• Korean Journal of Agricultural Science
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• v.50 no.2
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• pp.181-192
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• 2023

Appropriate fertilization methods are required according to species to supply necessary nutrients to plants and prevent soil environmental contamination in nurseries. In this study, the effects of nitrogen and phosphorus fertilization on the growth of Liriodendron tulipifera and soil characteristics were investigated. After 16 fertilization treatments (4 levels of nitrogen × 4 levels of phosphorus) were applied to one-year-old L. tulipifera seedlings at the Yongmun Nursery Station of the Korea Forest Service, height, root collar diameter (RCD), biomass, leaf nutrients, and soil characteristics were investigated. The height increased as the amount of nitrogen and phosphorus fertilization increased, and the RCD was the highest in the ×2 treatment. Biomass growth was on average 40.0% higher for the treatment with high nitrogen fertilization compared to the low nitrogen treatment. The seedling quality index was the highest with nitrogen and phosphorus ×2 treatment. Leaf phosphorus and magnesium concentrations decreased when nitrogen fertilization was applied, and leaf potassium concentrations decreased as nitrogen fertilization increased. Soil pH and exchangeable potassium decreased as the amount of phosphorus application increased, and exchangeable magnesium decreased as the amount of nitrogen application increased and increased as the amount of phosphorus application increased. Considering the growth of L. tulipifera seedlings and changes in the soil characteristics at the nursery stage, twice the standard fertilization amount is the appropriate fertilization amount for nursery of the Yongmun Nursery Station. It is expected that this study will contribute to improving nursery soil fertilization management technology for healthy seedling production.

• Asian Journal of Turfgrass Science
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• v.9 no.1
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• pp.11-42
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• 1995

The investigation was made on the relationship among vegetation, net productivity, regrowth and soils of Moonheri-Wasoori, Soodowon-Sungilkyo and Mt. Kumhak grasslands in Chulwon area. The following conclusions have been made as the results of this study. The vascular flora of the grassland in Moonheri-Wasoori was composed of 102 species, the most of which were Medicago denticulata, Miscanthus sinensis, Arundinella hirta, Festuca ovina and Cassia nomame. The flora of Soodowon-Sungilkyn grassland was composed of 74 species, the most of which were Arundinella hirta, Miscanthus sinensis, Carex nanella, Festuca ovina and Cassia nomame. It of Mt. Kumfiak grassland was composed of 78 species, the most of which were Arundinella hirta, Carex nanella, Festuca ovina, Miscanthus sinensis and Aster scaber. These five species contributed greatly to the standing crop of live material which was in excess of 60% of it. The peak standing crop of each 413.7, 307.6 and $348.7g /m^2$ in Moonheri-Wasoori, Soo- dowon-Sungilkyn and Mt. Kuruhak grasslands wars reached in August under flooded conditions as a result of the growth of dominant species, Medicago denticulata and Arundinella hirta. The net prodution of organic matter was slight in some intervals but occurred throughout the growing season After cutting of grasses, the regrowth of new leaves mainly depended on growing stage and edaphic factors. Characteristics of the natural grassland soils, especially, concerning water, total nitrogen, avail-able phosphorus and exchangeable calcium were clarified and might be depend upon the quantity of plant production. Nitrogen, phosphorus and calcium concentration of leaves of Medicago denticulata, Arundinella hirta and Miscanthus sinensis were higher than of stems. Even if diem we diffurmem in the a-mb of nutrients among Medicago denticulata hirta and Miacanthus sinensis for single species and stands. they were covered by variations within species in the present survey. Key words: Competition, Production, Productivity, Regrowth, Soil Properties, Vascular Flora.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.422-428
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• 1999

The mineral status of native goats and forage species, namely; Cynodon plectostachyus, Pennisetum purpureum. Eleusine indica, Cynodon dactylon, Calopogonium muconoides, Centrosema pubescens, Leucaena leococephala, and Mimosa pudica in lahar affected areas of Concepcion, Tarlac, Philippines were determined. Forage and blood samples were collected six times in 1996-97, and analyzed for calcium, phosphorus, magnesium, sulfur, copper, iron, molybdenum, selenium, and zinc. Forage calcium and sulfur are non-limiting. Most species had low phosphorus, copper and selenium, while some had magnesium and zinc levels lower than the critical limit because of low mineral content and high percolation rate of lahar deposits. Iron and molybdenum were in excess. The effect of seasonal variation was observed only in copper, sulfur and iron. Average blood mineral concentration of the animals was above critical limit, but there were no significant differences between seasons. All the animals had plasma phosphorus and magnesium above critical level; but 20 % had low copper, zinc and selenium especially in dry season possibly due to insufficient amount of these elements and excessive molybdenum and iron in most forage. Conversely, calcium in forage was high; but 40 % of the animals had low plasma calcium concentration. Although no clinical signs of mineral deficiencies were observed, supplemental feeding would be important since the condition of the pasture in lahar-laden areas is not expected to improve in the next five years. Intensified use of L. leucocephala with better mineral profile would be ideal.

