• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.3
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• pp.124-131
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• 2008

This study was conducted around the southwest sea areas of Jeju and coastal sea areas of China in August 2003 and September 2004 to research distribution patterns of dissolved inorganic nutrients, dissolved and particulate organic carbon. Distribution patterns of nutrients in the East China Sea in summer were shown to be influenced by water masses and phytoplankton. Water masses in the East China Sea in summer, except for coastal sea areas of china, showed less vertical mixing process, causing decline in the inflow of nutrients to surface water. Bottom water, however, showed high concentration, since nutrients made by dissolved organic matters from surface water were accumulated at the bottom. Sea areas with high concentration of chlorophyll a showed low concentration of nutrients and vice versa, indicating biological activities control dissolved inorganic nutrients. The distribution of dissolved organic carbon didn't show any correlation with salinity, temperatures, and water masses. Areas around the river mouth of the Changjiang showed high concentration of dissolved organic carbon more than $100{\mu}M$, but relatively low concentration in the southwest sea areas of Jeju, indicating that the river mouth of the Changjiang coastal water has a great influence on dissolved organic carbon in the East China Sea. Distribution patterns of particulate organic carbon in the research areas showed the highest concentration of average $9.23{\mu}M$ in coastal areas of China influenced by the river mouth of the Changjiang coastal water. By comparison, the concentration was relatively low at $3.04{\mu}M$ in the southeast sea areas of Jeju on which the Taiwan warm current has influence, and was $7.23{\mu}M$ in the central sea areas of Jeju. Thus, there is much indication that the river mouth of the Changjiang coastal water serves as a supplier of particulate organic carbon along with autogenous source. In general, if particulate organic carbon has a high correlation with the concentration of Chlorophyll a, it is thought that it is originated from autogenous source. However, the southeast sea areas of Jeju shows low salinity below 30, therefore it is proper to think that its origin is terrestrial source rather than that of autogenesis.

• Journal of the Mineralogical Society of Korea
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• v.22 no.1
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• pp.1-11
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• 2009

Fine-grained peridotite xenoliths are rarely trapped in the basaltic rocks from the southeastern part of Jeju Island. Based on textural characteristics of the constituent phases showing uniform-sized, fine-grained tabular to mosaic grains with rare porphyroclastic relics, the studied samples can be defined as fine-grained, foliated porphyroclastic peridotites (FPP). Almost no significant difference among the FPPs in textures and major element compositions implies that the FPPs were derived from a structural domain, experiencing similar deformation events and deformation patterns. Moreover, the bimodal distribution with kink-banded porphyroclasts ($2{\sim}3mm$) and stain-free neoblasts ($200{\sim}300{\mu}m$), straight to gently curved grain boundaries with triple junctions, interstitial melt pockets, and microstructures for migrating grain boundary suggest that the studied samples went through dynamic recrystallization (${\pm}$ static recrystallization) in the presence of melt/fluid movement along foliation planes. No notable difference between the FPP and common protogranular xenoliths in major element compositions and geochemical evolution also implies that the FPP and protogranular xenoliths were from a similar horizon. Thus, the textural and geochemical characteristics of the FPPs reflects deformation events occurred at a localized and narrow zone within the lithospheric mantle beneath the Jeju Island. Although further detailed studies are necessary to define deformation events, the most possible process which could trigger deformation in the FPP in the rigid upper mantle was the ascending basaltic magma forming high-stress deformation zones. The suggested high-stress deformation zones in the lithosphere beneath the Jeju Island may be produced by paleo-faulting events related to the ascent of basalt magma before Jeju Island was formed.

