• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.13-22
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• 2007

This study was carried out to scrutinize possibility of manufacturing pitch pine (Pinus rigida) glued laminated timber in order to add values of pitch pine trees. Also, it was investigated to improve bending performance of pitch pine glulam. Pitch pine was imported as one of major plantation species in Korean peninsula. Machine stress rated grades of pitch pine lumber mostly ranged between E7 and E9. which grades were more or less inferior to producing high quality glulam. However, the adhesive properties between pitch pine and pitch pine, and between pitch pine and Japanese larch (Larix kaempferi Carr.), such as shear bond strength, wood failure rate and de-lamination rate of bonded layer submerged in cold and boiling water, were higher than Korean Standard criteria. These properties are essential for manufacturing glulam with single species or multiple species. The modulus of rupture (MOR) of pitch pine glulam exceeded the criterion of Korean Standard for glulam strength grade but modulus of elasticity (MOE) was lower than the criterion. On the other hand, the bending performances (MOR and MOE) were improved 20 percent by mixing with Japanese larch laminar. It is effective to arrange higher quality Japanese larch laminar at the outer layer of glulam for improving bending performances. In conclusion, it is possible to use low quality pitch pine as laminar of structural glulam for adding values of pitch pine.

• Korean journal of applied entomology
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• v.29 no.1
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• pp.14-19
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• 1990

Nematodes and insects associated with dead trees were surveyed on the 238 dead trees belonging to 19 tree species in Pusan, Gyeongnam, Gyeongbuk, Chunnam, and Chonbuk provinces from April to September of 1989. Pine wood nematode, Bursaphelenchus xylophilus was found only in Pusan but B. mucronatus was collected at Chinju and Chinhae. The 13 nematode species in 9 genera were identified. Out of them, Diplogasteroides dimidius, Rhabdontolaimus adephagus, R. janae, Mikoletzkya diluta, M. ruminis, M. langcaudaa, Parasitorhabditis hylurgi, Panagrolaimus concolor, Panagrodontus dentatus, Prothalonema intermedium, and marcrolaimus canadensis were recorded for the first time in Korea. Insects collected from dead trees were 5 orders, 9 families, 25 genera, and 27 species. of them, the Coleoptera were the most collected insects by the 3 families, 19 genera and 22 species. The Scolytidae were 12 species in 10 genera. Hypothenemus eruditus was firstly collected from Campylotropis macrocarpa, Lespedeza maximowizi, Forsythia ovata, Meliosma oldhami, Securinega suffruticosa, Broussonetia kazinoki, and Cornus walteri. The maximum number of pine wood nematode was separated from the abdomen of Monchamus alternatus, the pine woodnematode vector. The maximum number of nematodes per an adult of M. alternatus was 127,535, minimum 2,616, and average 42,817.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.5
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• pp.35-53
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• 2021

A field survey was carried out targeting 59 pine wilt disease control areas distributed in Andong, and the ecological characteristics of the areas affected by pine wilt disease were analyzed using vegetation information, ecological information, and land use information. Vegetation characteristics of Pine wilt disease affected forest area showed a 3-layer vegetation structure, high percentage of accidental occurrence species (37%) and secondary vegetation species (59.6%), appearing 12 taxa naturalized plants and 3 taxa ecosystem disturbance organisms designated by the Ministry of Environment. Ecological information of Pine wilt affected area showed frequent occurrence of water stress in south and west slopes, low lying grounds in mountains, and in well-drained soils. Also, surrounding the area has been used as roads, tombs, and cultivation where intensive human activities were the cause of disturbance and stress to the pine forest. It was analyzed that the pine forest in Andong city suffered extensive damage due to the onset of pine wilt disease while the pine trees were weakened due to continuous human activities. Conclusively, the spread and onset of pine wilt disease are worsened by artificial factors than natural environmental conditions.

