• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.371-376
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• 2014

A Study on zooplankton fauna and phytoplankton flora was carried out three times in June, August and September 2012 at the Hyuncheon wetland in Gangwon-do, Korea. A total of 14 taxa of zooplankton were distributed, which consisted of six rotifers, four cladocerans, two copepods, one nematode and one aquatic insect larvae. Occurrence of Simulium japonicum supports that studied water is the first grade clear water. It was observed that the abundance of zooplankton was never exceeded over $55ind.L^{-1}$. Rotifers dominated in the months of June and August, whereas cladocerans in September, respectively. The phytoplankton flora was consisted of 26 species. The standing crops varied between $4,080{\sim}10,120cell.L^{-1}$. Docidium undulatum is the typical species distributed in muddy wetland and Closterium acerosum is distributed widely from wetlands through lakes. Navicula spp. and Nitzchia spp. were recorded to be distributed in lentic waters of big lakes such as Paldang Lake. Species diversity indices decreased gradually from June to September between 1.3~1.9 in zooplankton but lowest in August between 0.9~1.6 in phytoplankton, respectively. Based on my study observation, I anticipate that the poor distribution of zooplankton, phytoplankton, and low values of species diversity index are likely to be a cause of narrow area with shallowness of waters during the short period.

• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.16-25
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• 2015

This research was conducted to analyze flavonoids in juice and to investigate correlation between 60 germplasms of satsuma mandarin (Citrus unshiu Marc.) on the basis of the result of flavonoid analysis. Juice of satsuma mandarin contained 6 flavonoids, 2 flavanones such as narirutin and hesperidin, 1 flavone such as rutin and 3 polymethoxylated flavones such as sinensetin, tangeretin and nobiletin. Hesperidin content ranged from 41 to 196 mg/L. Narirutin content ranged from 25 to 230 mg/L. The average of rutin content was 2.2 mg/L but it was not detected in some cultivars. Polymethoxylated flavone which is known as a citrus specific flavonoid, was detected in all germplasms in small quantities. Cluster analysis using R program (Version 3.1.1) was carried out with the results of the flavonoid analysis and harvesting time of satsuma mandarin germplasms. All germplasms were grouped as A, B1 or B2. But all 3 groups contained very early-ripening type, early-ripening type and commonly-ripening type cultivars. This showed there was no correlation between flavonoids in juce and their harvest time.

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.601-613
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• 2011

The purpose of this study is to provide an protected wildlife species and potential habitats in Seoul through the overall present status of the species which live in Seoul. This study was performed in Seoul, the entire area of which is 605.52 $km^2$. We analyzed a total of 57 studies, including academic papers and research reports, for the natural ecology in Seoul. As for the results from the study, it was found that a total 1,907 species from 5 taxa were inhabiting and growing within the area. Among the total, plants of 1,656 species accounted for 86.7%, 197 species of wild birds made up 10.3%, 29 species of amphibians and reptiles consisted of 1.5%, and 27 species of mammalia totaled 1.4%. A total of 440 species except foreign species and species legally preserved by the Ministry of Environment, common species and uncertain species were selected as primary candidates. By taxon, it shows 212 species of plants, 180 species of wild birds, 24 species of mammalia, and 24 species of amphibians and reptiles. For extensive research subjects and research data limited in certain insect family, analysis by literature for discovered insects was excluded. The selection criteria for the second candidate species was based on extinction crisis, rarity, historicity and locality, academic value, habitat specificity, etc. The second candidate species from the primary species were selected through taxon experts' evaluations. As for the results of the selection of the second candidates, a total 77 species were selected through the experts' evaluations. Each species by taxon was 25 species for plants, 21 species for wild birds, 5 for mammalia, 10 for amphibians and reptiles and 16 species for insects. A site investigation for the second candidates was conducted to select the final candidate species. For the target areas, the habitats of the second candidates given by the literature and 46 potential areas in Seoul, which show good natural resistance, were finally selected. From the result of the site investigation, it was found that 14 species of plants, 19 species of wild birds, 2 species of mammalia, 4 species of amphibians and reptiles, and 16 species of insects were actually inhabiting Seoul; thus, the final 55 protected species were selected.

