• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.469-476
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• 1999

This study was carried out to investigate the growth and physiological response of shade intolerant and intermediate tree seedlings to enhanced UV-$B_{BE}$(biologically effective UV-B) radiation. The seedlings of Betula platyphylla var. japonica Hara(shade intolerant species) and Fraxinus rhynchophylla Hance(shade intermediate species) were treated with one of the three levels of UV-$B_{BE}$ dosages - ambient UV-$B_{BE}$, ambient+3.2, and ambient+$5.2\;KJ\;m^{-2}day^{-1}$) for 14 weeks in the field condition. Height and root collar diameter growth, leaf area, and biomass production of the seedlings of two species were reduced by enhanced UV-B radiation. Leaf stomatal resistance to water vapor of the F. rhynchophylla seedling was increased by the UV-B increment. The reductions in total chlorophyll and carotenoid were more apparent in the F. rhynchophylla than B. platyphylla seedling. There was no statistically significant changes in the concentration of UV-B absorbing compound($A_{300}$) in the leaves of the two species among the UV-B treatment. However the $A_{300}$ tented to be increased in F. rhynchophylla by enhanced UV-B radiation. These results indicate that the growth and the physiological and biochemical responses between B. platyphylla and F. rhynchophylla were different to enhanced UV-B environment.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.74-88
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• 2021

In the present study, the characteristics and changes in the vegetation of Mt. Cheongryang, Inchon, were examined to identify and determine appropriate ways to restore the health of the urban forest and to preserve its vegetation. The vegetation of the community of Quercus mongolica (Mongolian oak) on Mt. Cheongryang appeared to decrease in response to the control of the wilt disease of oak trees. The communities of Sorbus alnifolia (Korean mountain ash) and Styrax japonicus (Snowbell tree) have increased. Pinus rigida (Pitch Pine) had its overall territory decrease, but the current state of the Pinus rigida (Pitch Pine) was estimated to be stable due to its dominance as a tree layer species. In regards to Robinia pseudoacacia (Black Locust), the urbanized species of Sorbus alnifolia (Korean mountain ash), and Styrax japonicus (Snowbell tree), their areas have increased with the appearance of Magnolia obovate (Whiteleaf Japanese Magnolia). The biodiversity of Mt. Cheongryang has decreased by simplifying species in the tree layer and understory species thereof, and the initial success of species in marginal areas has increased. The absence of potential succession was attributed to the termination of ecological succession; thereby, the current vegetation structure was concluded to be remaining as it is for the time being. Soil texture in the mountain primarily consisted of sandy loam or loamy sand; the pH of the soil was in the range 4.26-4.86, rendering a mean pH of 4.59. The content of organic matter (O.M.) appeared having a distributing range of 2.18-9.60%, rendering a mean value of 4.33%. To promote species diversity, several methods are suggested, such as prevention of soil acidification, selecting nationally-grown trees from moist soil or valleys for afforestation, preventing species appearing due to urbanization or excessive growth, protecting the understory vegetation and species with hygropreference, and managing the forest to maintain a multi-layered vegetation structure.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.365-378
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• 2018

Anthracnose caused by Colletotrichum gloeosporioides, which is one of the major diseases of red dates, causes severe damages in jujube (Zizyphus jujuba Miller) production in Korea. This study was done to evaluate the inhibition of anthracnose occurrence and pathogen growth by the treatment of environment-friendly materials such as a Bordeaux mixture and loess-sulfur mixture and by defense-response signaling in jujube. The in vitro test of the environment-friendly materials and signaling molecules that were routinely applied did not exhibit any antifungal activities against the pathogen for jujube anthracnose. The Bordeaux mixture and loess-sulfur mixture at a two-fold concentration showed inhibition zones that were 16.0 and 20.3 mm in diameter, respectively. In the pathogen inoculation test with detached jujube tree leaves, while treatment with the environment-friendly materials diluted by half showed no inhibition of lesion development, they did show inhibition of lesion development when they were routinely applied to the leaves. In detached jujube fruits inoculated with the pathogen, better suppressive effects by the treatment of the environment-friendly materials were seen in the fruits at a young stage rather than in the ripening stage. The in vivo test with jujube trees in pots showed that the treatment of salicylic acid (1 mM) resulted in the best suppressive effects against lesion development. The results suggest that it is possible to manage the incidence of anthracnose by the treatment of environment-friendly materials such as the Bordeaux and loess-sulfur mixtures and signaling chemicals such as ethephon, hydrogen peroxide, methyl jasmonate, and salicylic acid in jujube trees and fruits. Consequently, these findings suggest that environment-friendly materials and defense response signaling molecules could be used as suitable candidates for sustainable agrochemicals to manage anthracnose in jujube production.