• Journal of Aquaculture
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• v.5 no.1
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• pp.93-108
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• 1992

This study was conducted to understand the variation of suspended matters in coastal waters of Cheju Island. Water sampling was carried out at 22 stations along the coast of this island from March 1988 to November 1989. Analyzed and/or observed items were water temperature, salinity, total solids (TS), total dissolved solids (TDS), volatile suspended solids (VSS), and fixed suspended solids (FSS). Inter-relationships between wind velocity, precipitation and total suspended solids (TSS) were also investigated. More windy days prevail in winter season (December, January and February) in Cheju Island. Thirty-six points seven percent of total windy days of a year appeared in this season. The rate of windy days in spring was $27.3\%$ and those in summer and fall were $17.9{\%}$ each. From February to July, the heaviest precipitation was observed in the southeastern area and that from August to January was observed in the eastern part of this island. TS and TDS were firmly related with the fluctuation of salinity. Therefore, there were higher in spring and lower in summer. The highest TSS (7.73 $mg/{\ell}$) was observed in February and was the lowest (4.73 $mg/{\ell}$) in September. Annual mean value of TSS was 6.3$mg/{\ell}$. The highest VSS (2.03 $mg/{\ell}$) was observed in July and lowest (1.42 $mg/{\ell}$) in September. The percentage of VSS per 755 was $30.6{\%}$ in average that was not much higher level compared to the other polluted areas. This value became higher in summer (av. $34.17{\%}$) and lower in winter (av. $24.2{\%}$). Fluctuation of TSS was mainly related with the freshwate. discharge, tidal action, and re-suspension of bottom sediments by the wind waves. Therefore, TSS concentration was low in summer and hish in winter.

• Korean Journal of Ecology and Environment
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• v.49 no.1
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• pp.11-21
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• 2016

Cymbidium kanran Makino is being threatened in its own habitats due illegal collecting and habitat changes by vegetation growth along historical landuse change. In this study, we established habitat restoration model for conservation of C. kanran based on ecological diagnosis. Through exploration to Jeju Island in 2014 and 2015, we identified 27 unknown habitats of C. kanran and in there, abiotic variables and vegetation structure and composition were quantified. Altitudinal distribution of C. kanran was between 200 m~700 m a.s.l. and compared to distribution in 2004, Area of Occupation (AOO) decreased at 82%. Specific habitat affinity was not observed by evenly found in mountain slope and valley and summergreen and evergreen broadleaved forests, but likely more abundant in valley habitats with higher soil and ambient moisture. Total of 96 individual of C. kanran was observed with an average density of $942.6individuals\;ha^{-1}$. The plants showed relatively short leaf length (average=$10.7cm{\pm}1.1cm$) and small number of pseudo bulbs ($1.2{\pm}0.2$). Flowering and fruiting individuals were not observed in field. C. kanran was classified into endangered plant species as CR (Critically Endangered) category by IUCN criteria. Phenotypic plasticity of C. kanran was likely support to sustain in more shaded habitat environment and recent habatat changes to closed canopy and low light availability may exhibit negatively effects to C. kanran's life history. Restoring C. kanran habitat should create open environment as grassland and low woody species density.

• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.186-193
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• 2014

This study aimed to analyze spatio-temporal trends of phenological characteristics in South Korea by using MODIS EVI. For the phenology analysis, we had applied double logistic function to MODIS time-series data. Our results showed that starting date of phenology seems to have a tendency along with latitudinal trends. Starting date of phenology of Jeju Island and Mt. Sobeak went back for 0.38, 0.174 days per year, respectively whereas, Mt. Jiri and Mt. Seolak went forward for 0.32 days, 0.239 days and 0.119 days, respectively. Our results exhibited the fluctuation of plant phonological season rather than the change of phonological timing and season. Starting date of plant phenology by spatial distribution revealed tendency that starting date of mountain area was late, and basin and south foot of mountain was fast. In urban ares such as Seoul metropolitan, Masan, Changwon, Milyang, Daegu and Jeju, the phonological starting date went forward quickly. Pheonoligcal attributes such as starting date and leaf fall in urban areas likely being affected from heat island effect and related warming. Our study expressed that local and regional monitoring on phonological events and changes in Korea would be possible through MODIS data.

