• The Korean Journal of Ecology
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• v.17 no.1
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• pp.11-22
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• 1994

The understory vegetation of a Chamaecyparis obtusa plantation is relatively sparse at a valley in Sangkwan-my6n, Wanju-gun, Chiinbuk, Korea, and that of the pure C. obtusa plantation is more sparse than in the C, obtusa-Larix leptolepis plantation. In order to investigate the causes of this difference, this study was carried out both in the field and in the laboratory. Total of 109 taxa, comprising 90 genera and 53 families, were identified in the plantation. But the average number of species above 10% frequency was only 27, and both the number of species and plants per quadrat in the pure C. obtusa plantation were lower than those in the C, obtusa-L. leptolepis plantation. Light intensity, soil pH, and the difference of soil minerals were supposed to be parts of the causes. Soils, litter extracts of C. obtusa and L. leptolepis, and leachates collected by vermiculite beneath C. obtusa canopy for 1 year were tested for the effect on germination and seedling growth of both inside species and outside species in the laboratory. Germination and seedling growth of outside species were more suppressed than those of inside species. Therefore it was found that allelopathic effect of C. obtusa would be responsible for the sparse understory vegetation in the C. oblusa plantation.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.447-452
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• 2005

The characters of Chamaecyparis obtusa community extended around the Mt. Gyeryoung in Geoje-cik were investigated for several ecological parameters and the results can be summarized as fellows. Chamaecyparis obtusa is prevailing in the plantation area, whereas Pinus densiflora and Quercus mongolica are prevailing in its outskirts. Plant biomass and net production which estimated from degree of green naturality and Miami's model were much higher in the plantation than those of the natural forest. However, the mean species diversity of plantation was lower than that of natural populations. In stratification of investigated areas, overstory tree layer was dominant in the zone of plantation and dominant layers in the natural forest were understory tree layer, shrub, and herb.

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.117-126
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• 1997

In fast grown softwood, there are very large changes in material properties going outward from the pith to bark such as anatomical, physical and mechanical characteristics. Some of variations in anatomical properties with annual ring were then examined from Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa, which are major softwoods of plantation in Korea. The large variations of annual ring width during young age of tree tended to stabilize after 25year through the transitional period in 17~23year. The ring density was 1.5~2.4 in 1~10year period, and 3.5~6.3 in 30~35year period, in which juvenile and mature wood were certainly assumed to be formed, respectively. Variations of tracheid length showed functional relationships with annual rings as logarithm. Demarcation between juvenile wood and mature wood could be 16~19year, which was determined from increase rate of tracheid length of 0.2%. Cell wall thickness increased with increase of annual ring even though large variations were observed as well. Variations of cell wall thickness within species were pronounced in latewood than earlywood. The increase of cell wall thickness from juvenile wood to mature wood was predominant in Larix leptolepis as 2.0times, and least in Chamaecyparis obtusa as 1.1 times. Cell diameters showed trends of increase during young age of 1~15year, and consistent afterward. The variations of cell diameter between radial and tangential direction were greater in latewood, and most pronounced in Chamaecyparis obtusa.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.393-407
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• 1991

The vegetation structure within Chamaecyparis obtusa plantation was analyzed for the purpose of applying the effective forestation method for Chmaecyparis obtusa plantation, tending and regeneration in the southern districts of korea. The results were as follows ; 1. The importance percentage was high in the order of Eurya japonica, Rhus verniciflua, Chamaecyparis obtusa, Lindera erythrocarpa, Carpinus laxiflora, Styrax japonica, Viburnum dilatatum, Zanthoxylum piperitum and Smilax china among the vegetation of Chamaecyparis obtusa. Importance percentage of natural seedling of Chamaecyparis obtusa was high in lower story but gradually decreased in middle story. 2. The basal area of upper trees had a negative correlation with the density of natural seedlings in the middle and lower story, and it represents that the basal area of upper trees had some effect on the density of natural seedlings within understories. 3. The rate of the A and B class by Raunkiaer's frequency was higher in the vegetation of middle story than that of lower story. 4. By Morisita's index, the species of Chamaecyparis obtusa, Rhus verniciflua, Lindera erythrocarpa, Smilax china. Callicarpa japonica and Lindera obtusiloba were randomly distributed at lower story, but they were aggregatively distributed at middle story. At all of middle and lower story, Eurya japonica and Viburum dilatatum were randomly distributed, and Carpinus laxiflora, Zanthoxylum piperitum and Picrasma quassioides were aggregatively distributed. 5. The number of appearance species and the value of species diversity in western survey area were more than that of eastern survey area. 6. The value of species diversity at lower story was higher than that of middle story, and it represents that the number of individuals of appearance species was composed more even at lover story than middle story. 7. According to cluster analysis by similarity index, the survey areas were separated from inland and seacoast districts. 8. Judging from each stories ordination analysis by dissimilarity index, the vegetation was separated from lower and middle story, and the vegetation of lower story was more progressed succession stage than that of middle story. 9. In Chamaecyparis obtusa stands, Eurya japonica had a positive correlation with Sorbus alnifolia, Hex macropoda. Ficus erecta and Trachelospermum asiaticum, but it had a negative correlation with Zanthoxylum piperitum, Carpinus laxiflora and Parthenocissus tricuspidata. 10. In estimation of the productivity of Chamaecyparis obtusa stands, the value of SC (Conic surface) and VP (Parabolic volume) for upper trees was 94.5% and 99.63%, respectively and SC and VP of middle story was 5.49% and 0.37%, respectively. In the species of middle story, material productivity was high in order of Eurya japonica. Lindera eryhrocarpa, Rhus verniciflua. Carpinus laxiflora and Styrax japonica.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2005.10a
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• pp.106-108
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• 2005