• Journal of Life Science
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• v.20 no.4
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• pp.597-601
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• 2010

Quercus dentata (Thunb. ex Murray) is a major tree found in dry habitats such as limestone areas of Korea. In order to characterize the ecological traits of Q. dentata, we treated Q. dentata saplings under four gradient levels of major environment factors such as light, soil moisture and nutrients for 5 months in a glass house. We then measured and analyzed growth differences among them. Regarding light, aboveground, belowground and plant biomass were highest at a high gradient and lowest at a low one. The root/shoot ratio was highest at the highest light gradient. Regarding moisture, no measured items were significantly affected by the moisture gradient. Regarding nutrients, aboveground, belowground and plant biomass were the highest at a slightly high gradient and the lowest at a gradient lower or higher than this. The root/shoot ratio was not significantly affected by the nutrient gradient. From these results, it was shown that the growth of Q. dentata was more affected by light and nutrients in the environment than moisture.

• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.540-546
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• 2008

Enrichment planting has been used as one of the promising restoration techniques to accelerate the natural restoration process of secondary forests or logged-over forests in Myanmar, The objectives of this study were to examine the growth performances of two commercial species such as Teak (Tectona grandis Linn f.) and Padauk (Pterocarpus macrocarpus Kurz) in response to different canopy opening treatments and to examine the suitability of these species in enrichment planting activities for the restoration of degraded tropical forests in Myanmar. In this study, split plot design was applied, and three levels of canopy openings were experimented. The survival rate and height growth of two species were measured four times with 6 month interval. The root collar diameter (RCD) was also measured in the last assessment. Although the survival rate of seedlings was not significantly different among the three treatments (p>0.05) as well as between two species (p>0.05) for all consecutive measurements, height (p<0.05) and RCD were significantly different (p<0.001) among the treatments, T. grandis seedlings thrived best under complete canopy opening (i.e., 5 m width canopy opening with strip-clear cutting) while P. macrocarpus seedlings under partial canopy opening (without felling of marketable tree species). Because this study is concerned with only for young stage of seedlings, continuous assessment and follow-up tending activities are needed to verify the species suitability and optimum width of canopy opening for enrichment planting activities in restoration of degraded forests of Myanmar.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.150-153
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• 2011

Betulinic acid (BA), a naturally occurring triterpene found in the bark of the white birch tree, has been investigated to induce apoptosis in various cancer cells and animal models. However, there is no report of the chemopreventive effect of BA in cervical cancer cells. Using KB human cervical cancer cells as a model, we currently show that BA decreases cell viability and induces apoptotic cell death. The mechanism of the BA-induced anti-growth response in KB cells is due to the down-regulation of specificity protein 1 (Sp 1) and its downstream targets, myeloid cell leukemia-1(Mcl-1) and survivin. Thus, BA acts as a novel chemopreventive agent through the regulation of Sp1 that is highly expressed in tumors.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.762-770
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• 2014

This study was conducted to elucidate the influence of prohexadione-calcium (Pro-Ca) application on shoot growth and fruit quality in 'Fuji'/M.9 mature apple trees. Pro-Ca was applied at concentrations ranging from 100 to $400mg{\cdot}L^{-1}$ one time at petal fall (PF; 5-10 cm terminal shoot growth) to the whole canopy of the tree, or at 100, 125, $150mg{\cdot}L^{-1}$ concentrations two times, at PF and then 4-8 weeks after PF. Pro-Ca treatment generally reduced mean shoot growth, with its effect being proportional to the application rate. Pro-Ca at $400mg{\cdot}L^{-1}$ significantly reduced the shoot growth by 15-22% compared to the control, while its effect was not significantly different from Pro-Ca $200mg{\cdot}L^{-1}$. Pro-Ca treatments induced higher occurrence of secondary growth compared to the control. Pro-Ca treatment increased the photosynthetic rate by 5-10% relative to the control, and also increased soluble solid concentration and fruit red color. However, fruit weight was significantly reduced by $400mg{\cdot}L^{-1}$ Pro-Ca, which was attributable to the greater secondary growth caused Pro-Ca $400mg{\cdot}L^{-1}$ treatment compared to the control and Pro-Ca $200mg{\cdot}L^{-1}$ treatment.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.234-240
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• 2013

