• Journal of Environmental Science International
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• v.22 no.10
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• pp.1345-1351
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• 2013

Leaf characteristics of two representative deciduous-tree species in Korean peninsula were compared to assess directional ridge effect on leaf traits of both species. Leaf mass per unit area (LMA) of Rhododendron schilippenbachii in south-facing ridge slope was significantly higher than that in north-facing ridge slope, while Quercus mongolica did not change LMA. Leaf mass of Q. mongolica was increased depending on leaf size irrespective of slope. However, leaf mass of R. schilippenbachii changed differently in responding to expansion of leaf area between both slopes resulting from retardation of leaf expansion in south-facing slope. R. schilippenbachii showed higher leaf nitrogen concentration per unit area (LNCA) in south-facing slope than that in north-facing slope, while Q. mongolica indicated no difference in LNCA between southand north-facing slopes. However, both species revealed no significant difference in leaf nitrogen concentration per unit mass (LNCM) between south- and north-facing slopes. LNCA of Q. mongolica was about two times higher than that of R. schilippenbachii. These results indicate that there is a difference in leaf characteristics including leaf thickness and nitrogen allocation between Q. mongolica and R. schilippenbachii, suggesting the difference of plasticity.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.69-73
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• 2003

Specific leaf weight (SLW), defined as the mass of tissue per unit leaf area has been found to be an important physiological parameter as it indicates the relative thickness of leaves. Greater SLW provides more photosynthetic potential per unit area of leaf and hence it is frequently been considered as correlated with photosynthesis in several plant species. Collections of 165 mulberry (Morus sp.) germplasm accessions, both Indian and exotic in origin were evaluated for their variability with respect to SLW. The mean specific leaf weight ranged from 35.3 to $72.3 g/m^{-2}$. The distribution of SLW was found to be normal. High heritability (97.08%) and a small difference between genotypic and phenotypic variance demonstrates the genetic control over SLW. Significant heterotic effect with respect to SLW was observed in crosses when parents with high and low SLW were chosen.

• Journal of Environmental Science International
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• v.22 no.2
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• pp.187-193
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• 2013

Dry matter allocation characteristics of Calystegia soldanella, grown in pots, was analysed to assess its plasticity in response to water-stressed conditions. As water was withheld leaf water potential between the two watering treatments was similar during the first 6 days, followed by a rapid decrease in water-stressed plants. The minimum leaf water potential was -1.50 MPa on day 15 and the maximum leaf water potential was about -0.5 MPa on day 0 in water-stressed plants. In well-watered plants leaf water potential was maintained almost consistently throughout the experiment. There was no significant difference in plant dry weight between the two watering treatments for 9 days after the start of experiment and that was remarkably increased thereafter, compared with that remained without any increase in water-stressed plants. In dry mass partitioning, however, the water-stressed plants showed a great plasticity, showing that there were 1.81, 1.35 and 0.81 times increase in root, stem and leaf, respectively. Dry mass partitioning in well-watered plants varied from 2% to 5%. The difference of dry mass partitioning between the two watering treatments was reflected in leaf mass per unit area (LMA) and root/shoot (R/S) ratio. LMA in water-stressed plants was lower than that in well-watered plants, while R/S ratio in water-stressed plants was higher in well-watered plants. This means that the water-stressed plants reduced its leaf area and increased dry mass partitioning into root and stem during the progress of soil drying. These results indicate that Calystegia soldanella inhabiting in sand dune cope with water stress with high plasticity which can adjust its dry mass partitioning according to soil water conditions.

• Journal of Forest and Environmental Science
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• v.29 no.1
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• pp.38-48
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• 2013

Decomposition of plant material is an important component in the study of forest ecosystem because of its critical role in nutrient cycling. Different tree species has different nutrient release patterns, which are related to leaf litter quantitative traits and seasonal environmental factors. The quantitative traits of leaf litter are important predictors of decomposition and decomposition rates increase with greater nutrient availability in the forest ecosystems. At the ecosystem level, litter quantitative traits are most often related to the physical and chemical characteristics of the litter, for example, leaf toughness and leaf mass per unit area, and lignin content tannin and total phenolics. Thus, the analysis of litter quantitative traits and decomposition are highly important for the understanding of nutrient cycling in forest ecosystems. By studying the role of litter quantitative traits on decomposition and nutrient cycling in forest ecosystems will provide a valuable insight to how quantitative traits influence ecosystem nutrient dynamics. Such knowledge will contribute to future forest management and conservation practices.

• Journal of Environmental Science International
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• v.23 no.6
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• pp.1075-1083
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• 2014

