• FLOWER RESEARCH JOURNAL
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• v.17 no.2
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• pp.75-80
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• 2009

The objective of this research was to select the native shade tolerance plant which grows well from landscape objective of the urban. Seven species native ground cover plants were evaluated on the growth and chloropyll under 0, 40, 60, 90% shading treatments. Hosta longipes was showed the quite good growth from 60% level of natural light. The plant growth of Liriope platyphylla was good within $144.2{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ intensity which is 90% shade level of natural light. But, Dryiopteris crassirhizoma was judged with shade tolerance plant which grow quite well from shading condition level of 60% degree. Carex siderosticea was showed the highest plant length and plant width in 40% shading of natural light more than at conditon too much shading. Hosta longipes, Liriope platyphylla, Dryiopteris crassirhizoma, and Carex siderosticea were as shade tolerance plant with increases chlorophyll content well to overcome a light restrictive condition and is adapted to seem with the result.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.420-427
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• 1995

This study was carried out to investigate heterosis in photosynthetic characteristics and yield of F$_1$ hybrid rice using genetic cytoplasmic male sterile lines. Two F$_1$ hybrid rices, HR7028A/Yongmoonbyeo and IR54756A/Yongmoonbyeo, showed heterobeltiosis in dry weight and leaf area at the heading date and at the 20 day after heading. HR7028A/Yongmoonbyeo showed heterobeltiosis and IR54756A/Yongmoonbyeo showed heterosis in chlorophyll content and RuDPCase activity in flag leaf, T-sugar and starch content in stem, and $CO_2$ fixation at the 20 day after heading as well as at the heading date. HR7028A/Yongmoonbyeo showed heterobeltiosis in number of panicles and grains per panicle, and IR54756A/Yongmoonbyeo had heterobeltiosis in number of panicles per plant. As results, heterobeltiosis of HR7028A/Yongmoonbyeo in yield was 11% and that of IR54756A/Yongmoonbyeo was 4%.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.45-53
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• 2014

This study was conducted to evaluate the effect of developed composted liquid manure(DSCB), which was produced by adding N, P, and K to composted liquid manure(SCB), on the growth of zoysiagrass. Two different N sources used in DSCB were ammonium sulfate(DSCB-A) and urea(DSCB-U), respectively. Fertilizer treatments were designed as follows; non-fertilizer (NF), control (CF; chemical fertilizer), DSCB-Al($200mlm^{-2}$ DSCB-A), DSCB-A2($250mlm^{-2}$ DSCB-A), DSCB-U ($250mlm^{-2}$ DSCB-U) and CF+SCB(CF+$250mlm^{-2}$ SCB). In zoysiagrass, turf color index, chlorophyll index, dry weight and nutrient content were measured. Turf color index and chlorophyll index in DSCB and SCB treatment were increased by 1~3% and 14~28% than those of NF, respectively, and in DSCB-A1, DSCB-A2 and CF+SCB increased by 7~12% than those of CF. As applied with DSCB and SCB, the dry weight of DSCB-A1 and DSCB-A2 was increased by 25% and 19% in than CF, respectively and their nitrogen uptake by 19% and 6%. Evaluated with turf quality and growth, DSCB-A1 was the best and the most efficient in all treatments. These results indicated that application of DSCB-A1 promoted turf quality and growth of zoysiagrass by stimulating a nitrogen uptake, so that it was expected to replace to chemical fertilizers.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.164-174
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• 1994