• The Korean Journal of Malacology
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• v.28 no.3
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• pp.197-213
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• 2012

This study was performed to know the community structure of macrobenthos and environmental factors at each 16 stations in the subtidal sandy bottoms of the southern coastal water of Jeju Island from July to November, 2011. Mean temperature and mean salinity were $20.2-22.7^{\circ}C$, 33.7-34.9 psu which shows stable water messes. Chlorophyll a concentrations of phytoplankton ranged from 0.71 to 1.71 mg/L (1.11 mg/L), showing higher July than September and November with a blooming in summer. The mean concentration values (the ranges in parentheses) of nitrate, phosphate, and silicate are 0.029-0.206 mg/L (0.101 mg/L), 0.001-0.027 mg/L (0.007 mg/L), 0.024-0.682 mg/L (0.454 mg/L), respectively. However, the values higher coastal zone due to influxes from the land. A total of 37 species was identified. of these mollusca comprised 29 secies (78.4%); Echinodermata 5 (13.5%); Arthropoda 3 (8.1%). density and biomass were estimated to be 550 ind./$m^2$ and 20,951.8 gwwt/$m^2$, respectively. Mollusca were the most dominant faunal group in terms of abundance (481 ind./$m^2$) and number of species as well, whereas bivalves were predominant in biomass (16,647.6 gwwt/$m^2$). The dominant species were Vasticardium burchardi, Oblimopa japonica, Mactar achatina, Bornatemishistrioiw akawai, Paphia vernicosa, Amusium japonicum, Glycymeris albolineata, Astriclypeus manni in 15-30 m. The seasonal variation appeared as distinct, Mollusca of individual and biomass. When summer was make a slow increase, after the highest decrease in autumn. The abundance of macrobenthic invertebrates showed significant correlation with environmental factors (Chlorophyll a, DIN, $SiO_2$, Fine sand, Very fine sand) in almost all sampling depths. The biodiversity, evenness richness index were appeared 1.56-2.50 (H'), 0.49-0.80 (E'), 4.12-4.67 (R) in each stations. The dominace index were appeared Highest in November and lowest in September.

• Korean Journal of Plant Resources
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• v.21 no.1
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• pp.1-4
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• 2008

The clonal variation in female flowering was studied in Larix leptolepis clone bank, consisting of 116 clones, for three years. The between-year variation was large; i.e. the percentage of flowering grafts and average number of flowering per graft were $28.4{\sim}67.2$ and $9{\sim}176$, respectively. Differences in flowering abundance among clones were large and statistically significant in all the years studied. The variance of flowering abundance among clones was increased when flowering was poor. The average of broad-sense heritability of flowering abundance was 0.52. The genetic gain(%G) was estimated at 57.4% when the upper 30% clones were selected. The clonal stability of flowering abundance was compared using average number of flowering and coefficient of variance value of each clone. The clones such as Gyeonggi 9(29), Kangwon 37(137), Chungnam 6(46), Chungnam 14(414), R11, R8 showed abundant flowering and high stability.

• Applied Biological Chemistry
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• v.24 no.4
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• pp.224-229
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• 1981

Perilla (Perilla frutescens Britton var. Crispa Decasne) cultivated in three geographical areas of Korea, Gwangju, Taegu and Jeju, was analyzed for carbohydrate, lipid, protein, inorganic components and fatty acid composition. Carbohydrate, lipid and protein content of perilla seed ranged from 40 (Taegu) to 44% (Jelu), from 28 (Jeju) to 34% (Taegu) and from 15 (Gwangju) to 16% (Jeju), respectively. The overage contents of potassium, silicate, calcium, phosphate, iron, zinc, magnesium and mangane in the perilla seed varied between $426{\sim}446$, $197{\sim}229$. $124{\sim}136$, $46{\sim}56$, $30{\sim}49$, $42{\sim}45$, $40{\sim}45$, and $30{\sim}36mg%$, respectively and those variations different cultivation areas were not significant except iron. Saponification number, iodine value and acid value of the perilla oil were between $194{\sim}198$, $196{\sim}200$ and $4{\sim}5$, respectively. Those variations among the cultivation areas were not significant. The composition of the perilla oil was observed to be composed of $92{\sim}95%$ of triglyceride, $1.2{\sim}1.3%$ of phospholipid, $1.7{\sim}1.9%$ of unsaponifiables, $0.7{\sim}0.9%$ of free fatty acid, and $1.1{\sim}1.4$ linolenic, linoleic and oleic acid as $55{\sim}56$, $16{\sim}18$ and $16{\sim}20%$ of total fatty acids, but in phospholipid, the content of saturated fatty acids, $12{\sim}24$ of total fatty acid, was higher than that in triglyceride, $8{\sim}19%$ of total fatty acids. The content of saturated fatty acids in sterylester $(14{\sim}19%)$ was higher than that in sterylglycoside ($6{\sim}7%$ of total fatty acids). The variation in fatty acid composition was not significant in the composition of total fatty acid but a significant difference was observed in the composition of phospholipid, in which the content of palmitate ranged from 11.8%(Taegu) to 24%(Gwangju) of total fatty acids. No significant variation was found in the fatty acid composition among the cultivation areas, while a significant difference was observed in phospholipid.