• The Korean Journal of Mycology
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• v.21 no.3
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• pp.235-245
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• 1993

The symbiotic properties of arbuscular mycorrhizal fungi(AMF) such as the absence and/or presence of symbiosis, spore density, and six factors of phycochemical properties of soil were investigated in the rhizosphere of seven sand dune plants and three control plants around Kum river. The infection of AMF was confirmed in all plants. Three genera, nine species of the AMF spores were identified in the sand dune; Ac. scrobiculata, G. aggregatum, G. convolutum, G. diaphanum, G. dimophicum, G. geosporum, G. vesiculiferum, G. tortuosum, S. pachycaulis. All of them were also found in the control, but S. pachycaulis were only separated in the sand dune. In the control, three genera, four species were identified; G. flavisporum, Gi. margarita, Sc. gregaria. Sc. persica. The species specificity was not found between the sand dune plant and AMF. However, the AMF was thought to be correlated with the soil factors. The spore density was stimulated with increase of the organic matter and the nitrogen content, but inhibited with the water content and the phosphorus content. In respect of the seasonal factor, the spore density was increased in the late growth period of plants.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.77-80
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• 2000

Various analytical methods such as electron microscopy, quinone analysis, and 16S rDNA sequencing studies were used to investigate the microbial communities and to identify the microorganisms responsible for enhanced biological phosphorus removal (EBPR) in an anaerobic/aerobic sequencing batch reactor (SBR) fed with acetate. Electron photomicrographs showed that oval-shaped microorganisms of about $0.7\;{\sim}\;1\;{\mu}m$ in diameter dominated the microbial sludge. These microorganisms contained polyphosphate granules and glycogen inclusions, which suggests that they are a kind of phosphorus accumulating organism. Quinone and 16S rRNA sequence analyses showed that the members of Proteobacteria beta subclass were the most abundant species, which were affiliated with the Rhodocyclus-likes group. Phylogenetic analysis revealed that the two dominating clones of the beta subclass were most distantly related to Propionivibrio dicarboxylicus DSM 5885 and Rhodocyclus tenuis DSM 109 with about 95% and 96% sequence similarity, respectively. Therefore, it was concluded that the oval-shaped organisms related to the Rhodocyclus-likes group are likely to be responsible for biological phosphorus removal in SBR operation supplied with acetate.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.163-167
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• 2000

To evaluate the water purification capacity of 4 emergent macrophytes in 4 tributaries of Mankyung River, nitrate reductase activity (NRA) and nutrient removal capacity were determined. Higher NRA occurred in emergent macrophytes such as Persicaria thunbergii and Oenanthe iavanica with 7.8 and 5.4 ${\mu}$moi NO$_2$ g$^{-1}$d.wt. h$^{-1}$. respectively. The nitrogen removal capacity of emergent macrophytes displaying higher NRA fell within the range of 0.85 to 1.95 mg g$^{-1}$d.wt. day$^{-1}$ and was higher in the order Phragmites communis > Persicaria thunbergii > Oenanthe iavanica > Zizania latifolia. The phosphorus removal capacity was within the range of 0.07 to 0.12 mg g$^{-1}$d.wt. day$^{-1}$ and was higher in the order Phragmites communis > Oenanthe iavanica > Persicaria thunbergii > Zizania latifolia. In all the domestic, industrial and agricultural wastewaters, Phragmites communis showed the highest nitrogen and phosphorus removal capacity; 1.36 and 0.0088 mg g$^{-1}$d.wt. day$^{-1}$ respectively. Among the 4 macrophytes. Phragmites communis was the most suitable species for water purification in 4 tributaries of Mankyung River.

