• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.2
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• pp.51-60
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• 2003

Rice, which occupies about 60% of the farmland in Korea, is a staple crop in Asia. It not only absorbs $CO_2$ from the atmosphere, but also emits carbon in a form of CH$_4$. It has a potential role in the global budget of greenhouse gases because of its relative contributions of carbon absorption and emission associated with changing hydrologic cycle. To better understand its current and future role, seasonal variations of energy and $CO_2$ exchange in this critical ecosystem need to be quantified. The purpose of this study was to measure, document and understand the exchange of energy and $CO_2$ in a typical rice paddy in Korea throughout the whole growing season. Since late April of 2002, we have conducted measurements of energy and $CO_2$ exchange in a rural rice paddy at Hari site, one of the Korea regional network of tower flux measurement (KoFlux). After the quality control and gap-filling, the observed fluxes were analyzed in the context of micrometeorology and biophysics. $CO_2$ and energy exchanges varied significantly with land cover changes (e.g., plant growth stages), in addition to changes in weather and climate conditions. This study, reporting first direct measurement of energy and $CO_2$ exchange over a rice paddy in Korea, would serve as a useful database as one of the reference sites in AsiaFlux and FLUXNET.

• Korean Journal of Environment and Ecology
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• v.34 no.2
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• pp.130-141
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• 2020

National parks in Korea are subject to a survey of natural resources every five years, according to the Natural Parks Act. This study analyzed the insect diversity in each of the 21 national parks conducted as part of the Third Nature Resource Survey of National Parks (2010~2018). It compared insect diversity in each national park national biodiversity with insect diversity in all national parks and analyzed the uncollected sub-taxonomic groups of each taxonomic group and the legally protected species. The Third Nature Resource Survey identified 5,584 species in 456 families in 21 orders in all national parks, and they accounted for 31.3% of 17,848 species in the national insect diversity. By taxonomic group, Lepidoptera was the most frequently found with 2,195 species, followed by beetles (1,495 species), fellings (712 species), and stink bugs (515 species). By national park, Odaesan national park showed the highest insect diversity with 1,963 species, followed by Sobeaksan national park (1,511), Hanryeohaesang national park (1,321), Gayasan national park (1,282), Juwangsan national park (1,265), Dadohaehaesang national park (1,264), Woraksan national park (1,251), and Jirisan national park (1,240). The legally protected species included 3 species of endangered species rank I, 11 species of endangered species rank II, 12 climate change indicator species, 139 endemic species, and 532 species requiring approval for cross-border transfer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.303-309
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• 1990

To provide essential information of the role of marine bacteria on the dinoflagellate blooms, distribution of marine bacterial flora and dinoflagellate species was investigated in Chinhae Bay located in southern part of Korea from August 1989 to April 1990. Two hundred and fifty one strains of marine bacteria were isolated from seawater samples collected from the study area. Among them, Flavobacterium spp. and Acinetobacter spp. were the most dominant in bacterial flora. Another 32 strains which comprised 13 percent of total strains were Erythrobacter spp.. Based on the physiological character, Erythrobacter spp. were identified as Erythrobacter longus, Erythrobacter sp.(J-2) and Erythrobacter sp. (J-8). From the phytoplanktonic community, fourteen genera and twenty nine taxa of dinoflagellate species were identified. Based on the spatio-temporal frequence and abundance Gymnodinium sanguneum, Prorocentrum micans and Prorocentrum minimum were the aestival dominent species. However, Heterocapsa triquetra was appeared as predominant species in April. Cell density of about 2,000 cells/ml was prevailed in the bloom of August, but it developed into more intensive bloom of above 500 cells/ml in September. The water quality showed eutrophic or hypereutrophic condition, which was proved by high concentration of dissolved inorganic nitrogen, ortho-phosphate and chemical oxygen demand. Oxygen deficient water mass was found in the bottom overlying waters in August and September. High relationship between abundant bacterial flora and persistent dinoflagellate blooms in eutrophic condition would be approvable.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.266-272
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• 2008