Increasing global $CO_2$ concentration and temperature is leading to the phenomenon of global warming and impacting the growth of plants. In order to determine the effects of global warming on the woody plants of Korea, five woody species, Pinus densiflora (Korea's dominant species), Ginkgo biloba (a commonly used street tree), Quercus glauca (dominant species in sub-tropical forests), Quercus gilva and Abeliophylum distichum (both endangered species), were grown at control (ambient $CO_2$+ambient temperature) and treatment (elevated $CO_2$+elevated temperature) conditions in a glasshouse, and were monitored for their ecological response. Shoot lengths and number of leaves were measured once a month from April to October in 2010, and were again measured in November 2011. Shoot lengths of P. densiflora, G. biloba and Q. glauca were not significantly affected by elevated $CO_2$ and temperature conditions. However. those of Q. gilva and A. distichum were both higher for plants grown under treatment than for those grown under control. The number of leaves of five woody species was not significantly affected by elevated $CO_2$ and temperature. These results indicate that P. densiflora, G. biloba and Q. glauca react more favorably than Q. gilva and A. distichum (each of which are designated as endangered plants) under global warming situations.

• Journal of Korean Society of Forest Science
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• v.106 no.1
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• pp.33-39
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• 2017

This study was carried out in order to closely examine the growth and the physiological response by shading levels of a container seedling of Daphniphyllum macropodum which is known as the species of having shade tolerance in a warm temperature evergreen broad-leaved tree. The shading treatment was regulated with the shading level of full sunlight, and 35%, 55%, 75% of full sunlight. As a result of surveying the height and the root collar diameter growth by the shading level, the height was the highest with 13.2 cm under 35% of shading. The root collar diameter was the highest with 4.99 mm under full sunlight. The organ-based (leaves, shoot and root) dry mass production and the whole dry mass production were higher with 1.38 g, 0.47 g, 0.87 g, 2.72 g, respectively, in order of 35% shading. As for chlorophyll a, b, and the total chlorophyll content, the highest chlorophyll content was shown under 75% of shading with the relatively highest shading level. The ratio of chlorophyll a to chlorophyll b (a/b) was the highest under 35% of shading. The photosynthetic rate, stomatal conductance and water use efficiency were the highest with $12.3{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$, $0.27molH_2O{\cdot}m^{-2}{\cdot}s^{-1}$, $3.53{\mu}molCO_2{\cdot}mmol^{-1}H_2O$, respectively, under 35% of shading. As a result of surveying the whole experiment, D. macropodum grows nicely by maintaining 35% shading.

• Research in Plant Disease
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• v.12 no.2
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• pp.99-102
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• 2006

In 2005, 90 isolates of Colletotrichum gloeosporioides causing persimmons tree anthracnose were obtained from infected twigs and fruits of persimmon trees. Their responses to nine fungicides, consisting of two benzimidazoles (thiophanate-methyl, carbendazim), three ergosterol-biosynthesis inhibitors (difenoconazole, myclobutanil, tebuconazole), and four protective fungicides (propineb, mancozeb, chlothalonil, and dithianon), were investigated with relative mycelial growth index to untreated control on PDA treated with field application rate of each fungicide. At response to carbendazim ($415{\mu}g/ml$) and thiophanate-methyl ($750{\mu}g/ml$), 82% and 78% of isolates showed relative mycelial growth index under 0.1 to untreated control, respectively. All of them did not grow on PDA incorporated with myclobutanil ($40{\mu}g/ml$) and tebuconazole ($75{\mu}g/ml$). Only one isolate (PER 36) grew on PDA amended with difenoconazole ($50{\mu}g/ml$), but its relative mycelial growth index to untreated control was very low with a values of 0.03. They were most sensitive to propineb ($1,500{\mu}g/ml$) among four protective fungicides.