• Journal of agriculture & life science
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• v.45 no.3
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• pp.53-58
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• 2011

To develop an efficient micropropagation technique for Vitex negundo var. insica, which is known as aromatic and medicinal tree, the effects of various plant growth regulators (PGRs) on in vitro shoot proliferation and rooting were evaluated using the newly-developed shoots of a 3-year-old tree. Multiple shoot induction was achieved effectively on WPM (woody plant medium) supplemented with 0.5-2.0 mg/L BA, and the highest shoot number (7.9/explant) was obtained at the concentration of 1.0 mg/L BA. Typically 1 or 2 superior shoots (about 3.4 cm) were induced on hormone-free WPM. Combined treatment of BA 2.0 + GA 0.5 mg/L appeared to effective on shoot proliferation and rooting. Plant growth regulators added in shoot proliferation medium had strong impact on subsequent rooting as well. Overall, shoots induced by BA treatment resulted in high rooting rates while the effect was reduced gradually by ascending BA levels. TDZ of low concentration also revealed a similar tendency as BA, but the rooting ability was strongly inhibited at the concentration of 0.5 mg/L, and rooting was never observed at the concentrations higher than 0.5 mg/L. Combined treatment of BA and IBA had positive influence in both shoot proliferation and rooting. These results suggest that Vitex negundo var. insica could be effectively micropropagated via axillary bud cultures.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.725-733
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• 2001

In this study, the relationship between growth factors for Pinus densiflora stands in Anmyun-Island was analyzed and dynamic growth model was prepared. A total of 96 sample plots was investigated in which dbh and height of individual trees were measured. From these plot data, quadratic mean dbh, mean height, dominant tree height, stem number per ha, basal area per ha and volume per ha were estimated. Several regression equations between growth factors were derived using NLIN and REG procedure of SAS. And dynamic growth model, in which the equations were interactively linked, was prepared for the prediction of stand growth and yield under different management regime. The predictions of dynamic growth model were found to be coincided with general growth principles. The dynamic growth model was considered as adequate for predicting growth and yield of Pinus densiflora stand in Anmyun-Island. In practice, the dynamic growth model can be applied for predicting the growth and development of stand for various forest treatments and for decision-making in forest management.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.45-48
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• 1980

Multivariate analysis methods were used to examine the relationships between top and bottom growth variables of hybrid poplars after coppicing and to discriminate between clones in coppice growth potential. Strong and linear relationship was exhibited between top and bottom growth variables. Clone 5328 was different from the other clones and the best among the clones in coppice growth potential.

• Journal of Korean Society of Forest Science
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• v.2 no.1
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• pp.41-43
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• 1962

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.349-356
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• 2019

This study examines the effect of thinning in terms of changes in the growth characteristics of Chamaecyparis obtusa stands after they were thinned with varying intensity in Gochang, North Jeolla Province, Korea. Thinning was carried out in 2000 on Chamaecyparis obtusa stands (22 years old), and the stands were categorized in terms of the thinning intensity in the experiment: very heavy, heavy, medium, light, and control. The results of monitoring up to 2018 revealed that the diameter at breast height and the growth rate of individual trees after thinning had a positive correlation with the thinning intensity, whereas the stand volume showed a negative correlation. The height to diameter (H/D) ratio decreased by up to 70-80 due to the increased diameter at breast height after thinning and thereby resulted in better quality. The relative yield index right after the first thinning was between 0.75 and 0.95, which suggests the best timing for the first thinning had been missed. This study's findings are expected to serve as a basic reference in establishing the thinning system for Chamaecyparis obtusa forests.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.310-317
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• 2008

