• Journal of the Korean Wood Science and Technology
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• v.8 no.2
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• pp.6-8
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• 1980

Japanese larch veneer, Cryptomeria veneer and japanese cypress veneer were peeled with condition of nose bar pressure at 5%, 10%, 15%, to find the optimum nose bar pressure. 1. Optimum nose bar pressure was 15% in 2mm thickness veneer of japanese larch. 2. Optimum nose bar pressure was 5% in 2mm thickness veneer of Cryptomeria. 3. Optimum nose bar pressure was 15% in 2mm thickness veneer of japanese cypress.

• Asian Journal of Atmospheric Environment
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• v.7 no.2
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• pp.65-71
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• 2013

Japanese cedar (Cryptomeria japonica) pollinosis is the most popular pollinosis in Japan. It has been reported that Cryptomeria japonica pollen allergenic species are suspended as fine particles in the urban atmosphere. These allergenic fine particles are responsible for inducing asthma by breaking into the lower respiratory tract. It has also been found that pollinosis symptoms on the sufferers appear mainly at night-time by the results from epidemiological studies. However, the exact reason for these phenomena is not yet clarified. In this study, the diurnal and nocturnal behaviours of Cryptomeria japonica pollen grains and their allergenic species in the urban area of Saitama city of Kanto Plain were investigated. Airborne pollen grains and allergenic Cry j 1 concentrations in total suspended particulate matter (TSP) were investigated at two sampling sites, a heavy traffic road (roadside site) and at the balcony of the $10^{th}$ floor of the Building of Research and Project of Saitama University (general urban site). The latter sampling site where located about 300 m away from the roadside site was used as a general urban site unaffected by automobile traffic. The airborne pollen counts were measured with a real-time pollen monitor. Cry j 1 particles were collected with two high volume air samplers, and these concentrations were measured by surface plasmon resonance method with a Biacore J system. The diurnal variation of the airborne pollen counts was similar to the trends of temperature and wind speed during the day-time; whereas its tendency with wind speed trend was not observed during the night-time. Airborne pollen counts were lower with northern wind than with southern wind because the pollen comes from the mountainous areas, and the mountains in the south are closer, about half the distance to the northern mountains. It is suggested that the peaks of airborne pollen counts during night-time in the sampling site occurred by transport of pollen grains released during day-time in the mountainous forest areas, located c.a. 100 km away from the sampling site. On the roadside site the allergenic Cry j 1 concentrations were higher than at the general urban site, nevertheless pollen grains counts were lower. These results suggested that worsening of pollinosis symptoms during night-time in urban area was caused by transport of pollen grains during day-time in the mountainous forest areas. Moreover, pollen allergenic species become different morphology from pollen grain at roadside site, and the subsequent pollen grains re-suspension by automobile traffic.

• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.515-522
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• 2023

The aim of this study was to quantitatively evaluate a new stem volume table for estimating the growth, carbon storage, and greenhouse gas (GHG) absorption in Cryptomeria japonica and Chamaecyparis obtusa stands and to provide suggestions for improving the domestic GHG inventory. Carbon storage and GHG absorption were estimated using growing stock data obtained from invariable sub-sample plots between the 6^th and 7^th national forest inventories. We assessed changes in growing stock using the parameters employed by Kozak (1988) and Versions 1 and 2 of the stem volume table. Version 2 has new stem tables for 16 species, including Cryptomeria japonica, which were unavailable in Version 1. Version 2 also includes new data for trees with diameters at breast height equal to or greater than 30 cm. We found greater growing stock values using Version 2 than Version 1 for both stands, and the differences were statistically significant (p<0.001). Applying the new stem volume table increased GHG absorption by 22% for the Cryptomeria japonica stand and 13% for the Chamaecyparis obtusa stand. The growing stock estimation method used in this study should therefore be applied to re-estimate GHG absorptions in the forestry sector to produce accurate statistics for the IPCC guidelines.

• Journal of Microbiology and Biotechnology
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• v.19 no.4
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• pp.391-396
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• 2009