• Korean Journal of Environmental Agriculture
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• v.14 no.3
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• pp.329-337
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• 1995

The effect of N-(4-chlorophenyl) maleimide(CPMI), plant growth regulators, and alkylating agents on gluathione(GSH) content and glutathione S-transferase(GST) activity was examined with 3-day-old etiolated sorghum(Sorghum bicolor [L.] Moench) seedlings. The GSH content and GST activity of untreated seedlings were higher in shoots than that in roots. Response of GST activity in coleoptile was significantly greater than in other tissues of sorghum seedling. In CPMI-treated seedlings, GSH content was not significantly different from that in untreated seedlings. CPM treatment resulted in 2.3-fold increase in GST activity measured with metolachlor as substrate in the coleoptile region. In contrast, change in GST activity measured with metolachlor as substrate in the coleoptile region. In contrast, change in GST activity measured with 1-chloro-2, 4-dinitrobenzene did not occur. The increase of GST activity was caused by induction of a GST isozyme, which is substrate-specific to metolachlor. Subsequently, two hypotheses related to metolachlor detoxification were evaluated on the basis of regulation of plant growth regulators and substrate induction of GST activity. In coleoptile, GST activity measured with metolachior was increased to 2.1-and 3.4-fold by both 2, 4-dichlorophenoxyacetic acid(2,4-D) and metolachlor treated at the germination stage of sorghum, respectively. Treatments of 2.4-D and metolachlor also induced isozymes exhibiting the activity toward metolachlor. One of the isozymes was co-eluted with that induced by CPMI. These results indicated that increase in GST activity by CPMI may be partially related to auxin regulation and substrate induction.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.158-165
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• 2003

This study was conducted to reveal the role of meteorological elements on the habitat characteristics and vegetative structure for S. commixta natural populations at Ulleung Island. Potential Evapotranspiration(PET) by elevation of Ulleung Island was estimated using Thornthwaite's climatology estimating method. Also, Warm Index (WI), Coldness Index (CI) and vegetative composition by elevation were determined. The following results were obtained: The S. commixta trees wire mainly distributed from an elevation of 300 m to 900 m. The WI and CI were about 66.8∼95.0, -21.5∼-7.7, respectively. Water deficit by precipitation and Potential Evapotranspiration (PET) mainly occurred from March to October at all elevations. But wafer deficits diminished with increased elevation. The apparent species in S. commixta natural populations at Ulleung Island were: 10 tree layer species, 17 subtree layer species, and 25 species in the shrub layer. In the tree layer, S. commixta was dominant with the highest value of 46.85, then Fagus crenate 13.43, Acer mono and Tilia amurensis 12.41 and 12.03, respectively. In the subtree layer, A. mono was dominant with the highest value of 13.16, then F. crenata 12.68, Acer pseudo-sieboldianum and S. commixta 11.37 and 10.76, respectively. Dominant species and IV values in the shrub layer were Sasa borealis (22.09) and Rhododendron brachycarpum (10.51). The S. commixta natural forests were in a relatively stable rendition because of the even distribution of its various indexes: the species diversity index of Shannon, the evenness index and dominance were 0.6199∼1.1390, 0.6199∼0.8825 and 0.1852∼0.3801, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.49-54
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• 1970

In an effort of determine the metabolism and bio-synthesis of nitrogen, was studied at variance of souble nitrogens, free amino acids and total alcohol soluble amino acids during the growth of younger soybean plants, and saybean divides into cotyledon and embryonic organ (shoot and root system) in this experiment. 1. In the soluble nitrogen of soybean, ratio of increase and decrease in the amino acids of them was displayed the near phenomena both cotyledon and embryonic organ of soybean. But, in the 17th days after seed germination, that is the developmeatal stage of adult leaf of soybeans, was appear the maximum value. It has been suggested that the stage of first half period of growth as boundary the stage of adult leaf development which indicated clear morphologically, at the younger soybean plants, is the step that nitrogen assimilation. 2. It was investigated the amino acids of seventeen kinds in the seed state, but at the third days after seed germination, was investigated the amino acids of nineteen kinds. Ultimately, it appears the translocation from cotyledon to embryonic organ in the distribution of amino acid, the nineth day which differentiation begining day of embryonic organ, then after, it happen the variation of number of inspected amino acid in the cotyledon and embryonic organ but only the variance changes in the distribution and quantitative aspects. Especially, the most conspicuous fact was indicated the accumulation of Asparagine, that is the phenomena of Asparagine-accumulation was constitute, not with standing no fertilization from outside. It may be concluded from the results of this investigation that the difference of special phenomena of soybean from the embryo of other plans. 3. In the initial stage of differentiation at embryonic organ number of inspected amino acid was very few, and then, it was slightly appeared the increase-phenomena in the number of them. It was that the amino acid inspecting the initial stage was translocated from the cotyledon. It is suggested that the intermediate-metabolism of amino acid was constituted on the basis of above the result. 4. The phenomena of increase and decrease of total alcohol soluble amino acid were essentially identical to the water soluble amino acid of soybean, but it was appeared the severe difference of amounts in both of them.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.564-577
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• 2017

