• Journal of Wetlands Research
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• v.14 no.2
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• pp.237-242
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• 2012

In order to determine the ecological characteristics of Quercus serrata and Q. aliena, which are potential natural vegetation of riverine in Korea, we cultivated the seedlings of two oak species under light, soil moisture and nutrient gradients from April to October in glasshouse. Then, we measured aboveground, belowground and total plant biomass and analyzed the differences in growth between two oak species. The two oak species showed decreasing growth with lower light intensity, but reduction in growth of Q. aliena was greater than that of Q. serrata. Q. serrata and Q. aliena had a constant growth state under soil moisture gradients, but Q. aliena grew well more than Q. serrata in lower soil moisture gradient. As soil nutrient availability decreased, the growth of Q. aliena was greater than Q. serrata. These results mean that the growth of two oak species is not affected by soil moisture, but the part of growth in Q. serrata may be positively affected in lower soil moisture condition. Also, Q. serrata has strong shade tolerance and the ability to adapt high nutrient condition relative to Q. aliena. Thus, Q. serrata and Q. aliena will be advantageous for the growth in stream ecosystem due to high light availability, but Q. serrata will be distributed near the lowlands by the water environment. Also, because the two oak species need high soil nutrient, it is important to preserve herbaceous vegetation to prevent nutrients that flowed in the streams.

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.656-666
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• 1996

Aspen demand has increased recently in the Great Lakes region in the United States. Since aspen has moved into the region in late 1800's, its growing stock has increased so as to change forestry industry of the Lake States. Intensive timber harvesting and biomass removal may cause nutrient depletion, especially on nutrient-poor sites. Forest nutrients and nutrient cycling were investigated in aspen stands of 7-10, 27-33, and 41-42 year-old growing on sandy soils in Minnesota. Nutrients added to the aspen stands by atmospheric deposition and soil weathering were efficiently absorbed and stored in the tree biomass. Aboveground biomass increased from $24.4t{\cdot}ha^{-1}$ at young stands to $139.2t{\cdot}ha^{-1}$ at mature stands. Nutrients accumulated in the tree biomass showed same magnitude of difference. Nutrients added to the site through atmospheric deposition were in the order of Ca, N, K, Mg, and P. Annual litterfall was greater in older stands. However, the amount of nutrients returned by litterfall was not significantly different among stand ages due to the greater nutrient contents in the litterfall of young stands. Litter decomposition and nutrient release rates were greater at young stands than at older stands. Likewise, nutrient availability was higher in young aspen stands and became lower as the stands grew older. Nutrient leaching loss was minimal at all stand ages. Soil N mineralization was greater at young stands than at older stands. Nutrient cycling process was facilitated in young aspen stands with an increased level of available nutrients, Based on the estimations of nutrient balance and nutrient removal by harvesting, Ca was the most critical element which was likely to be depleted if aspen stands are intensively harvested with short rotations.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.357-364
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• 2011

Proper light intensity, potting media, fertilization level, and shade tolerance were investigated to develop Orostachys (Korean name, Nungyu bawisol) as a potted ornamental plant. The best plant growth was shown at 52% shading. Although plant growth decreased at 82% shading, ornamental value maintained at that shading rate, which indicate that O. 'Nungyu bawisol' has high shading tolerance. At over 90% shading, some of the plants died and showed decolorization and standing erect in leaves, resulting in a big decrease in ornamental value. Potting medium of decomposed granite (DG) : fertilizer-amended media (FAM) : river sand (RS) (6 : 2 : 2, v/v/v) showed the best growth in potted O. 'Nungyu bawisol'. Fresh weight of shoot part was 16 g in DG : FAM : RS (6 : 2 : 2, v/v/v), which was over 2 folds of those at the other medium. Drenching of Hyponex solution diluted by 1,000~2,000 folds 1 time per week brought the highest results in fresh weight, plant width, and runner number. Particularly, fresh weight of shoot part was 13 g higher than that of control (16 g). Leaf color tended to be darkened as concentration of Hyponex solution increased.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.557-563
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• 2017