The chemical compositions, and antibacterial and antifungal effects of essential oils extracted from three coniferous species, Pinus densiflora, Cryptomeria japonica, and Chamaecyparis obtusa, were investigated. Gas chromatography mass analysis of the essential oils revealed that the major components and the percentage of each essential oil were 16.66% $\beta$-phellandrene and 14.85% $\alpha$-pinene in P. densiflora; 31.45% kaur-16-ene and 11.06% sabinene in C. japonica; and 18.75% bicyclo [2,2,1] heptan-2-ol and 17.41% 2-carene in Ch. obtusa. The antimicrobial assay by agar disc diffusion method showed that $2.2{\mu}g$ of Ch. obtusa oil inhibited most effectively the growth of Escherichia coli ATCC 33312 and Klebsiella oxytoca ATCC 10031, whereas the C. japonica oil gave weak antimicrobial activity. The minimal inhibitory concentration(MIC) values for bacterial strains were in the range of 5.45-21.8 mg/ml depending on essential oils, but most Gram-negative bacteria were resistant even at 21.8 mg oil/ml. P. densiflora oil showed the most effective antifungal activity and the MIC values for Cryptococcus neoformans B42419 and Candida glabrata YFCC 062CCM 11658 were as low as 0.545 and 2.18 mg/ml, respectively. Cryp. neoformans B42419 was the most sensitive to all essential oils in the range of 0.545-2.18 mg/ml. Our data clearly showed that the essential oils from the three conifers had effective antimicrobial activity, especially against fungi.

• Journal of Applied Biological Chemistry
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• v.50 no.3
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• pp.164-169
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• 2007

Three coniferous essential oils were extracted from Abies koreana, Cryptomeria japonica, and Torreya nucifera by hydrodistillation. The chemical composition of each oil was analyzed by GCMS, and their antimicrobial activities were tested against two bacteria and one yeast strains. Fortyseven compounds were identified from A. koreana oil, 39 from C. japonica, and 59 from T. nucifera. Main components of the essential oils were limonene (23.5%), bornyl acetate (17.9%), ${\alpha}-pinene$ (11.1%), and camphene (10.2%) in A. koreana, kaurene (26.3%), ${\gamma}-eudesmol$ (19.0%), elemol (6.9%), and sabinene (5.1%) in C. japonica, limonene (13.5%), ${\delta}-cadinene$ (10.5%), ${\alpha}-bisabolol$ (10.2%), and ${\alpha}-copaene$ (7.7%) in T. nucifera. Among the three coniferous trees tested, the essential oils of A. koreana exhibited higher and broader antimicrobial activity against the tested organisms than those of C. japonica and T. nucifera.

• Journal of Forest and Environmental Science
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• v.40 no.1
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• pp.9-14
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• 2024

Quantitative evaluation of nutrient status and stoichiometry on the forest floor is a good indicator of litter quality in various vegetation types. This study was conducted to determine the effects of vegetation type on the nutrient concentration and stoichiometry of forest floors at a regional scale. Forest floor samples were collected from four vegetation types of evergreen coniferous forests including Cryptomeria japonica, Chamaecyparis obtusa, evergreen broadleaf, and bamboo spp. forests in southern Korea. The dry weight of the forest floor was higher in the C. japonica and C. obtusa forests than in the evergreen broadleaf and bamboo forests. The mean carbon (C) concentrations of the forest floor were highest in the broadleaf forest, followed by the bamboo forest, C. japonica and C. obtusa forests. Mean nitrogen (N) and phosphorous (P) concentrations in the the coniferous forests were lower than those in the broadleaf and bamboo forests. The mean C:N ratio was the highest in C. obtusa forest (118±25), followed by C. japonica (66±6), evergreen broadleaf (41±1), and bamboo (30±1) forests. However, C:P and N:P ratios were lower in the coniferous forests than in the broadleaf forest indicating that the stoichiometry of the forest floor varies across vegetation types. The C, N, and P stocks on the forest floor were higher in the C. obtusa forest than in the broadleaf or bamboo forests. These results highlight that vegetation type-dependent stoichiometric ratio is an useful indicator for understanding interspecific difference in quality and quantity of the forest floor.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.1
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• pp.67-94
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• 1995