Temporal changes in growth performances, chlorophyll contents, and tissue water relations for determining their physiological responses of five economic tree species subjected to chronic water and nutrition stresses were investigated with containerized seedlings grown in different soil moisture regimes and nutrition levels. Seedlings of Quercus acutissima, Q. variabilis, Q. mongolica, Q. serrata, and Fraxinus rhynchophylla were propagated in plastic pots(I.D. $16cm{\times}Depth$ 16cm) for the experiments. The seedlings were subjected to two soil moisture regimes of dry and wet soils and two nutrition levels of fertilization with N+P+K and no fertilization through the growing season from May to September in a green house. For the purpose of analyzing their responses to the environmental stresses, seedling heights and root collar diameters, chlorophyll contents, and P-V curve parameters of the seedlings were measured in May, July, and September. The environmental stresses coming from moisture and nutrient deficits affected the growth performances of seedlings variously among species and among different growing periods, as well as between height and basal diameter growth of seedlings. The growth performances of Q. acutissima were influenced sensitively on the stresses, but those of Q. mongolica less influenced in comparison with other species. Chlorophyll contents were generally higher in Quercus spp. than F. rhynchophylla through the growing season. The chlorophyll contents changed by species and by treatment through the season within ranges of 0.14~1.96 mg/g dry wt. of chlorophyll a and within 0.16~1.79mg/g dry wt. of chlorophyll b, respectively. But the contents seemed to be decreased gradually through the chronic environmental stresses and leaf senescence. The osmotic potential at full turgor(${\Psi}{{\pi}o}$) and turgor loss point(${\Psi}{\pi}p$) had temporarily declined up to 3 to 5bars from -7.0~-12.4bars in May to -10.2~-17.5bars in September and up to 5 to 6bars from -7.6~-14.2bars in May to -12.9~-20.4bars in September, respectively, with some exceptions. The values of ${\Psi}{\pi}p$ were generally high in F. rhynchophylla in May and July, but high in Q. serrata in September. Relative water contents at turgor loss point(RWCp) were generally high in F. rhynchophylla, but the temporal changes of RWCp were quite and frequently different among species and among treatment.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.277-284
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• 2001

Since a substantial part of the total planktonic primary production is due to the activity of the picoplankton, seasonal change of chlorophyll a in the picoplankton, nanoplankton and microplankton was determined at four locations in Daechung Reservoir from September in 1998 to September in 1999. Chlorophyll a concentration (<$200\;{\mu}m$) was $0.7{\sim}36.9\;{\mu}g/l$ In TAE (Taejeon site), $0.5{\sim}23.5\;{\mu}g/l$ in MAN (Man site), $1.9{\sim}20.1\;{\mu}g/l$ in HOE (Hoenam site), and $0.5{\sim}17.4\;{\mu}g/l$ in DAM (Dam site). Generally it was observed the highest concentration of chlorophyll a was in September and the lowest in April to June. The relative contribution of chlorophyll a of each fraction was changed dramatically through the year. Relative contribution of chlorophyll a of microplankton was high from June to October, and low in March in all locations except HOE. However chlorophlyll a concentration of picoplankton fraction was $2.0{\sim}24.3%$ of total chlorophyll a (<$200\;{\mu}m$) through the year and did not show any dramatic changes at all locations.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.41-49
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• 2014

Four preparations of liquid turfgrass fertilizers were tested cool season turfgrasses during fall season. The preparations of PS-A, PS-B, PH-C and PH-D for commercial products were contained with essential nutrient elements, seaweed extract, amino acids, and humus substance. Growth and quality of creeping bentgrass (Agrostis palustris Huds cv. Penn-A1) and Kentucky bluegrass (Poa pratensis L.) mixture (Midnight 33%, Moonlight 33%, Prosperity 33%) were evaluated by normalized difference vegetation index (NDVI), root length and fresh weight, shoot density, turf color, and chlorophyll content. Three foliar sprays of 4 preparations with an interval of 7 days were made in the fall of 2013 in the sod production field at Hapchun, Korea. No significant difference among 3 preparations was found in NDVI of creeping bentgrass. However, PS-A was significantly increased NDVI of Kentucky bluegrass. Two to three applications of PS-A significantly increased chlorophyll content and turf color. Three foliar sprays of PS-A and PS-B were significantly increased the shoot density of Kentucky bluegrass on 20 days after final application. These results may indicate that the use of some preparation is beneficial in producing higher quality turfgrass sod with better color and chlorophyll content during fall season.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6388-6398
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• 2014