Although aerial LiDAR had been launched commercially several years ago, it is still difficult to study data acquisition conditions and effects with various datasets because of its acquisition cost. Thus, this research was performed to study data acquisition conditions and effects with virtually various datasets. For this research, 3D tree models and forest stand models were built to represent graded tree sizes and tree plantation densities. Also, a variable aerial LiDAR acquisition model was developed. Then, through controlling flight height parameter, one of the data acquisition parameters, virtual datasets were collected for various data acquisition densities. From those datasets, forest canopy volumes and maximum tree heights were estimated and the estimated results were compared. As the results, the estimated is getting closer to the expected during the data acquisition density increase. This research would be helpful to perform further studios on relations between forest inventory accuracy and LiDAR cost.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.37-47
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• 2018

The objective of this study was to analyze the influences of forest management activity on the diameter distribution of Larix kaempferi Carriere stands in South Korea. We used 232 managed stands data, 47 unmanaged stands data of National Forest Inventory for this study. We employed the Weibull distribution function for estimating diameter based on percentiles and parameter recovery method. The results revealed that the average diameter breast height movements and growth of tree in the managed stands higher than the unmanaged stands according to the scenario: age, site index, and tree density change. The finding shows the percentage of the total amount of large class diameter was also high in the managed stands. The results of this study could be apply for the estimation of multi-products of timbers per diameter classes and stand structure development for Larix kaempferi Carriere stands in South Korea.

• Journal of agriculture & life science
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• v.43 no.3
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• pp.7-14
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• 2009

Some results of the 5th Korean National Forest Inventory Program measured in 2007 were used to analyze annual diameter growth characteristics for major tree species distributed in Chungnam province. A total of 717 sample trees from 49 plots distributed in Chungnam province were measured and analyzed for annual diameter growth characteristics. As stand age and stand density increased, annual diameter growth rates for major species tended to decrease. The species of Prunus sargentii(2.14mm/yr) showed the best annual diameter growth rates and the others are Quercus serrata(2.10mm/yr), Pinus thunbergii(2.03mm/yr), Pinus densiflora(1.91mm/yr), and Castanea crenata(1.90mm/yr) in order. This information could be very useful to understand annual diameter growth characteristics for major species distributed in Chungnam province.

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.300-312
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• 2020

The growing stocks of young forests that are less than10 years of age have been excluded from the Korean forest resource statistics, despite the existence of standing trees; however, sustainable forest management and carbon removals in the forestry section require complete information regarding forest resources. This study developed a method to estimate the growing stocks for young forests from National Forest Inventory (NFI) data. After reviewing previous research on growth characteristics for young forests, we conducted stem analysis of major species, and examined stand characteristics by site index, based on real yield tables. Our statistical analysis results showed that there were few standing trees with diameters at breast height (DBH) above 6 cm in young stands, and that it would have taken 12 years, on average, to reach 6 cm DBH. This suggests that mean tree height by diameter should be assessed at the root, in order to assess growing stocks for young stands through the NFI. Moreover, the database system should be improved to differentiate tree species, since diverse shrubs, including trees, have been surveyed.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.212-217
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• 2011

A photoautotrophic micropropagation methodology in liquid culture medium has a number of advantages for large-scale propagation of plants. This paper describes an improved system for the mass propagation via somatic embryogenesis of the medicinal plant Kalopanax septemlobus Nakai. Somatic embryo-derived young plantlets of K. septemlobus were cultured either under heterotrophic conditions with sucrose on half-strength MS medium with $30gL^{-1}$ sucrose, under heterotrophic conditions without sucrose, or under photoautotrophic conditions (MS liquid medium without sucrose under forced aeration) for four weeks before transferring the plantlets for acclimatization. Plantlets grown under photoautotrophic conditions had more leaves, higher chlorophyll content, a higher net photosynthetic rate (NPR), and a higher survival rate. The results indicate that the photoautotrophic conditions with a forced ventilation system are effective in enhancing the growth of plantlets and the rate of net photosynthesis. The plantlets grown under photoautotrophic conditions had a high survival rate (92%) upon ex vitro transplantation. Our study shows that autotrophically produced plantlets acclimatize better and sooner upon ex vitro transplantation than conventionally cultured plants.