A total of 394 plant species in 74 families planted in home gardens, public building gardens, campuses of elementaiy, middle, and high schools, and universities, recreation areas, city parks, loeal and national ways, and highways from 1.21 local areal in Korea were surveyed- A comparison of the surveyed species to nation-widei.y growing species in those areas were studied. the results obtained were as follows : 1. The ratio of evergreen to deciduous plant species was 38.1:61,9 and that of tree:scrub:vine was 54:40.9:5.1. 2. The ratio of evergreen to deciduous plant species was 27.5:72.5 among total 276 land-scape plant species surveyed in Seoul and Kyongki-do province. The ratios were 32:68 in Kwangwon-do, 36.1:63.9 ill Chungchongbuk-do, 37:61 iii Chungchongnanl-do, 36.4:63.6 in Kyungsangbuk-do, 39.2:60.8 고 Kyungsangaaal-do, 35.7:64.5 in Jollabuk-do, 40.6:59.4 in Jollanam-do, and 43.1 :56.9 in Cheju-do. This results tell that more evergreen species are growing in the southern than in northern region in Korea. 3. Plants with 100% frequency in national planting were 8 species inclubing Forsythia koreana 91-99% were 6 species including Taxus cuspidata, 81-90% were 13 species including Magnolia liilflora, 71-80% were 10 speces including Buxus microphylla val, koreana, 61-70% were 13 species including Thuja occiduntakus, 51-60% were 15 species including Pius thunbergii, 41-50% were 15 species including Kerria japonica, 31-40% were 17 species including Cryptomeria japonica, 21-30% were 28 species including Viturnum awabuki, and below 20% were 267 species including Koelreuteria paniculata. 4 Uppermost north latitude of planting distribution of major temperature species was sum- marized as follows: Although it has been reported that Cryptomeria japonica is possible to grow in areas around -47, the result from this study shows that Cryptomeria japonica grows normally in Choonchun Seoul, Samchuck, and Kwangryeung, etc. , and is possible to grow normally in the areas with approximately -6$^{\circ}C$ in an average temperature in January, where are -2$^{\circ}C$ colder than the reported temperature, but locally warm Phyllostachys bambusoides is distributed to Mt. Kumkang and Mt. Sulak, and also planted in Seoul, Kwangryeung, and Chunchon.

• Journal of Environmental Science International
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• v.31 no.9
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• pp.793-801
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• 2022

This study was carried out to provide basic data for logical forest management by developing a site index curve reflecting the current growth characteristics of Cryptomeria japonica stands in Korea. The height growth model was developed using the Chapman-Richards, Schumacher, Gompertz, and Weibull algebraic difference equations, which are widely used in growth estimation, for data collected from 119 plots through the 7th National Forest Inventory and stand survey. The Chapman-Richards equation, with the highest model fit, was selected as the best equation for the height growth model, and a site index curve was developed using the guide curve method. To compare the developed site index curve with that on the yield table, paired T-tests with a significance level of 5% were performed. The results indicated that there were no significant differences between the site index curve values at all ages, and the p-value was smaller after the reference age than before. Therefore, the site index curve developed through this study reflects the characteristics of the changing growth environment of C. japonica stands and can be used in accordance with the site index curve on the current yield table. Thus, this information can be considered valuable as basic data for reasonable forest management.

• Journal of Korean Society of Forest Science
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• v.69 no.1
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• pp.42-50
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• 1985

The vegetation of common Cryptomeria (Cryptomeria japonica D. Don) stands planted in Chonnam- province was investigated to obtain the fundamental informations for evaluation of suitable site and the improvement of managing method of the Cryptomeria stands in this region. The results investigated were summarized as follows; 1) The growth condition of common Cryptomeria planted 21-25-year-old stands was similar that of same species growing in Akidaken-district in Japan, while the growth condition of 51-58-year-old stands was not so good as that of Japanese. 2) Total number of plant species was 256. The number of floristic composition varied in the range of 42-99- species, which should be mere than those of Japanese. 3) The investigated sites were located in temperate southern part and in subtropic northern part of Korean peninsular. The types of understory vegetation were classified from I to IV class. 4) From the results of high max. possible diversity (H' max), and dominance (1-J') and from the low simple dominance (${\lambda}$) and evenness (J'), It could be concluded that vegetation was relatively in evenness. 5) From the low percent similarity, the specificity among the stands could be evaluated as considerable. 6) After the index of Morista, the 8th stand in Chang sung showed the generalized vegetation, while the 12th stand in Chang hung showed the specialized vegetation. 7) From the low values of Sneath-Sokal distance, the similarity among the stands investigated appeared very high.

• Journal of the Korean Wood Science and Technology
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• v.39 no.4
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• pp.291-302
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• 2011

The study was to investigate whitening and antioxidation effects by determining the tyrosinase inhibition activity, DPPH radical scavenging and superoxide dismutase like activity of essential oils from Cryptomeria japonica and Chamaecyparis obtusa. The aim of the present study was to suggest preliminary data for research whitening and anti-oxidant effects material of C. japonica and C. obtusa essential oils and confirm supplementary worth of natural volatile organic compounds (nVOCs). Essential oils of C. japonica and C. obtusa leaves were extracted by steam distillation method of clevenger type, and nVOCs were extracted by high-temperature reactor for utilizing nVOCs condensates released during drying of C. japonica and C. obtusa at 80, 100, and $120^{\circ}C$ temperature conditions, respectively. In the activity of whitening and antioxidation, C. japonica oil was more effective than C. obtusa oil. nVOCs of C. japonica and C. obtusa showed highly activity of tyrosinase inhibitory at higher temperature. Antioxidation activity only shown on nVOCs of C. japonica produced at $120^{\circ}C$.