• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.722-728
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• 2012

Climate change affects all biological processes in terrestrial ecosystems including photosynthesis, plant growth and productivity. This study was conducted to investigate the effects of experimental warming on the growth of Quercus variabilis seedlings. One-year-old Q. variabilis seedlings were planted in control and warmed plots in April 2010. The air temperature of warmed plots was increased by $3^{\circ}C$ compared to control plots using the infrared lamp from November 2010. Shoot height and root collar diameter were measured in March 2011 and June 2012, respectively, and aboveground and belowground biomass were also measured in March 2011 and 2012, respectively. Shoot height and root collar diameter were significantly higher in warmed plots than in control plots, except for root collar diameter in March 2011. Increment (mm) of shoot height and root collar diameter were also higher in warmed plots ($529{\pm}30$, $5.6{\pm}0.5$) than in control plots ($464{\pm}28$, $4.5{\pm}0.4$). However, there were no significant differences between warmed and control plots except for root collar diameter. Increment (g/year) of total, aboveground and belowground biomass were higher in warmed plots ($36.88{\pm}6.52$, $11.91{\pm}3.44$, $24.97{\pm}3.73$) than in control plots ($30.59{\pm}5.51$, $8.73{\pm}1.66$, $21.86{\pm}3.88$), however, the differences were not statistically significant. Higher seedling growth and biomass of warmed plots might be related to the enhanced net photosynthetic rates in spring and the extended growing season.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.84-93
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• 2016

Plant factories with artificial lights require a large amount of electrical energy for lighting; therefore, enhancement of light use efficiency will decrease the cost of plant production. The objective of this study was to enhance the light use efficiency by using filters to diffuse the light from LED sources in plant factory conditions. The two treatments used diffuse glasses with haze factors of 40% and 80%, and a control without the filter. For each treatment, canopy light distribution was evaluated by a 3-D ray tracing method and canopy photosynthesis was measured with a sealed acrylic chamber. Sixteen lettuces for each treatment were cultivated hydroponically in a plant factory for 28 days after transplanting and their growth was compared. Simulation results showed that the light absorption was concentrated on the upper part of the lettuce canopy in treatments and control. The control showed particularly poor canopy light distribution with hotspots of light intensity; thus the light use efficiency decreased compared to the treatments. Total light absorption was the highest in the control; however, the amount of effective light absorption was higher in treatments than the control, and was highest in treatment using filters with a haze factor of 80%. Canopy photosynthesis and plant growth were significantly higher in all the treatments. In conclusion, application of the diffuse glass filters enhanced the canopy light distribution, photosynthesis, and growth of the plants under LED lighting, resulting in enhanced the light use efficiency in plant factory conditions.

• Korean Journal of Remote Sensing
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• v.40 no.3
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• pp.275-284
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• 2024

Monitoring crop growth changes and water content is crucial in the agricultural sector. This study utilized drones equipped with Short Wavelength Infrared (SWIR) sensors, sensitive to moisture changes, to observe soybeans' growth and water content variations. We confirmed that as soybeans grow more vigorously, their water content increases and differences in irrigation levels lead to decreases in vegetation and moisture indices. This suggests that waterlogging slows down soybean growth and reduces water content, highlighting the importance of detailed monitoring of vegetation and moisture indices at different growth stages to enhance crop productivity and minimize damage from waterlogging. Such monitoring could also preemptively detect and prevent the adverse effects of moisture changes, such as droughts, on crop growth. By demonstrating the potential for early diagnosis of moisture stress using drone-based SWIR sensors, this research suggests improvements in the efficiency of large-scale crop management and increases in yield, contributing to agricultural production.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.1
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• pp.44-54
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• 2001

