• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.13-19
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• 1992

This study was conducted to determine the efficacy of using uniconazole,[(E)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazole-1-yl)-1-penten-3-ol)] as a phytoprotectant against $SO_2$ injury in snap been (Phaseolus vulgaris L. 'Strike'). Thirteen days prior to $SO_2$ fumigation, plants were given a 100 ml soil drench of uniconazole solution at concentrations of 0.02, 0.10, 0.25 and 0.50 mg/pot. All four uniconazole concentrations were significantly effective in providing protection against $SO_2$ exposure(3 h at 1.5 ppm), but uniconazole treatment above 0.02 mg/pot severely reduced stem elongation, leaf enlargement, flowering date and pod number and weight. Uniconazole treatment had little or no effect on stomatal conductance but reduced transpiration rate on a whole plant basis by nearly 40%. This may reflect an alteration in canopy structure by reducing stem elongation and leaf enlargement. Although uniconazole did not increase the activities of superoxide dismutase(SOD) and peroxidase(POD) in non-$SO_2$-fumigated plants, it significantly increased those enzyme activities in $SO_2$-fumigated plants. Chlorophyll concentration on the basis of unit area was increased 50-60% by uniconazole. However, the difference was not detected on the basis of dry weight. $SO_2$ increased variable chlorophyll fluorescence (Fv) 48% after 1.5 h of exposure in non-uniconazole treated plants but decreased Fv in the plants after 3 h of exposure. By appliing uniconazole, it was possible to maintain high Fv values in the latter group of plants. These results suggest that the phytoprotective effects of uniconazole are related to its growth-retarding properties as an anti-gibberellin as well as the increase of activites of free radical scavengers such as SOD and POD.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.15-27
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• 2005

The water and carbon cycles in terrestrial ecosystems are the essential database for better understanding of the causes and the current processes of climate change and for the prediction of its future change. CarboKorea and HydroKorea are dedicated research efforts to develop technologies to quantitatively interpret and forecast carbon/water cycles in typical landscapes of Korea. For this, stable isotope studies have been launched to genetically partition various components of carbon/water cycles in terrestrial ecosystems. From stable isotope studies, practical deliverables such as evaporation, transpiration and gross primary productivity (GPP) can be provided at scales from tower (footprint) to large watersheds. Such reliable field-based information will form an important database to be used for validation of the results from various eco-hydrological models and satellite image analysis which constitute main components of Carbo/HydroKorea project. Stable isotope studies, together with other relevant researches, will contribute to derive quantitative interpretation of carbon/water cycles in terrestrial ecosystems and support Carbo/HydroKorea to become a leading research infrastructure to answer pending scientific and socio-economic questions in relation to global changes.

• Journal of Ecology and Environment
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• v.39 no.1
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• pp.81-90
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• 2016

This study was to investigate the effect of salt stress on physiological characteristics such as plant growth, photosynthesis, solutes related to osmoregulation of Beta vulgaris. A significant increase of dry weight was observed in 50 mM and 100 mM NaCl. The contents of Chl a, b and carotenoid were lower in NaCl treatments than the control. On 14 day after NaCl treatment, photosynthetic rate (P_N), the transpiration rate (E) and stomatal conductance of CO₂ (g_s) were reduced by NaCl treatment. On 28 day after NaCl treatment, the significant reduction in g_s and E was shown in NaCl 200 mM. However, P_N and water use efficiency (WUE) in all NaCl treatments showed higher value than that of control. Total ion contents (TIC) and osmolality were higher than the control. On 14 day after treatment, the contents of proline (Pro) increased significantly in 200 mM and 300 mM NaCl concentration compared with control, whereas on 28 day in all treatments it was lower than that of the control. The contents of glycine betaine (GB) increased with the increase of NaCl concentration. The contents of Na⁺, Cl^-, GB, osmolality and TIC increased with the increase of NaCl concentrations. These results suggested that under severe NaCl stress conditions, NaCl treatment did not induce photochemical inhibition on fluorescence in the leaves of B. vulgaris, but the reduction of chlorophyll contents was related in a decrease in leaf production. Furthermore, increased GB as well as Na⁺ and Cl^- contents resulted in a increase of osmolality, which can help to overcome NaCl stress.

• Journal of Ecology and Environment
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• v.35 no.3
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• pp.203-212
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• 2012

The physiological effects of elevated $CO_2$ concentration and temperature were examined for Quercus gilva and Q. glauca grown under control (ambient $CO_2$ and temperature) and treatment (elevated $CO_2$ and temperature) conditions for 39 months. The objective of the study was to measure the long-term responses, in physiological parameters, of two oaks species exposed to elevated $CO_2$ and temperature. The photosynthetic rate of Q. gilva was found to be decreased, but that of Q. glauca was not significantly affected, after long-term exposure to elevated $CO_2$ and temperature. Stomatal conductance of Q. glauca was reduced by 21.7%, but that of Q. gilva was not significantly affected, by long-term exposure to $CO_2$ and temperature. However, the transpiration rate of the two oak species decreased. Water use efficiency of Q. gilva was not significantly affected by elevated $CO_2$ and temperature, while that of Q. glauca was increased by 56.6%. The leaves of Q. gilva grown under treatment conditions had an increased C:N ratio due to their reduced nitrogen content, while those of Q. glauca were not significantly affected by long-term exposure to elevated $CO_2$ and temperature. These results suggest that the long-term responses to elevated $CO_2$ and temperature between Q. gilva and Q. glauca are different, and that Q. gilva, the endangered species, is more sensitive to elevated $CO_2$ and temperature than Q. glauca.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.43-49
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• 1995