• Journal of Life Science
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• v.27 no.3
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• pp.295-300
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• 2017

This study examined the association between genotypes of the isocitrate dehydrogenase 3, beta subunit (IDH3B) gene and economic traits in an $F_2$ population of Duroc and Jeju (South Korea) native black pigs (JBPs). The genotypes was determined the presence/absence of a 304-bp insertion/deletion fragment in the promoter region of the IDH3B gene for JBP, Duroc, and their $F_1$ and $F_2$ progeny. Three genotypes (AA, AB and BB) were found in the $F_1$ and $F_2$ populations, but there was no AA genotype found in JBP and no BB in Duroc. Association analysis results showed the significant differences with carcass weights (CW), backfat thicknesses (BFT) and eye muscle area (EMA) (p<0.05), but not with growth traits including body weights and average daily gains at different stages, reproductive traits including teat numbers, and crude fat contents (CFAT) measured in longissimus dorsi (p>0.05). The $F_2$ pigs possessing the IDH3B BB homozygote had heavier CW ($72.92{\pm}11.133kg$), thicker BFT ($25.75{\pm}6.06mm$), and larger EMA ($23.82{\pm}4.825cm^2$) than those from the other genotypes (p<0.05). These results were estimated that there are biological roles related with IDH3B genotypes resulting development of EMA, BFT, and CW but not with intramuscular fat deposition during late period of pig production. Our findings suggest that the 304-bp insertion allele of porcine IDH3B may be a genetic marker for marker assistant selection for improving meat productivity of the Jeju Black pig and Duroc-related molecular breeding systems.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.98-104
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• 1999

To investigate the relationships between ocean environmental characteristics, the time-series data of temperature and salinity observed at a station near at Hanlim set net in 1995 and 1996 are analyzed, and the results are as follow ; 1. In hanlim set net, the diurnal range of temperature and salinity variation in summer is very large and the amplitude of short-period fluctuation of temperature and salinity is very large. That is, not only the water of the middle and bottom layers (low temperature and high salinity) but also the coalstal water (high temperature and low salinity) appears alternatively depending on the current direction 2. from the result of mooring for 22 days in Hanlim set net, the mean speed and direction of tidal current in neap tide were 9.1 cm/sec and south westward in ebb time, and 11.6 cm/sec and north or northeastward in flood time, respectively. The highest speed of the current was 15cm/sec in ebb time, and 22.6 cm/sec in flood time. The mean speed and direction of tidal current in spring tide were 10.4 cm/sec, and southwestward in ebb time, and 12.3 cm/sec, and north or northestward in flood time, respectively. The highest speed of the current was 19.4 cm/sec in ebb time, and 20 cm/sec in flood time respectively. The mean speed of the current in flood time was larger than that in ebb time. The velocity vector along the major axis of semidiurnal tide ($M_2$) component was 1.5 times larger than that of diurnal tide ($K_1$), The major directions of two compornants were northwestward and east-southeastward and residiual current were 3.25 cm/sec and northwestward-directed. Result of TGPS Buoy tracer for 3 days between Biyang-Do and Chgui-Do showed that the mean speed was 1.6 knot in ebb time and 1.3 knot in flood time. Direction of tidal was southwestward in ebb time and northeastward in flood time respectively. The maximum current speed was 4.8 knot in ebb time and 3.7 knot in flood time respectively. The mean speed and direction of tidal in of offshore were 1.7 knot and northwestward in flood time. The residual current appeared 0.3 knot northeastward.