To understand size fractioned chlorophyll a and material cycle characteristics in Jeju marine ranching area (JMRA), 4 times of survey were conducted from April to November 2008. Picoplankton on the surface in JMRA was on average, $0.30{\mu}g/L$(annual mean(M):17.3%) in the $0.03{\sim}0.84{\mu}g/L$ range, accounting for 17.3%. Nannoplankton and picoplankton was on average, $1.35{\mu}g/L$(M:78.0%) in the $0.22{\sim}3.93{\mu}g/L$ range, and $1.73{\mu}g/L$(M:4.7%) in the nd ~ 0.24 range, respectively. The 10m layer was similar to the surface. The measured values changed according to the measurement times but the nanoplankton composition ratio was higher throughout the year. In addition, the size fractioned chlorophyll a distribution in JMRA was similar to that of tropical sea area affected by the Monsoon rather than South Korean offshore coast geographically adjacent to the East China Sea and Japan coastal waters affected by the Kuroshio/Tsushima warm currents. That is, the material cycle of JMRA consists of a microbial food web rather than traditional food chain at a lower trophic levels. Primary production is deemed to have a higher possibility of being adjusted by top-down dynamics, such as micro-zooplankton grazing pressure rather than nutrients supply.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1541-1555
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• 2022

Red tide has potential to harm marine ecology and aquaculture. Research on detecting red tide using various optical remote sensors has been conducted, but most of existing algorithms for detecting red tide has limitations, especially in shallow coastal waters with high levels of suspended sediment. For enhanced understanding of the optical behavior of red tide waters, analysis on remote sensing reflectance and water constituent is becoming increasingly important. This study analyzed the optical remote sensing data and water quality variables(Chl-a_(Spec), SPM, a_ph, a_d, Turbidity, Chl-a_(HPLC), Dominant species) of red tide waters. The data were collected from ship-based campaigns. In addition to the research on detecting red tide, the remote sensing reflectance and extinction coefficients for mesodinium and cochlodinium species were also analyzed. Through the analysis, it was possible to estimate the red tide chlorophyll concentration based on a specific wavelength of the remote sensing reflectance. The study found that chlorophyll concentration and phytoplankton absorption coefficient were highly correlated(R²=0.9), and that the RE_diff formula provided a more accurate estimate of red tide concentration than the B-G ratio.

• Journal of Korea Water Resources Association
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• v.56 no.3
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• pp.173-184
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• 2023

Due to climate change, algal blooms frequently occur not only in Korea but also around the world, and the risk of toxicity of harmful algae has recently been issued. It is known that the representative harmful algae, cyanobacteria, are caused by the intersection of three factors: water temperature, residence time, and nutrients. In this study, water quality simulation was carried out using EFDC, a three-dimensional numerical model, to analyze the variations in water quality due to the decrease of residence time according to the opening of Yeongju Dam in Naeseong-Cheon. In fact, the concentration of chlorophyll-a in Yeongju Dam in the summer of 2021 was significant, exceeding the 'algae warning' for a long time based on the previous algae warning system. On the other hand, as a result of performing the simulation under the condition that the dam gate was completely opened, the concentration of chlorophyll-a was mostly reduced below the 'algae warning' level during the simulation period. It was confirmed that reducing the residence time by restoring the flow of Naeseong-Cheon is a way to immediately reduce algae in Yeongju Dam.

• Journal of Korean Society of Forest Science
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• v.106 no.1
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• pp.33-39
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• 2017

This study was carried out in order to closely examine the growth and the physiological response by shading levels of a container seedling of Daphniphyllum macropodum which is known as the species of having shade tolerance in a warm temperature evergreen broad-leaved tree. The shading treatment was regulated with the shading level of full sunlight, and 35%, 55%, 75% of full sunlight. As a result of surveying the height and the root collar diameter growth by the shading level, the height was the highest with 13.2 cm under 35% of shading. The root collar diameter was the highest with 4.99 mm under full sunlight. The organ-based (leaves, shoot and root) dry mass production and the whole dry mass production were higher with 1.38 g, 0.47 g, 0.87 g, 2.72 g, respectively, in order of 35% shading. As for chlorophyll a, b, and the total chlorophyll content, the highest chlorophyll content was shown under 75% of shading with the relatively highest shading level. The ratio of chlorophyll a to chlorophyll b (a/b) was the highest under 35% of shading. The photosynthetic rate, stomatal conductance and water use efficiency were the highest with $12.3{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$, $0.27molH_2O{\cdot}m^{-2}{\cdot}s^{-1}$, $3.53{\mu}molCO_2{\cdot}mmol^{-1}H_2O$, respectively, under 35% of shading. As a result of surveying the whole experiment, D. macropodum grows nicely by maintaining 35% shading.