This study was conducted to estimate microclimate of natural deciduous forest in national forest of Pyungchang, Kangwon province and to investigate the effects of the microclimatic conditions on the periodic annual increment of diameter by site types. In this study, site was first classified by nine types considering both elevation (higher than 1,000 m, 700∼1,000 m, and lower than 700 m) and topographical conditions (ridge, slope and valley). For each of site types, diameter growth was measured by using increment borer and periodic annual increment of diameter was then analyzed. A topoclimatological technique, for estimating microclimatic conditions, which make use of empirical relationships between the topographical factor and the climatic normals in the study area was applied to produce monthly mean, maximum and minimum temperatures, relative humidity, precipitation and hours of sunshine. From these monthly estimtes, 17 weather variables such as warmth index, coldness index, index of aridity etc. which affect the diameter growth were computed for each of site types. The periodic annual increment of diameter was then correlated with and regressed on the 17 weather variables to examine effects of microclimatic conditions on the diameter growth by site types. From the correlation analysis, it was found that the diameter growth by site types was positively correlated with all of 17 weather variables except the warmth index. Especially, the conditions such as high relative humidity and large amount of sunshine hours provide favorable environment for the growth of diameter. On the other hand, it was also found that diameter growth was negatively iufluenced by warmth index. According to the regression analysis, the periodic annual increment of diameter could be well predicted by index of aridity and mean relative humidity for the growing season.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.443-449
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• 1997

We examined the effect of pretreatments on seed germination, seedling growth, optimal seedling density of Phellodendron amurense. The seeds were carefully purified after collection in late Oct. from natural population at Mt. Chiri. For the evaluation of pretreatment effects, seeds were sowed in an experimental nursery after being stored in open ground($2{\sim}8^{\circ}C$) with soaking in 20% $H_2O_2$, 50-fold pon-pon solution, cold moist stratification in refrigerator($2{\sim}4^{\circ}C$) and dry storage in roam temperature($4{\sim}18^{\circ}C$), respectively, For the effect of growth density of seedlings, seedlings germinated in nursery were precisely controlled with 53, 104, 220, 380 seedlings per $m^2$. Among pretreatments for the promotion of germination rate, pon-pon treatment(68.8%) was highest, the others were higher than that in dry storage(2.3%), and these seed pretreatment methods were significantly different at 1% level. The height growth of seedlings showed the most vigor from Jun.12 to Jul. 8, and from Jul.20 to Aug. 2, and it reached to 72.8% of height growth. In case of 1-0 seedling, although seedling density per $m^2$ was increased, seedling growth was decreased. The optimal seedling density was 104 seedlings per $m^2$. The standard seedlings for plantation were above height 55cm, root collar diameter 8.1mm, and root length 21cm. These results demonstrated that seed of P. amurense requires stratification for the germination promotion.

• Korean Journal of Environment and Ecology
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• v.21 no.5
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• pp.449-455
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• 2007

To offer basic data for restoration technology development of the evergreen broad-leaved forest, this researcher did monitoring on the restoration project of the evergreen broad-leaved forest implemented in Dadohaesang(Marine) National Park for three years starting the year 2005, As a result of the monitoring job of tree height and survival rate of the evergreen broad-leaved forest on the 5 model afforestation-testing sites subsequent to the slanting surface, size of island, and whether the pastured livestock exist or not, it was found that the tree height & survival rate of the evergreen broad-leaved trees planted on the ridge parts of the southwest slanting surface were in better condition than those of the evergreen broad-leaved trees planted on the ridge parts of the northeast slanting surface. The survival rate of the evergreen broad-leaved tree planted on a big island was revealed to be higher than that of the evergreen broad-leaved tree planted on a small island. In addition, the survival rate of the evergreen broad-leaved tree planted in a place where livestock was pastured was revealed to be much lower than that of the evergreen broad-leaved tree planted in a place where there was no livestock. Conclusively, there showed a good tree hight and survival rate of the evergreen broad-leaved tree planted on the ridge parts of the southwest slanting surface, on a big island, and at the place where there was no pastured livestock.

