• Journal of Plant Biotechnology
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• v.50
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• pp.200-206
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• 2023

Although softwoods are widely distributed in Korea and used in various industries, studies are limited and comparative research on softwoods has been overlooked. Therefore, in this study, the physiological activity of four species of softwoods found in Korea was quantified. Needles and cones of Pinus densiflora, Chamaecyparis obtusa, Cryptomeria japonica, and Abies koreana were collected, and material was extracted using 70% methanol. We quantified the following physiological traits: total phenol and flavonoid content, antioxidant activity (DPPH, TEAC, FRAP), and inhibitory activity of the enzymes α-glucosidase, elastase, and tyrosinase. Total phenol and flavonoid contents and antioxidant activities were high in Chamaecyparis obtusa and Cryptomeria japonica, and α-glucosidase inhibition activity was highest in the leaves of Chamaecyparis obtusa. Elastase inhibitory activity was high in the leaves and cones of Pinus densiflora and the cones of Abies koreana, and tyrosinase inhibitory activity was highest in the leaves of Pinus densiflora. In Korea, softwoods are planted extensively on roadsides and as windbreaks, and they are highly competitive in supplying raw materials since they are pruned every year. Based on the results of this study, softwoods are considered suitable for use in healthcare products, diabetes products, wrinkles, and whitening cosmetics.

• Fashion & Textile Research Journal
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• v.19 no.4
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• pp.486-492
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• 2017

This study finds surface color and functions of natural dyeing from Chamaecyparis obtusa leaves which help cure skin problems such as atopic dermatitis. This study also seeks to find dyeing properties and functions of natural colorants derived from Chamaecyparis obtusa and Rubia tinctorum on silk. Dyeing properties and functions are compared between silks dyed with Chamaecyparis obtusa and silks composite-dyed with Chamaecyparis obtusa and Rubia tinctorum. The comparison examines the feasibility of developing healthy and high functional fabrics and wellness of fashion merchandises. Silk dyeing with Chamaecyparis obtuse leaves yields yellow and double coloring from Chamaecyparis obtusa; however, Rubia tinctorum yields yellow/red on silks. Silks dyed with Chamaecyparis obtusa and silks composite-dyed with Chamaecyparis obtusa and Rubia tinctorum show a high level on dry cleaning, ultraviolet protection and deodorization. Especially, the dyed silks from leaves of Chamaecyparis obtusa show a 99.7% antimicrobial effect against staphylococcus aureus ATCC 653B. Silks composite-dyed with Chamaecyparis obtusa and Rubia tinctorum are better known for medicinal herb for dermatitis, and natural colorant, Rubia tinctorum does not improve significantly functions compared with silks dyed with Chamaecyparis obtusa. However, the dyeing properties improve by composite dyeing. This implies that ways to maximize effects of tie-dyeing technique could be developed.

• Journal of Convergence for Information Technology
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• v.12 no.5
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• pp.126-132
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• 2022

Wood Plastic Composite(WPC) has been mostly used for outdoor purposes such as deck materials and trails so far. In this study, WPC panels with improved antibacterial properties, total volatile organic compound emissions (TVOC), and flame retardant were manufactured to use Wood Plastic Compound as interior materials for indoor use. WPC compound was prepared by mixing Chamaecyparis obtusa wood flour with high density polyethylene(HDPE). The prepared WPC compound exhibited excellent antibacterial and antifungal properties, and the total volatile organic compound emission(TVOC) was 0.062 mg/m2·h. The WPC panel(303mm×606mm×10mm) manufactured by a twin screw extruder with the manufactured compound achieved the flame retardant grade 2 standard of KS F 2271.