• Ocean Science Journal
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• v.40 no.4
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• pp.183-190
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• 2005

We investigated the seasonal variability of tree alkaline phosphatase activity in seawater and alkaline phosphatase hydrolysable phosphorus (APHP) at 3 stations in Hiroshima Bay using alkaline phosphatase extracted from the dinoflagellates Alexandrium tamarense and Gymnodinium catenatum. The dissolved inorganic phosphorus (DIP) was lower than $1\;{\mu}M$ all samples; the lowest values were in May. The amount of APHP was high at the surface and bottom waters of all stations in May, showing DIP-depleted conditions. In August and November, the amount of APHP was much less than the amount of APHP in May, indicating that the availability of dissolved organic phosphorus (DOP) for these species was low and/or uptake during the dinoflagellate blooming might have occurred in the area. The results obtained from short-term variations of AP activity might suggest that the growth of dinoflagellates in this season may be partly supported by the AP produced by other diatoms.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1105-1115
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• 2018

The aim of this study was to collect crucial data for the improvement of water quality and ecosystem conservation by analyzing water samples, sediments, benthic macroinvertebrates, and fish in the Seosan reservoir. The average values of water quality parameters from 2001 to 2016 were a chemical oxygen demand of 10 mg/L, total nitrogen of 1.22 mg/L, and total phosphorus of 0.074 mg/L. Cadmium was detected in the range of 0.531-0.748 mg/kg in the reservoir sediment. Fish belonging to 6 families and 9 species were identified in the reservoir. The dominant species were Carassius auratus and Micropterus salmoides. Benthic macroinvertebrates belonging to 22 families and 28 species were identified. The ecological score of the benthic macroinvertebrate community was 15 inside the reservoir (St. 2). Micropterus salmoides, an invasive alien species, was determined to be the subdominant fish species based on the number of captures, and the presence of the invasive species, Sicyos angulatus L. and Paspalum distichum L. was confirmed among the land flora.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.505-515
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• 2015

The objectives of this study were to determine the effects of stream nutrient regime, N:P ratios and suspended solids on fish tolerance/trophic compositions and stream ecosystem health, based on multi-metric model, during 2008-2013. Also, stream ecosystem health was evaluated in relation to chlorophyll-a (CHL) as a measure of algal productivity or indicators of trophic state to water chemical parameters. Total number of sampled fish species were 50 and showed a decreasing trend from 2008 to 2013. The minnow of Zacco platypus, based on the catch per unit effort (CPUE), was the most dominant species (25.9%) among the all species. Spatial heterogeneity was evident in the fish tolerance guilds that showed the dominance of sensitive species (89%) in the headwaters (S1) and the dominance of tolerant species (57%) in the urban. These conditions were directly influenced by concentrations of nutrients and organic matter (COD). The N:P ratios, as a barometer of water pollution, had a negative linear function (R² = 0.40, P < 0.01) with CHL, and the ratios had an important role in changes of COD concentration (R² = 0.40, P < 0.01). Under the circumstances, the N:P ratio directly influenced the relative proportions of fish trophic/tolerance compositions. According to the regression analysis of omnivore (O_m) and insectivore sp. (I_n) on total nitrogen and total phosphorus, nitrogen had no significant influences (P > 0.05) to the two compositions, but phosphorus influenced directly the two guilds [slope (a) = -32.3, R² = 0.25, P < 0.01 in the I_n; a = 40.7, R² = 0.19, P < 0.01 in the O_m]. Such water chemistry and fish trophic guilds determined the stream ecosystem health, based on the multi-metric fish model.

• The Korean Journal of Ecology
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• v.19 no.6
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• pp.543-562
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• 1996

Zooplankton community structure and the factors correlated with community differences were examined in sandusky Bay (SB) and the open water of Lake Erie (LE, U.S.A.). SB zooplankton communities differed from those in LE by having a greater rotifer density and species richness. Keratella spp., Brachionus spp., and Pompholyx complanata dominated SB rotifers; Brachionus and Pompholyx were rarely seen in LE. Of 19 rotifer species observed, nine species were found only at SB sites. Ordination of zooplankton species abundance by detrended correspondence analysis (DCA) showed an overlap between SB and LE sites, but indicated a portion of the space that was occupied by only SB communities. The seasonal trajectories of zooplankton dynamics in the ordination space at SB sites differed from that of LE. The zooplankton most important in forcing site separation along a DCA Axis I at SB sites were Brachionus angularis, Pompholyx complanata, Keratella valga, Keratella quadrata, Filinia terminalis (rotifers), and Eubosmina coregoni and Daphnia (cladocerans). These species had axis scores which were significantly correlated (p<0.01) with bacterial density and bacterial phosphorus, total phosphorus, and algal density. Very high baterial density and very abundant bacterivorous rotifers in SB suggest that the transport of bacterial carbon through rotifers may be a relatively important link to higher trophic leaels. We believe that this "microbial carbon flow" from the base of the food web may be important in determining the suitability of SB as a spawning site and nursery for larval and juvenile fish.nile fish.