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.1-5
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• 2016

BACKGROUND: Burcucumber(Sicyos angulatus L.) is an invasive plant species and disturbs ecosystems in Korea. The main method for prevention of burcucumber is cutting or pulling out. However, the studies accounting for the use of the by-product of burcucumber after cutting remain incomplete. Thus, the aim of this study was to investigate the applicability of burcucumber as a substitute for nitrogen fertilizer.METHODS AND RESULTS: Burcucmber plants only including stem, leaves, and petiole were collected from the Sky Park in Seoul and divided in to three categories based on the length of stem of burcucumber; 10-30 cm, 30-100 cm, and 100-200 cm. And they were input into soil with 20 kg-N/10 a. After 4 weeks aging, chemical properties of treated soils and the productivity of lettuce(Lactuca sativa L.) were examined. Both the inorganic nitrogen contents in soils and the growth of lettuce were increased with the decreases in length of burcucumber standing for young plant. And the inorganic nitrogen content and the productivity of lettuce were positively correlated(r= 0.9409).CONCLUSION: The C/N ratio of burcucumber was low, indicating fast decomposition and nitrogen supplying rate, resulting in the increase in lettuce growth. Burcucumber could be a good substitute for nitrogen organic fertilizer.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.04a
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• pp.62-66
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• 1999

야생화를 도시환경 조성에 이용하고저 대량 육묘기술 중 알맞는 관수방법과 양액을 구명하기 위하여 꽃향유를 공시하여 시험한 결과 다음과 같았다. 1 2개월 육묘시 저면 양액 담배수 관수 방법이 지상 관수에 비해 10배나 높은 생장량을 보였다(지상관수 자료는 Data에는 보이지 않음). 2. 뿌리발달로 보아 저면 양액 관수방법은 2개월 육묘로도 가능하였지만 지상 관수는 3개월 육묘해야 화단에 정식 할수 있을 것으로 보였다. 3. 2개월 육묘 저면 양액 관수시 양액농도는 1/2S의 Sonneveld 기준액이 가장 좋았고 N, K 는 약간 늘려주는 것이 좋았다. 4. 식물체내 무기물 성분은 저면 양액 관수가 높았고 생장량이 많았던 구가 비교적 높았다. 5. 화단에 정식시켜 개화기의 관상가치는 지상관수나 저면 양액 관수가 별 차이를 보이지 않아 흡비력이 높은 이 야생화는 육묘시는 다소 생장이 떨어져도 화단에서는 대체로 같아졌다. 6. 개화기의 초장도 3/2S와 Hyponex구에서 가장 컸으나 초장은 너무 커서 재배적으로 좀 줄여줘야 더 좋을 것으로 보여 S나 1/2S도 좋을 것으로 생각되었다.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.142-147
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• 2009

The effects of short-term waterlogging on physiological responses, fatty acid compositions and yield components of rapeseed at both the vegetative growth and the reproductive growth stages were assessed in this study. Waterlogged plants were treated for a period of 10 days at the vegetative growth stage and 4 days at the reproductive growth stage. The results show that photosynthesis and stomatal conductance at both the vegetative growth and the reproductive growth stage were significantly reduced during the waterlogging period and after the recovery period. When the plants were removed from water, photosynthesis and stomatal conductance progressively restored similar values to those of control plants within $2{\sim}3$ days. Fatty acid compositions were unaffected by waterlogging treatment. However, yield components (pod number and pod length) of the waterlogged treated plants at the reproductive growth stage were significantly reduced. These results suggest that short-term waterlogging may thus influence oilseed yield component.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.71-76
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• 1995

This study on Pinus desiflora in Kangwon Province has been performed for the purpose of classifying its growth area by geographical factors. To classify its growth area, the basic data which had were the measured values for annual ring width from cores were used. Individual variations in the measured values were removed through the standardization. Regional mean chronologies were estimated from the standardized values. The growth area was classified by the cluster analysis on the basis of the regional mean standardized indices. The results of this study shown that annual growth patterns to be clustered similar to geographical distribution in Kangwon Province. And the regional variations of annual growth patterns in the western part of Kangwon province were greater than those in the eastern part of Kangwon province.