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.375-382
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• 2014

The objective of this study was to investigate suitable plantation site for planted Chamaecyparis obtusa seedlings from the analysis of regional early growth performances. Two years old C. obtusa seedlings were planted with the density of $3,900seedlings{\cdot}ha^{-1}$ in late March, 2011 at Haeman and Jangseong, Jeollanamdo. In each study site, three plots ($400m^2$ per plot) were established and root collar diameter (mm) and tree height (cm) of each C. obtusa were measured in April, 2011 and October from 2011 to 2013. We also analyzed soil physical and chemical properties of sites and compartmental nitrogen and phosphorus concentrations of C. obtusa. Although the concentrations of soil nitrogen, organic matter, and C.E.C. at Haenam site were higher than those at Jangseong site, early growth performances of planted C. obtusa at Jangseong site were significantly better than those at Haenam site. The reasons for these results were probably related to deep available soil depth at Jangseong site and relatively low annual precipitation and sea wind at Haenam site, which was adjacent to the sea. The compartmental nitrogen and phosphorus concentrations of C. obtusa was in the order of needles > current twigs > fine root > stem and branches root above 2 mm in diameter. The phosphorus concentration of needles at Haenam site was significantly higher than that at Jangseong site. The results of this study might be useful for the selection of suitable plantation site for C. obtusa.

• 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.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.317-323
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• 2012

This study was performed in order to explore the growth characteristics by growing stage in the containerized seedling and the bare root seedling of Chamaecyparis obtusa Sieb. et Zucc., which is the major plantation species of Korean southland. The height growth of 1-year-old bare root seedlings was better than containerized seedlings, which grew in the containers with capacity of 31.2 mL and 300 mL. The root collar diameter growth was the best in the containerized seedlings of container with 300 mL. The 2-year-old bare root seedlings were surveyed to be better in the height and root collar diameter growth than the containerized seedlings of container with 300 mL. In the comparison of dry mass production, it was the highest in 32 mL containerized seedlings as for 1-year-old above ground and in 300 mL containerized seedlings as for below-ground and total dry mass production. In case of 2-year-old seedlings, it was indicated to be high in bare root seedling as for the part above ground and in dry mass production of the containerized seedling as for the part below ground. In the comparison on root morphological traits of seedlings such as the total root length, the root project area, the root surface area, the average diameter in root, and the root volume, all of 1 and 2-year -old containerized seedlings showed the higher growth than the bare root seedlings except the average diameter in root. Synthesizing the results of this experiment, the containerized seedlings are relatively excellent in root development compared to bare root seedlings in the process of producing seedlings of C. obtusa, thereby being judged to have grown into excellent seedlings.

• Journal of Korea Foresty Energy
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• v.22 no.1
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• pp.49-57
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• 2003

This study was carried out with Urich II method for estimating the aboveground biomass of 30 years old Chamaecypris obtuse plantation in Jinhae, Cyeongnam province, in order to solve problems of exhaustion of many time and manpower in field survey for estimating biomass of stands. The results were summarize as follows; Total aboveground biomass production of stands was 137.3ton/ha, which was 71.8% of stem, 15.4% of branch and 12.8% of leaf. Foliage biomass of stands was maximized on the 9.2~11.2m of total height. The ratio of biomass for each part of tree in Chamaecypris obtusa plantation was in order of, stem, branch and leaf in dominant and co-dominant tree, and was stem, leaf and branch in recessive tree. drying ratio by components were ranged 47.3~49.2% of stem, 48.8~52.9% of branch, 39.2~40.8 of leaf and 0.78%~0.89% of died branch. Specific gravity by sample tree was 0.49~0.53 range and there was not significantly different among sample tree.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.24-24
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• 2018

Degraded plantation forests are increasing because of unfavorable forestry conditions prevailing in Japan, including falling timber prices, increasing operational costs, and aging and declining forestry workforce. To remedy this situation, appropriate management strategy is required. This study introduces the challenges of Odai Town, Mie Prefecture that employed a new management strategy by evaluating site suitability for conifer forests and that proposes a new forest management regime of planting deciduous trees in unsuitable sites. The site suitability for conifer forests was evaluated from two aspects: the natural site conditions and the relationship among site conditions, growth, and damage by Anaglyptus subfasciatus Pic. in Cryptomeria japonica D. Don and Chamaecyparis obtusa Sieb. Et Zucc. forests. By analyzing the relationship among site conditions, growth, and insect damage based on field data obtained in plantation forests, growth evaluation and insect damage evaluation maps were developed. Based on the natural forest investigation, natural site condition maps for C. japonica and C. obtusa were established. Furthermore, by integrating these evaluation maps with the forest road maps showing the accessibility to the forest, the forest management regime for the whole plantation area of Odai Town was established. The forest management regime map indicates the sites suitable for forestry: suitable for long-rotation, short-rotation, and potential sites for short-rotation. The sites unsuitable for forestry were considered to be more suitable for broadleaved forests. Clear-cutting was conducted in a small area and different seral stage saplings (approximately 20 deciduous tree species) suitable to the site conditions were planted in an area of $80-120m^2$ protected by deer-fences. This might establish a forest composed of many species with a multilayer vertical forest structure in a short period. The planted saplings were distributed neither randomly nor uniformly to reflect the natural distribution of trees in the forest. A challenge to develop new products using the deciduous trees has started, such as wood chips for preparing smoked food, essential oil, and deodorizer. As these challenges have just begun, their effects on enhancing sustainable resource management are still being monitored. Even with the challenges, this regime can be of high value as a management strategy to remedy the situation of expansion of degraded forests in Japan.