Gastrodia elata (Orchidaceae) is a perennial parasitic plant that has a unique lifestyle of being in a symbiotic interaction with fungi. The underground root of Gastrodia is used for medicinal treatment to cure high blood pressure, stroke, leukemia, headaches, and especially neurasthenia. This study is intended to investigate the effect of the global warming on the ecological responses of Gastrodia. We cultivated the small tuber of Gastrodia with the oak wood lot and mulberry fungus under control (ambient $CO_2$ concentration + ambient temperature, ACAT), temperature treatment (ambient $CO_2$ concentration+elevated temperature, ACET), and $CO_2$+temperature treatment (elevated $CO_2$ concentration+elevated temperature, ECET). The elevated $CO_2$ concentration was about twice in the ambient air while the elevated temperature was about $2^{\circ}C$ higher than the control group. And then we observed the growth and production of reproductive organs and the underground root. The observation showed that the number of flower stalk was highest at ACET and lowest at ECET. The flower stalk was longest at ACET and shortest at ECET. The inflorescence was longest at ACAT and shortest at ECET. The seed capsule was heaviest at ACET and lightest at ECET. The aboveground biomass was highest at ACET and lowest at ECET. The number of rhizomes was highest at ACET and lowest at ECET. The total rhizome biomass was highest at ACET and lowest at ECET. The average rhizome biomass was highest at ACET and lowest at ECET. The results showed that the growth of Gastrodia increased because of more active growth of Gastrodia elata when only the temperature increased and decreased when both $CO_2$ concentration and temperature increased, indicating the poor growth of Gastrodia elata under the global warming condition. Therefore, the Gastrodia elata plantation should be maintained at the temperature of $20-25^{\circ}C$ and not be exposed to a high $CO_2$ concentration.

• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.231-237
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• 2008

Objective of this research was to investigate the effect of calcium concentrations in the fertilizer solution on growth and development of Ca deficiency in 'Maehyang' strawberry (Fragaria $\times$ ananassa Duch.). The margins of the youngest leaves were scorched and they developed a cupped shape as they were expanded in Ca deficient plants. The vein area of the youngest leaves became brown when the deficiency became severe. The quadratic responses were observed in dry weight production to elevated Ca concentrations in fertilizer solutions with the highest growth in 4.5 mM treatment. The regression equation was y=2.4026+1.0209x-$0.098x^2$ $(R^2=0.3546^{***})$. However, tissue Ca contents increased lineally as the Ca concentrations in fertilizer solutions were elevated (y=1.2108+0.1333x, $R^2=0.9189^{***}$). In changes of the fresh weight and Ca concentrations in petiole sap, fresh weight production showed quadratic responses to elevated Ca concentrations in fertilizer solution, but Ca concentration increased lineally. The equations in changes of fresh weight and Ca concentrations were y=9.273+4.882x-$0.4245x^2$ $(R^2=0.4935^{***})$ and y=52.311+3.2917x $(R^2=0.6918^{***})$, respectively. When the concentration of calcium at which plant growth was retarded by 10% is regarded as critical concentration level, the calcium contents based on dry weight of above ground plant tissue and in petiole sap should be in the range between 1.6 to 2.25% and 63 to $79mg{\cdot}kg^{-1}$, respectively.

• Journal of Bio-Environment Control
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• v.28 no.1
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• pp.46-54
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• 2019

Experiments of local cooling and heating on crown and root zone of forcing cultivation of strawberry 'Seolhyang' using heat pump and root pruning before planting were conducted. During the daytime, the crown surface temperature of the crown local cooling treatment was maintained at $18{\sim}22^{\circ}C$. This is suitable for flower differentiation, while those of control and root zone local cooling treatment were above $30^{\circ}C$. Budding rate of first flower clusters and initial yields were in the order of crown local cooling, root zone local cooling and control in root pruning plantlet and non pruning plantlet, except for purchase plantlet. Those of root pruning plantlet were higher than those of non pruning plantlet. These trends were evident in the yield of the first flower cluster until February 14, 2018, and the effect of local cooling and root pruning decreased from March 9, 2018. The budding rates of the second flower cluster according to the local cooling and root pruning treatments were not noticeable compared to first flower cluster but showed the same tendency as that of first flower cluster. In the heating experiment, root zone local heating(root zone $20^{\circ}C$+inside greenhouse $5^{\circ}C$) and crown local heating(crown $20^{\circ}C$+inside greenhouse $5^{\circ}C$) saved 59% and 65% of heating fuel, respectively, compared to control(inside greenhouse $9^{\circ}C$). Considering the electric power consumption according to the heat pump operation, the heating costs were reduced by 55% and 61%, respectively.

• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.238-245
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• 2008

This study was carried out to investigate the effect of magnesium (Mg) concentrations in nutrient solution on growth of and nutrient uptake by 'Maehyang' strawberry. Tissue analysis based on dry weight and petiole sap were also conducted to determine the threshold level in plants when Mg deficiency disorders developed in strawberry plants. In the Mg deficient plants, the spotted yellowing or yellowing area developed on the interveinal area of mature leaves. The dark brown color also developed on the interveinal area of mature leaves with marginal browning or marginal necrosis. The response in dry weight production of 'Maehyang' strawberry to elevated Mg concentrations in nutrient solution was quadratic and the equation is y=6.84+1.7533x-$0.9278x^2$ $(R^2=0.1081^{***})$. But the Mg contents in tissue increased lineally with the equation of y=0.1764+0.1275x $(R^2=0.8307^{***})$. The trends of fresh weight production and Mg concentrations in petiole sap were also quadratic (y=24.127+7.3565x-$1.125x^2$, $R^2=0.2314^{^***}$) and linear (11.954+5.793x, $R^2=0.6869^{***}$), respectively. To prevent growth suppression, the Mg concentrations based on dry weight of above ground tissue and in petiole sap should be in the range of 0.30 to 0.65% and 19 to $40mg{\cdot}kg^{-1}$, respectively, fer the commercial production of 'Maehyang' strawberry.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.961-967
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• 2012

There have been many studies about efficiency of amendments for heavy metal stabilization through chemical assessment. The objective of this study was to evaluate the efficiency of several soil amendments (lime, agric-lime, dolomite, steel slag, fly ash and acid mine drainage sludge) on heavy metals stabilization through not only chemical but also biological assessments (phytotoxicity test) in abandoned mining area soil. In order to achieve the goal, we conducted preliminary screening experiment targeting 12 types of crop plants such as radish, young radish, chinese cabbage, winter grown cabbage, cabbage, bok choy, chicory, crown daisy, carrot, chives, spinach, and spring onion. The results of inhibition rates of early plant growth in metal-contaminated soil against non-contaminated soil and the correlations between inhibitions items showed that the bok choy was appropriate specie with respect to confirm the effect of several amendments. Several amendment treatments on contaminated soil brought about the changes in the root and shoot elongation of bok choy after 1 week. Agric-lime, dolomite and steel slag treatments showed the great efficiency of reducing on mobility of heavy metals using chemical assessment. But in contrary, these treatments resulted in the reduction of root and shoot elongation and only AMD sludge increased that of elongation, significantly. When considering both chemical and biological assessments, AMD sludge could be recommended the compatible amendment for target contaminated soil. In conclusion, biological assessment was also important aspect of decision of successful soil remediation.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.247-251
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• 2008

During a 35-day growth cycle, N, P, and K uptake was determined by measuring changes in their contents in culture solutions. At harvest, plants were separated into the roots, base organs and shoot, and dried for tissue analysis for N, P, and K. The uptake rates of N, P, and K followed cyclical patterns that was related to shoot development and harvest, but were independent of the transpiration rate. Uptake of N declined from 5.6 mmol $plant^{-1}$ $day^{-1}$ just prior to the cycle initiation to 4.0 mmol $plant^{-1}$ $day^{-1}$ at day 15. Uptake rate steadily increased as flower stems reached maturity up to 10.3 mmol $plant^{-1}$ $day^{-1}$ day 35. Uptakes rates of P and K followed similar patterns of N uptake. Tissue concentrations of N and P steadily decreased since day 15. Content of K was the lowest at day 20 and steadily increased thereafter. In the root tissue, N and K contents were the lowest at day 15, increased to day 30, and then decreased at day 35. Tissue P content was just a reverse of those of N and K.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.363-370
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• 2014

Various ecosystem carry out fundamental function of material circulation and energy flow through interrelationship with many environmental factors. Therefore, it is crucial to scientifically understand the value of nature to deduce correlation between environmental factor and change of ecosystem function. In this study, we determined the accumulated ecosystem carbon and characteristics of soil respiration on grassland vegetation in Namahangang basin in Namhangang Basin. It was found that the rate of soil respiration was highly correlated with the soil temperature in all communities. The measured soil respiration rates were $1,539mgCO_2\;m^{-2}h^{-1}$, $1,200mgCO_2\;m^{-2}h^{-1}$, $1,215mgCO_2\;m^{-2}h^{-1}$ in Miscanthus sacchariflorus, Phragmites japonica, Salix koreensis communities, respectively. Also, carbon quantities accumulated in litter and soil layers were $40.6tCha^{-1}$ (1.9+38.7), $46.9tCha^{-1}$ (43.0+3.9), $31.2tCha^{-1}$ (28.9+2.3) in M. sacchariflorus, P. japonica, S. koreensis communities, respectively.