The main purpose of these studies were to clarify differences in Cheju - scoria and other solid media on quantity and quality of cherry tomatoes and on shift of component of the nutrient solution, and to use Practically Cheju-scoria as an excellent solid culture medium. The results obtained were summarized as follows ; 1. Among scoria plots, the rates of dry weights, fruits and their sugar-acid ratio were higher in the plot that was drained well with deep flow for one hour once a day. 2. Fresh fruit weights were lighter in rockwool and deep flow technique, but larger in scoria, Hyugashi (artificial gravel, $\Phi$10-12mm) and perlite in moving to higher flower cluster. 3. The results of analysis on microelement among solution components showed decrease of concentrations of P and K in the period of growth and development. 4. Yields and brix of cherry tomato showed a tendency to increase in rockwool and Hyugashi than anothers. 5. The concentration of fertilizer base was increased in general solution culture. Transpiration and absorption were similar in scoria plot and other media. 6. More studies of the Cheju-scoria development is required in order to use it as a solid medium for solution culture.

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.245-251
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• 2003

This study was cnducted ton investigate the effect of soil conditioner such as dolomite, slkudge and organic manure on changes of soil chemical properties of abandoned zinc mine area. Growth responses of Chrysanthemum azwadskii and Caryopteris incana (Tunb) Miq affected by the appication were also determined. In thejsoil of abandoned zinz mine area, total heavy metal contents espectially Cd, Cu, Pb and Zn were high and organic matter contents was low. Application of sludge for phytoremediation resulted in higher soil organic content that other treatments tested. Heavy metal concentrations after application of soil conditioners were not different among treatments. The growth of C. zawadskii and C. incana (Tunb) Miq were significantly higher in sludge treatment than those in other treatments The cholrophyll content, chlorophyll flouorescence, protein content, photosynthetic rate and transpiration were high in sludge treatment. The heavy metal contents of C. zawadskii were the lowest in sludge treatment while those of C. incana (Tunb) Miq was the highest in sludge treatment.

• Journal of Bio-Environment Control
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• v.16 no.1
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• pp.1-6
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• 2007

This experiment was conducted to possibility for leaf production of wasabi using hydroponics system. When they were grown in aeroponics and soiless culture such as saprolite and Coir, photosynthesis and transpiration rate were high and marketable yield $(leaf\;width\;11{\sim}13cm)$ showed $11.2{\sim}11.7$ of leaf number per plant and $52{\sim}53.8g$ fresh weight. In spring periods, the highest yield was 25.7 of leaf number per plant in nutrient solution of Yamasaki's solution developed in Japan in deep culture during 130 days. It showed be possibility that marketable leaves harvested one leaf every $2{\sim}4$ days though spring and fall culture periods using hydroponics controlled in environmental culture.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.297-301
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• 2009

Hydrogen peroxide, which is used in various crops as an oxidizer to improve high temperature adaptation, was evaluated on the effects on productivity and disease incidence in paprika (Capsicum annuum L.) by periodic leaf spray at summer. Hydrogen peroxide treatment not only increased the leaf thickness and SPAD (chlorophyll content) but also the fruit set numbers per plant by 2. Hydrogen peroxide content increase in leaf resulted in increase of catalase and peroxidase activities, and the powdery mildew disease (Leveillula taurica) was also suppressed by the treatment. Transpiration was improved by the reduced leaf stomata resistance in the hydrogen peroxide treatment. Therefore, hydrogen peroxide leaf spray is recommended for improvement of summer productivity in paprika.

• Journal of Korean Society of Forest Science
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• v.94 no.4 s.161
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• pp.281-286
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• 2005

Trees enhance slope stability against down slope mass movement through the removal of soil water by transpiration and by the mechanical reinforcement of their roots. To assess the magnitude of this reinforcement on natural slope stability, direct shear tests were made on dry sand reinforced with different array types of roots. Pinus koraiensis was used as root specimens. The peak shear resistance at each normal stress level was measured on the rooted and unrooted soil specimens. Increased soil resistance(${\Delta}S$) by roots was calculated using parameters like internal friction angle and cohesion of tested soil and also evaluated the effects of root array in tested soil. As results, we find that shear resistance increased in tested soil shear box as diameters and arrayed numbers of root specimen increased and cross root array in tested soil had a much greater reinforcing effect than other root arrays. Comparison of traditional root-soil model with experiments showed that simulated reinforce strength by the model was different with those obtained by the experiment due to its linearity.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.221-228
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• 1999

This study measured the seasonal changes in physiological characteristics and antioxidants of Alnus firma to compare several enzyme activities(Rubisco, Superoxide dismutase(SOD) and Glutathione Reductase(GR)) between resistant and sensitive Alnus firma trees. Resistant and sensitive Alnus firma individuals near Yochon industrial complex were selected to conduct this study in 1997. Photosynthetic capacity, stomatal conductance, transpiration, Rubisco, SOD and GR activities of resistant trees which had no visible damages to air pollution were higher than those of sensitive trees in same area. All physiological results supported that biochemical process to be one of the important key features to understand resistance to air pollution. Increases of photosynthetic capacity and antioxidant enzyme activity in resistant trees in response to air pollution were the results of biological compensation to stress.