• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.186-195
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• 2017

This research aims to study the physiological characteristics of poplar clones in Saemanguem reclaimed land where has lower minerals and bad drainage than those in paddy field. In July and August, different poplar clones including Populus euramericana clone (Venziano and L.Avanzo) and deltoides hybrid clone (97-18 and 97-19) showed different physiological characteristics. Physiological characteristics of P. euramericana clones were better than those of P. deltoides hybrid clones. Especially, the average net photosynthetic rate ($A_{net}$) of clone Venziano were $18.62{\mu}mol\;CO_2\;m^{-2}{\cdot}s^{-1}$ and $17.11{\mu}mol\;CO_2\;m^{-2}{\cdot}s^{-1}$, respectively. Those were the highest numerical values among other poplar clones. On the other, the total chlorophyll and carotenoid contents of P. deltoides hybrid clones were higher than those of P. euramericana clones in July. Particularly, the total chlorophyll content of clone 97-18 was $2.37mg{\cdot}g^{-1}FW$. In August, those of P. deltoides hybrid clones decreased than in July. In term of the physiological activity such as net photosynthetic rate and stomatal conductance of P. deltoides hybrid clones were much lower in August than in July. As a result, physiological characteristics of P. euramericana Venziano clone was superior than the other clones in Short rotation coppice (SRC) in Saemanguem area.

• Journal of Forest and Environmental Science
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• v.19 no.1
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• pp.18-24
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• 2003

This study was made on the physiological reactions of photosynthesis. stomatal transpiration. stomatal conductance of Acanthopanax senticosus of leaves. The results obtained are as follows 1. The light compensation points were approximately $30{\mu}molm^{-2}S^{-1}$ in sun leaves and $15{\mu}molm^{-2}S^{-1}$ in shade leaves. 2. The light saturation points were approximately $1,000{\mu}molm^{-2}S^{-1}$ in sun leaves and $300{\mu}molm^{-2}S^{-1}$ in shade lea ves. 3. There was no significant between various mountains distributed. net photosynthetic rates were approximately 8.0 to $8.8{\mu}molm^{-2}S^{-1}$ in upper leaves. However. net photosynthetic rate in upper leaves of Acanthopanax koreanum in Jeju island was slightly low about $6.9{\mu}molm^{-2}S^{-1}$. 4. Net photosynthetic rate in middle leaves of all mountains was ranged from 40% to 65% of upper leaves. and that in lower leaves was approximately 30% of upper leaves. But the net photosynthesis in lower leaves of Acanthopanax koreanum in Jeju island was slightly high about 71 % of upper leaves. 5. There was no significant between various mountains distributed, stomatal transpirations were ranged from 1.1 to $1.4mmolH_2Om^{-2}S^{-1}$ in upper leaves, 0.7 to $1.0mmolH_2Om^{-2}S^{-1}$ in middle leaves, and 0.5 to $0.6mmolH_2Om^{-2}S^{-1}$ in lower leaves. respectively. 6. There was no significant between various mountains distributed. the stomatal conductance in upper 1eaves was ranged from 70 to $90mmolH_2Om^{-2}S^{-1}$. However, stomatal conductance in upper leaves of Acanthopanax koreanum in Jeju island was approximately $380mmolH_2Om^{-2}S^{-1}$, its remarkedly higher than any other mountain.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.147-152
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• 2012

This study was conducted to investigate the photosynthetic R. micranthum by natural habitats. In the results, natural habitats didn't affect values of light saturated point, light compensation point and photosynthetic capacity of R. micranthum. We investigated light response curve and chlorophyll content at each habitat. Light compensation points were 11.8 ${\mu}mol\;m^{-2}\;s^{-1}$, 11.5 ${\mu}mol\;m^{-2}\;s^{-1}$ and 10.4 ${\mu}mol\;m^{-2}\;s^{-1}$ in Seokpo-ri, Yeonha-ri, and Mt. Worak. Light saturation points showed that R. micranthum is shade tolerant specie which has the light saturation point approximately 500~600 ${\mu}mol\;m^{-2}\;s^{-1}$. Photosynthetic rates of R. micranthum leaves were 5.5 ${\mu}mol\;m^{-2}\;s^{-1}$, 5.4 ${\mu}mol\;m^{-2}\;s^{-1}$ and 5.6 ${\mu}mol\;m^{-2}\;s^{-1}$ in Seokpo-ri, Yeonha-ri and Mt. Worak. On the other hand, since between $20^{\circ}C$ and $30^{\circ}C$, it appeared that the values of net photosynthetic rates of R. micranthum leaves in all sites were high. Especially, the rates were highest at $25^{\circ}C$. Because of low stomatal transpiration rate in saturation radiance, the moisture utilization efficiency in Yeonha-ri was lower than other habitats. Rates of chlorophyll a, chlorophyll b, and total chlorophyll content in Mt. Worak were no significant difference. Therefore R. micranthum has characteristic of shade tolerant species. The moderate temperature for R. micranthum is between $20^{\circ}C$ and $30^{\circ}C$.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.158-162
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• 2012