• 한국양묘협회지
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• s.5
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• pp.35-40
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• 1977

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.495-501
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• 2006

This study was conducted to investigate the effects of thinning on soil properties and seed productivity in the 25-year-old Cryptomeria japonica and 30-year-old Chamaecyparis obtusa seed orchards in which thinning had been performed 4 years prior to the study. To this end, soil properties, cone and seed characteristics, seed production (kg/ha), and nutrient contents in seeds and cones were studied by 4 different thinning intensities (0, 20, 40, and 60%). Soil properties were not significantly different between the two orchards. Meanwhile, electric conductivity, total nitrogen, and $K^+$ concentration in the soil of C. obtusa seed orchard were significantly different among 4 different thinning intensities (p<0.05), while only $Ca^{2+}$ concentration in the C. japonica seed orchard was different (p<0.05). In the C. obtusa seed orchard, cone productivity increased with the increase of thinning intensities (p<0.05), whereas that in the C. japonica seed orchard did not show any significant differences. Both of the two seed orchards showed a tendency that seeds become bigger and heavier with the increase of thinning intensities, but any significant differences were not found. Seed production (kg/ha) in the C. obtusa seed orchard significantly increased with the increase of thinning intensities, while that of the C. japonica seed orchard decreased. Nutrient contents in seeds and cones did not show any significant differences among different thinning intensities in both of the two seed orchards.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.169-178
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• 2020

This study aimed to compare the organic carbon stocks of Cryptomeria japonica and Chamaecyparis obtusa stands established under a similar-site environmental condition in South Korea. C. japonica and C. obtusa stands adjacent to each other from 13 representative regions were chosen to evaluate the carbon stocks of tree biomass, forest floor, and mineral soils. Mean stand ages were 45 years for C. japonica and 43 years for C. obtusa, respectively. Tree density was significantly lower in C. japonica (989 tree ha^-1) than in C. obtusa (1,223 tree ha^-1) stands, whereas diameter at breast height and dominant tree height values were significantly higher in C. japonica (27.4 cm and 20.4 m, respectively), compared with C. obtusa (23.9 cm and 17.9 m, respectively) stands. The total carbon stocks of tree biomass were linearly related with stand basal area (C. japonica: r² = 0.82; C. obtusa: r²= 0.92; P< 0.05), whereas stand density and site index were not correlated with the carbon stocks of tree biomass (P > 0.05). The carbon stocks of aboveground tree biomass were significantly higher in C. obtusa (117.7 Mg C ha^-1), compared with C. japonica (95.5 Mg C ha^-1) stands, whereas carbon concentration and stocks of the forest floor and mineral soil layers were insignificantly different between the C. japonica and C. obtusa stands. The results indicated that trees in C. obtusa stands sequestrated more carbon dioxide, compared with C. japonica stands, whereas carbon stocks in the forest floor and mineral soil layers were unaffected by stand development processes of the different tree species.

• Journal of agriculture & life science
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• v.44 no.3
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• pp.31-40
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• 2010

This study was carried out to offer a basis data for conservation and application of effective management of Camellia japonica stand in Hakdong, Geoje Island. Field survey was conducted at C. japonica stand, mixed stand, Chamaecyparis obtusa plantation, and Pinus thunbergii stand. Importance value of C. japonica at tree layer was highest in C. japonica stand and mixed stand, and that of C. obtusa and P. thunbergii were highest in C. obtusa plantation and P. thunbergii stand, respectively. At subtree layer, C. japonica, Callicarpa dichotoma, Neolitses serices, and Styrax japonica had the highest importance value in C. japonica stand, mixed stand, C. obtusa plantation, and P. thunbergii stand, respectively. The species diversity ranged from 0.121 to 1.589 in C. japonica stand, 0.543 to 1.540 in mixed stand, 0.276 to 1.321 in C. obtusa plantation, and 0.764 to 1.523 in P. thunbergii stand, respectively. Soil pH was 5.72 in C. japonica stand, 5.26 in mixed stand, 5.21 in C. obtusa plantation, and 5.32 in P. thunbergii stand. The content of organic matter and total N were 5.77, 0.48% in C. japonica stand, 4.41, 0.30% in mixed stand, 3.28, 0.33% in C. obtusa plantation, and 5.32, 0.28% in P. thunbergii stand.

• 한국양묘협회지
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• s.8
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• pp.35-35
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• 1980

• Landscaping Tree
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• s.132
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• pp.26-29
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• 2013

• 한국양묘협회지
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• s.13
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• pp.22-26
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• 1985