furniture.