The objective of this study was to evaluate the effect of cutting types on microclimate and growth characteristics of afforested tree in Quercus acutissima stand after different types of cutting. The difference in temperature reaching $5.2^{\circ}C$ was shown in between clear cutting and selective cutting treatments. On July and August days with temperatures more than $35^{\circ}C$ often appeared in clear cutting stand. The values of VPD in July and August were higher than those in other months. Maximum VPD of 3.99 kPa was shown in clear cutting stand on May 23 as a prolonged rainless days appeared. However, VPD in selective cutting stand always stayed under 3.0 kPa throughout growing season. A higher intensity was shown in clear cutting and strip clear cutting stands, reaching to more than $1,600{\mu}mol\;m^{-2}s^{-1}$ at midday on early August, while that in selective cutting stand stayed about 1,500. In relative growth rate selective cutting stand showed a significantly higher relative growth rate in plant height than those in other cutting stands (p<0.05). The number of leaf in current-year branches significantly increased in selective cutting stand, whereas no increase was shown in clear cutting and strip clear cutting stands (p<0.05). In addition, relative elongation rate of current year branch also showed higher values in selective cutting stand compared with that in strip clear cutting stand (p<0.05). However, leaf mass per unit area (LMA) was higher in order of strip clear cutting, clear cutting, and selective cutting stands. From these results it is concluded that environmental conditions in clear cutting and strip clear cutting stands during growing season are more stressful to afforested tree species, resulting in lower relative growth in plant height, elongation of current-year branches, and leaf number per branch compared with those in selective cutting stand. Consequently, more data must be accumulated in the field to find out best cutting type in plantation considering the adaptational characteristic of each tree species varies with species and life span of tree is long.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.3
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• pp.56-63
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• 2004

This study was carried out to find out the effect of by-product gypsum(phosphogypsum, PG) application on enhancement of turf quality. For the first experiment, 10 ton $ha^{-1}$ PG was applied to 1m${\times}$10m (width${\times}$length) Plots with 4 replicates on a sloping area of fairway where turf(Zoysia japonica L.) was grown. Both top- and sub-soil samples were collected before and after treatment and were analyzed for pH, EC(e1ectrica1 conductivity), Ca and Mg contents. At the same time when soil samples were collected, specific color difference sensor value(SCDSV) that represented chlorophyll contents, fresh and dry weight of the turf were determined to find out the effect of PG treatment on turf growth. SCDSV of turf from PG treated plots measured at 98 and 147 days after treatment were significantly higher than those from control. Considering higher fresh and dry weight of leaf per unit area from PG treated plots than that from control, it was concluded that the elevated Ca and S level of the PG treated plots resulted in vigorous leaf growth of turf. For the second experiment 2, 5 and 10 ton $ha^{-1}$ PG were applied to 1m${\times}$10m(width${\times}$length) Plots with 3 replicates at a closer location as was used for the first experiment to find out the appropriate PG application rate. Before and after treatment soil and plant samples were collected and were analyzed by the same way as the first experiment. The pH of all the soil samples collected from PG treated plots at 38 days after treatment was lower than that from control. This trend changed as time passed. However, the pH of the soil from 10 ton $ha^{-1}$ PG treated plot was lower than that from control during the whole period of the second experiment. SCDSV, fresh and dry weight of leaf from PG treated plots at all 3 rates were higher than those from control for the second experiment. PG application to turf will be beneficial for both mass consumption of by-product gypsum and enhancement of turf quality.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.3
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• pp.186-194
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• 1994

Lack of seedling vigor is considered a serious deterrent to use of broadleafed birdsfoot trefoil (Lorus comicul~rus L.). Our objectives were to compare early seedling growth of broadleafed birdsfoot trefoil cultivar "MO-20" and the large-seeded accession 302921 at $15^{\circ}C$ and $25^{\circ}C$. in controlled-environment chambers. Cabon dioxide exchange rate (CER) was measured in a closed or open system using infrared gas analysis. Dark respiration rate was measured manometrically. Net carbon accumulated per day and growth analysis of the seedlings were calculated. Initial seed mass of 302921 was 3.5 times larger and final cotyledon area was 2 times larger than those of MO-20, and early seedling growth was better. But, from 3 weeks after emergence until the end of the test period at $25^{\circ}C$, MO-20 showed higher CER per unit leaf area and faster dry weight accumulation than did 302921. Compared with $25^{\circ}C$, growth of MO-20 at $15^{\circ}C$ was suppressed more than that of 302921. Dark respiration rate of MO-20 was slightly higher than that for 302921, but not COz uptake per day for MO-20 was highest at$25^{\circ}C$ and lowest at $25^{\circ}C$. The relative growth rate (RGR) of MO-20 was higher than 302921 at $25^{\circ}C$ due to high net assimilation rate, but there was little difference in RGR between entries at $15^{\circ}C$.}C$.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.246-254
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• 2022

Domestic facility agriculture grows rapidly, such as modernization and large-scale. And the production scale increases significantly compared to the area, accounting for about 60% of the total agricultural production. Greenhouses require energy input to create an appropriate environment for stable mass production throughout the year, but the energy load per unit area is large because of low insulation properties. Through the rooftop greenhouse, one of the types of urban agriculture, energy that is not discarded or utilized in the building can be used in the rooftop greenhouse. And the cooling and heating load of the building can be reduced through optimal greenhouse operation. Dynamic energy analysis for various environmental conditions should be preceded for efficient operation of rooftop greenhouses, and about 40% of the solar energy introduced in the greenhouse is energy exchange for crops, so it should be considered essential. A major analysis is needed for each sensible heat and latent heat load by leaf surface temperature and evapotranspiration, dominant in energy flow. Therefore, an experiment was conducted in a rooftop greenhouse located at the Korea Institute of Machinery and Materials to analyze the energy exchange according to the growth stage of crops. A micro-meteorological and nutrient solution environment and growth survey were conducted around the crops. Finally, a regression model of leaf temperature and evapotranspiration according to the growth stage of leafy vegetables was developed, and using this, the dynamic energy model of the rooftop greenhouse considering heat transfer between crops and the surrounding air can be analyzed.