We investigated whether external environmental factors acted as a trigger for flowering in the draft bamboo (Sasa borealis (Hack.) Makino) blooming area of Mt. Baekwoon located in Gwangyang, South Jeolla Province. We then considered the cause for flowering, flowering patterns and life history strategies of the draft bamboo based on the investigation. There were no differences in soil, physical conditions, and light amount between the draft bamboo flowering and non-flowering areas. The precipitation and temperature of the areas in Korea and Japan where it blossomed from 2014 to 2017 were similar to the normal year values (for the past 30 years). Moreover, most of the draft bamboo died after flowering on a large scale, but some did not, or some culms were developed again. In other words, the draft bamboo bloomed simultaneously regardless of external environmental factors, and most of the culms were dead, but some were left alive. Therefore, it is considered that the flowering is triggered by the specific genes (referred as to clock genes) expressed periodically by a biological clock rather than the external environmental factors. Meanwhile, the draft bamboos generally bloom on a large scale by synchronizing with other ones in the distance but may also bloom several times separately on a small scale. It may be a kind of an insurance system established to disperse the risk of failed sexual propagation when flowering once in a lifetime. The results reveal that the long-period monocarpy of the draft bamboo has been strengthened to optimize the sexual propagation to overcome the increased environmental instability caused by the expansion of distribution of tropical bamboos and bamboo species to the temperate regions.

• Korean Journal of Weed Science
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• v.9 no.1
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• pp.46-55
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• 1989

Stomatal variation was observed at the Yeongnam Crop Experiment Station in 1988 using 42 rice cultivars and 30 weed species. The shape, density or size of stomata was varied depending on the species. Two general trends, however, were found that more number of stomata was found at lower leaf epidermis than upper leaf epidermis and stomata number was negatively correlated with stomata size. Aneilema japonica and Portulaca oleracea had the least number of stomata having 17-20 stomata per $m^2$ for upper leaf epidermis and 17-54 stomata for lower leaf epidermis while Polygonum conspicuum had the greatest number of stomata (449 for upper leaf epidermis and 511 for lower leaf epidermis). Soybean, Aeschynomene indica, Ludwigia prostrata and Lactuca indica had the smallest in stomata size while the biggest stomata was found at P. oleracea and A. Japonica that had the least number of stomata. Cyperus species such as C. difformis, C. iria and C. serotinus had no stomata at upper leaf epidermis. The stomata were distributed only at lower leaf epidermis for these species. Potamogeton distinctus, on the other hand, had stomata almost at upper leaf epidermis and thus, hardly found the stomata at lower leaf epidermis. Among rice cultivars, Tongil-type had the greatest number of stomata followed by Indica-type and Japonica-type, in order. Cultivars released after 1960 had more stomata than cultivars released before 1960 for Japonica-type cultivars while stomata size had reversed trend. Jinheung had the least number of stomata (${\fallingdotseq}$ 150 per $mm^2$) while Yushin had the greatest number of stomata (350 for upper and 449 for lower leaf epidermis, respectively) among rice cultivars. Other cultivars having more than 350 stomata per $mm^2$ were Samgangbyeo, Milyang 23, Woonbongbyeo, etc.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.603-613
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• 1996