• 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 Korean Professional Engineers Association
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• v.42 no.5
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• pp.50-54
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• 2009

The new method to improve pine-fungi activity are needed by customed forest tending. Fungi is essencial for human life. Pine-mushroom (Trichroma matsutake)products are related to fungi activity. These are improved by customed forest tending. For example, species arrangement, thinning ratio, light control, water supply etc.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.258-266
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• 2023

Pine wilt disease is caused by the pine wood nematode (Bursaphelenchus xylophilus) and has killed many pine trees in Europe and Northeast Asia, including South Korea. Resistance to pine wilt disease varies among species. Previous studies were mostly conducted in nature or greenhouses and only a few in test fields. In this study, seedlings of six pine species (Pinus thunbergii, P. koraiensis, P. densiflora, P. parviflora, P. rigida × P. taeda, and P. strobus) were artificially inoculated by pine wood nematodes in the test field. The Wilt Index was measured every 2 weeks after inoculation in addition to the mortality rate, detection rate, and pine wood nematode concentration measurement after 24 weeks. The pine wilt disease mortality rates were P. thunbergii (80%), P. koraiensis (77.8%), P. densiflora (62.5%), and P. parviflora (22.0%), and both P. rigida × P. taeda and P. strobus survived. The pine nematode detection rates were the same among the species except for P. rigida × P. taeda pine (22.2%). High Wilt-Index values were obtained for P. thunbergii, P. koraiensis, and P. densiflora, which had mortality rates higher than the other species. Furthermore, there were no significant differences in the Wilt Indexes between P. parviflora, P. rigida × P. taeda, P. strobus, and the control group. Statistically, P. thunbergii and P. koraiensis showed high susceptibility to pine wilt disease, P. densiflora and P. parviflora showed moderate susceptibility, and P. rigida × P. taeda and P. strobus showed apparent resistance. These results provide basic data for pine wood nematode resistance breeding or as evidence of the need for afforestation of P. rigida × P. taeda and P. strobus.

• The Plant Pathology Journal
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• v.24 no.2
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• pp.112-117
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• 2008

Pre-infection behavior of Fusarium circinatum on stems of pine species was investigated with scanning electron microscopy. Two-year-old stems of Pinus densiflora and p. rigida were inoculated with the fungal conidial suspension and subjected to $25^{\circ}C$ for up to 16 hr. Most microconidia germinated 12 hr after inoculation on pine stems. Conidia produced germ tubes from either one or both ends of microconidia. Germ tubes grew over the stem surface and appeared to enter host tissues through natural openings on pine stems. Surface cracks in the cork were entrance sites of germ tubes of F. circinatum. In addition, host cell wall cracks were often found at the tip of germ tubes. The cuticle appeared to be eroded either at the tip of germ tubes or around germlings. Germ tubes also produced appressoria-like structures, exhibiting swollen tips of germ tubes on the stem surface. There seems to be no significant differences in the pre-infection behavior of F. circinatum on stems between the two pine 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 Korean Society of Forest Science
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• v.85 no.2
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• pp.244-250
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• 1996

The objectives of this paper were to study the existence of resistant substance to pine gall midge from needles of Pinus densiflora, P. thunbergii, P. virginiana, and P. thunbergii${\times}$P. virginiana, and also to investigat whether terpenoids, fragrant substance contained in those species seduce or evade imago of pine gall midge to oviposit. Also, terpenoids and phenolic compounds were bioassayed on larva. The results are follows. Adults of pine gall midge oviposited indiscriminately all investigated pine species, while gall formation rate by pine gall midge showed 0% in Pinus virginiana, 9% in P. thunbergii${\times}$P. virginiana, 22% in P. thunbergii. It is suggested that young larvae is necrotized by resistant substance in the needles of P. virginiana. This results might mean that fragrant substance, terpenoids, extracted from pine species is not seducible or evadable substance. Larvae of pine gall midge placed on terpenoid and resin were not necrotized. The necrosis rate of larvae of pine gall midge cultivated in the solution of phenolic compounds extracted from needles of P. virginiana, salicylic acid and chitinase showed 89, 92, and 86% respectively. And necrosis rate was 56 and 59% in phenolic compounds extracted from P. densiflora and gallic acid respectively. So, it is postulated that phenolic compounds contained in needles of P. virginiana, salicylic acid and chitinase are resistant substance to pine gall midge.

• Journal of the Korea Furniture Society
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• v.19 no.6
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• pp.460-465
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• 2008

When wood is exposed to natural weathering and UV radiation discoloration progresses. The color variation of heat-treated wood was investigated. Four domestic species were selected and heat-treated at $220^{\circ}C$ and naturally weathered for 42 days. Their colors were measured with a portable colorimeter. The color variations were different between species. The Korean red pine specimens were highly discolored by the natural weathering even though they were heat-treated. In contrast to Korean red pine, Korean pine is less discolored. The maximum color difference of larch was lower than Korean red pine. All specimens of birch exceeded the color difference criterion of 15 after 25 hours with the maximum of 28.