The acclimatization of in vitro propagated plants is an important step to produce vigorous plants for clonal forestry and in vitro micro-environment may affect the growth in ex vitro condition. To monitor in vitro environmental effects on the growth in ex vitro condition, several culture systems such semi-solid medium(SS), temporary immersion bioreactor(TIB) and continuous immersion bioreactor(CIB) culture types were tested to compare for the growth of acclimated plants of Liriodendron tulipifera. Results suggested that morphological characters, stomatal conductance, evapotranspiration and chlorophyll contents of acclimated plants were affected by the different of in vitro culture conditions. CIB type of culture was resulted to the lowest value in the biomass of acclimated plants. Net photosynthsis rate of CIB was the same level as those of SS and TIB. However, stomatal conductance, evapotranspiration and $CO_2$ partial pressure in the intercellular air space were lower than those of SS and TIB. The amounts of chlorophyll a, b and carotenoids were also lower than those of the other two culture systems. TIB, showing a little lower or higher value than SS in many growth character, is recommended rather than CIB to produce healthy yellow poplar plants in ex situ condition.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.31-37
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• 2005

To find out temporal variations of net photosynthetic rate (NPR) of intertidal flats, we measured oxygen microprofiles in sediments with oxygen microsensors 4 times from December 2003 to June 2004. The study areas were the intertidial flats in Janghwa-ri and Dongmak-ri, located on the southwestern and the southern parts of Ganghwa-gun, respectively, and in Incheon North Harbor where the content of organic matter was relatively high. During the investigation, oxygen penetration depths in the tidal flats of Janghwa-ri and Dongmak-ri were high in December (mean values of 4.0-4.1 mm). Thereafter, the oxygen penetration depths declined to mean values of 2.2-2.8 mm and 1.6-1.8 mm in the two tidal flats. Interestingly, the oxygen penetration depths in the Incheon North Harbor tidal flat showed a lower range $(0.8{\pm}0.3\;mm;\;mean{\pm}1SD)$ over the period. The maximum NPR in the Dongmak-ri tidal flat was found in March $(11.1{\pm}2.8\;mmol\;O_2\;m^{-2}\;h^{-1})$, and those In Janghwa-ri $(6.1{\pm}4.1\;mmol\;O_2\;m^{-2}\;h^{-1})$ and Incheon North Harbor $(6.4{\pm}1.4\;mmol\;O_2\;m^{-2}\;h^{-1})$ were observed in May. During the period when NPR was most active, the highest oxygen concentration was found at 0.1-0.5 mm depth below the surface sediment, and was on average 1.8-3.2 times higher than the air-saturated oxygen concentration in the overlying seawater. Although we took into account of low in situ light intensity $(400{\mu}Einst\;m^{-2}\;s^{-1})$ during the investigation in June, NPR in the 3 study areas decreased significantly to less than $0.2\;mmol\;O_2\;m^{-2}\;h^{-1})$. Thus, temporal variations of NPR were somewhat different among the tidal flats. Generally, benthic primary producers inhabiting in the uppermost 0.5 mm of the sediment showed a peak photosynthetic activity in the study areas in spring. This is the first domestic report on photosynthetic rates of benthic microflora in the tidal flats with oxygen microsensors, and the use of the microsensor can be widely applied to measurements of benthic primary production of a tidal flat and the oxygen consumption rate of surficial sediments.

• 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.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.171-180
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• 2020

The effect of three different light qualities on growth, photosynthesis, quality and safe parameters of hydroponic cultivated spinach (Spinacia oleracea L.) were investigated indoor. Three different light qualities were created of red (660 nm), blue (450 nm) and green (550 nm) LEDs corresponding at ratio R660/B450 = 4/1 (RBL); R660/B450/G550= 5/2/3 (WWL); R660/B450/G550 = 1/1/1 (WL), which were tested at the same intensity (PPFD =190 μmol m^-2 s^-1). The results showed that the plant height and leaf number were the lowest in WL treatment. The SPAD, Net photosynthesis rate Pn, Fv/Fm, Leaf area index LAI values and all parameters of root characteristics were the highest in RBL treatment and were significantly different from two others. Fresh weight of stem, leaf and root, dry weight of root in the three light qualities were significantly different. In contrast, the highest K⁺ content in WL was different from WWL and RBL treatments, while Ca²⁺ and Fe²⁺ content were the highest in the RBL treatment. Vitamin C content was significantly different between the three treatments. nitrate and oxalic acid contents were the highest in WL treatment, whereas soluble-solids contents and vitamin C contents were the highest in RBL treatment. Oxalic acid, nitrate contents were observed tending reduced under WWL although oxalic acid content in RBL treatment was not different from WL and WWL treatments. In all three different light treatments were not detected Salmonella, E.coli. Our results suggest that RBL may be appropriate light for growth of spinach, but supplementary green light to a combination of red and blue LEDs at the reasonable rate can change the quality of spinach in a positive direction. Hydroponic cultivated spinach was safe for users.