Hydrographic conditions (temperature, salinity, dissolved oxygen), nutrients, chlorophyll-a and suspended solid have been studied in the southwestern coastal area of Cheju Island from April 1993 to March 1994. Vertical profile of temperature, salinity and chemical properties (nutrients, chlorophyll-a) distribution in th southwestern sea of Cheju Island showed a upwelling feature. Although it was not clear in winter season, it seems to continued through out the year. In the surface water at the upwelling areas, the ranges of dissolved oxygen, nitrate, phosphate and silicate was $3.30\~8.43\;ml/l,\;0\~7.12{\mu}g/l,\;0.03\~1.75{\mu}g-at/l\;and\;2.75\~22.32\;{\mu}g-at/l$l, respectively. Nutrients was higher in the shore water than in the offshore water, because sufficient supply of nutrients from the bottom water by coastal upwelling. In November, especially high concentration silicate was observed at all the stations and depth in the study area. At all station of bottom water (down to the depth of 60 meter), concentration value of dissolved of gen was as high as 8 ml/l. Mean values of N/P was 8.0, lower than Redifield ratio of 16. The mean values of Si/P was observed to 46.3 in southwest of Cheju Island. Concentration of chlorophyll-a was in the range of $0.04\~2.36\;{\mu}g/l$. Concentration of chlorophyll-a in surface orator at all station was especially higher in spring than in other seasons. Mean concentration value of suspended solids was 3.14 mg/l $(0.75\~8.47\;mg/l)$. Ratio of the volatile suspended solids to the suspended solids was higher in the inshore water $(53\%)$ than in the offshore water $(46\%)$, and higher in the surface water than in the bottom water.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.54-71
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• 1991

To classify and analyze the forest communities and their structures, the vegetation in Mt. Joghe was investigated from July, 1980 to August, 1989. The results obtained are as follow ; 1. A total of 750 kinds of vascular plant(49 orders, 122 families, 434 genera, 627 species, 1 subspecies, 111 varieties and 11 forma)were observed in Mt. Ioghe. The newly observed plant species were Dioscorea quingueloba, Spiranthes sinensis, Cephalanthera falcata, Angelica gigas, Clematis patents, Paeonia obovata, Hibiscus mulabilis, Ainsliaea acerifolia, Dictamnus dasycarpus, Cynachum ascyrifolia, Vaccinium koreanum, Erythrortium japonicum, Indigofera kirilowii (17species), Broussonetia kazinoki var, humillis, Euonymus, fortunei var. radicans, Juniperus communis var, nippnnica, Callicarpa japonica var. radicans, Joniperus communis var. rzipponica, Callicarpa japonica var. taquetii (4 varieties) and L indera obtusiloba for. billosum (1 forma). 2. The life spectrum of flora in Mt. Joghe was classified into $CH-D_1-R_5-e$ type. Distribution area was identical to Southern type by Nakai, Lee, and Yim. A few subtropical species were also observed. 3. Simpson's species diversity index(Ds) was 0.9 and Shannon-Weiner's diversity index (H') was 1.004. These indice suggest that the vegetation in Mt. Joghe is of complicated forest communities. 4. Pte-Q was 1.81 which was higher than the nationwide mean of 1.68. Urbanization Index (UI) was 28.75 for naturalized plant species, and 17.49 for exotic woody plant species, which were similar to those of Mt. Baekun and Mt. Naejang. 5. The forest vegetation of Mt. Joghe was grouped in 3 vegetation types : 7 natural plant Communities dominated by Quercus serrat, Quercus acutissima, Quercus variabilis, Carpinus laxiflora, Pinus derasiflora and Platycarya strobilacea, 8 substitutional plant communities Styrax japonica, Stewartia koreana, Lindera erytlrrocarpa, Zelkova serrata, Rhtrs chinensis, Controversa, and Frzrxirtus manrlshurica, and 7 plantation Communities composed of Pinus koraiensis, Pinus rigida, Magnolia nbnvata, Chamecyparis obkrsa, Larie ieptolepis, Castanea crenata and Cryptomeria japonica. 6. Actual vegetation maps and profile diagrams were made by phytosocialogical classification. 7. As the important and unique species in Mt. Joghe, Lindera sericea, Penicaria tilitorme, Hex macropoda, Hex macropoda for. pseudo-macropoda, Steroartia koreana, Adenopkora palustris and Corylop.,is coreana, which were also seported by Lee(1977), Kim and Yark(1989), were identified and Vaccinium coreanum, Cremastra appendiculinium, Juniperus comminis van. nipponica, Cephalanthera falcata, Broussortetia kazinoki var. humilis, paeonia obovata, Deutzia prunifolia, Dictamnus dasyarpus, Angelica gigics and Bupleurum falcatum were odditionally observed.