The aim of this study was to investigate the effect of supplemental lighting with different lighting intensity during growth on the sugar and pyruvic acid content of onion bulbs. As the result of comparison with growth, the content of pyruvic acid and sugar at harvest, supplemental lightening condition showed better growth, lower pyruvic acid content and higher sugar content than control. As to the growth at harvest according to lightening condition, 'Josaeng-ssundeobol' showed better growth as the lightening increased and 'Damrojunggab' had no difference above $12{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR. 'Josaeng-ssundeobol' contained much more content of pyruvic acid and sugar than 'Damrojunggab'. 'Josaeng-ssundeobol' had the lowest pyruvic acid content in $24{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR and 'Damrojunggab' had no difference above the $12{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR. The sugar content of 'Josaeng-ssundeobol' had no big difference above $18{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR and that of 'Damrojunggab' had no big difference above $12{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR. Desirable indicator to select individuals for the onion breeding is to select individuals that has low pyruvic acid content and high sweetness. Therefore, it will be possible to produce sweet onion conditioned on light supplement over $18{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR in 'Josaeng-ssundeobol' and over $12{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR in 'Damrojunggab'.

• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.64-70
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• 2005

To investigate the synergistic effects of low dose gamma irradiation and growth regulators on the growth and photosynthesis in rice (Oryza sativa L.), laboratory and greenhouse experiments were conducted using 4-year-old rice seeds. In the laboratory experiment, the germination rate was increased in 0.001 ppm IBA treatment, showing the synergistic effect of gamma irradiation and growth regulators. The seedling growth was increased by treatment of GA₃ and IBA, the irradiated groups having higher than the non-irradiated ones. Particularly, it was remarkable in 0.001 ppm IBA. In greenhouse experiment, seedling growth was increased in response to a combination of gamma irradiation and 0.001 ppm IBA. Effective quantum yield of PSⅡ(Ф/sub PSⅡ/) and photochemical quenching (qP) were increased, while non-photochemical quenching (qN) was decreased by 0.001 ppm IBA. A synergistic effect of gamma irradiation and IBA was only found in seedling growth. The present results suggest that low dose gamma irradiation and growth regulator could synergistically stimulate seedling growth.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.419-425
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• 2004

Two different groups (30 and 60 inds.) of olive flounder (Paralichthys olivaceus) were abruptly (within 30 min) exposed to hypo-salinities from seawater (SW, 35$\textperthousand$) to freshwater (FW, 0$\textperthousand$) (30FW and 60FW) and to 35$\textperthousand$ (30SW and 60SW) in a flow through seawater culture systems. Analysis of plasma samples showed the following significant increase at 0$\textperthousand$: cortisol from $2.8\;ng\;mL^{-1}$ to $66.9\;ng\;mL^{-1}$ (30FW) and from $2.7\;ng\;mL^{-1}$ to $314.1\;ng\;mL^{-1}$ (60FW) after 24 hours of exposure; glucose from $15.8\;mg\;dL^{-1}$ to $257.7\;mg\;dL^{-1}$ after 3 hours exposure and to $164.0\;mg\;dL^{-1}$ after 24 hours in 60FW. Plasma $Na^+$ concentration of 30FW and 60FW were decreased until 24 hours after expose. However that in 30SW and 60SW showed no significant differences. Plasma $Cl^-$ concentration of 60FW was decreased from $59.0\;mEq\;L^{-1}$ to $43.5\;mEq\;L^{-1}$ and to $30.0\;mEq\;L^{-1}$ after 3 and 24 hours of exposure, respectively. At all experimental groups, survival were 100% until 24 hours.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.478-485
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• 2013

Fish field survey, especially fish distribution and their ecological characteristics, was performed in the downstream region of Gyeongan stream during the period of before (June) and after (October) the summer monsoon in 2010. Depending on the characteristics of each site, fyke net or casting net was used for fish sampling. Feeding classification was determined by the analysis of stomach contents. Total number of family and species sampled were 5 and 17, respectively. The dominant family was Cyprinidae (12 species), and relative abundance (RA) of the most dominant species, Lepomis macrochirus and Zacco platypus, was 38% and 24%, respectively. Exotic species and Korean endemic species observed were 3 (423 individuals, RA 44%) and 4 (98 individuals, RA 10%), respectively. Tolerance guild analysis as characteristics of ecological indicators revealed an undoubtedly high percentage (97%), compared to others as reflected by the identification of just one sensitive species. Analysis of trophic guilds showed that L. macrochirus dominated among insectivores (44% RA). The food of L. macrochirus composed of, aquatic insects, benthic invertebrates, zooplankton, Chironomidae, and waterweed. Thus, we determined that L. macrochirus could be classified as insectivores (partially carnivores) in this study. Conversely, Z. platypus consumed Cladocera exclusively, greater than 90% of their feed. We presume that stable isotope analysis would identify the exact position of these species in the food web.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.695-701
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• 2009

This study was performed to evaluate the effectiveness of biological critical control points using the genetic profile of Escherichia coli isolates from pork cutting plants. Samples were collected from carcasses, equipment (knife, table, glove, transport belt, boning and skinning machine), the environment (wall and floor), and meat cuts during the cutting process from two plants. Pulsed-field gel electrophoresis (PFGE) was used to characterize the E. coli isolates. An identical genotype was detected from the carcasses, equipment, environment, and final meat cuts, and showed that the incoming carcasses, which were contaminated during transportation from slaughterhouses, were a major source of E. coli that was spread throughout processing. Also, consistent cross-contamination due to improper cleaning and disinfection procedures was another possibility. As a result, incoming carcasses and cleaning procedures should be considered critical control points in pork cutting plants, since a heating step is not used to inactivate microorganisms. Furthermore, the high rate (59.6%) of E. coli isolation indicates E. coli can be a good indicator in livestock processing plants even though it has genetic diversity.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.257-264
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• 2017

Pseudomonas veronii MS1 and P. migulae MS2 have several mechanisms of copper resistance and plant growth promoting capability, and also can alleviate abiotic stress in plant by hydrolysis of a precursor of stress ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC) by ACC deaminase. In 4-week pot test for tomato growth in soil contained 700 mg/kg Cu, inoculation of MS1 and MS2 significantly increased root and shoot lengths, wet weight and dry weight of tomato plants compared to those of uninoculated control. The inoculated tomato plants contained less amounts of proline that can protect plants from abiotic stress, and malondialdehyde, an oxidative stress marker than those of control. ACC synthase genes, ACS4 and ACS6, and ACC oxidase genes, ACO1 and ACO4, both involved in ethylene synthesis, were strongly expressed in Cu stressed tomato, whereas significantly reduced in tomato inoculated with MS1 and MS2. Also, a gene encoding a metal binding protein metallothionein, MT2 showed similar expression pattern with above genes. All these results indicated that these rhizobacteria could confer Cu resistance to tomato plant under Cu stress and allowed a lower level of Cu stress and growth promotion.

• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.553-563
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• 2006

This study aims to produce land-cover maps of Korean peninsula using multi-temporal MODIS (Moderate Resolution Imaging Spectroradiometer) imagery. To solve the low spatial resolution of MODIS data and enhance classification accuracy, Linear Spectral Mixture Analysis (LSMA) was employed. LSMA allowed to determine the fraction of each surface type in a pixel and develop vegetation, soil and water fraction images. To eliminate clouds, MVC (Maximum Value Composite) was utilized for vegetation fraction and MinVC (Minimum Value Composite) for soil fraction image respectively. With these images, using ISODATA unsupervised classifier, southern part of Korean peninsula was classified to low and mid level land-cover classes. The results showed that vegetation and soil fraction images reflected phenological characteristics of Korean peninsula. Paddy fields and forest could be easily detected in spring and summer data of the entire peninsula and arable land in North Korea. Secondly, in low level land-cover classification, overall accuracy was 79.94% and Kappa value was 0.70. Classification accuracy of forest (88.12%) and paddy field (85.45%) was higher than that of barren land (60.71%) and grassland (57.14%). In midlevel classification, forest class was sub-divided into deciduous and conifers and field class was sub-divided into paddy and field classes. In mid level, overall accuracy was 82.02% and Kappa value was 0.6986. Classification accuracy of deciduous (86.96%) and paddy (85.38%) were higher than that of conifers (62.50%) and field (77.08%).