• Title/Summary/Keyword: Dok-do Islands

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Characteristics of Precipitation and Temperature at Ulleung-do and Dok-do, Korea for Recent Four Years(2005~2008) (최근 4년간(2005~2008) 울릉도와 독도의 강수 및 기온 특성)

  • Lee, Young-Gon;Kim, Baek-Jo;Park, Gil-Un;Ahn, Bo-Young
    • Journal of Environmental Science International
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    • v.19 no.9
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    • pp.1109-1118
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    • 2010
  • Characteristics of precipitation and temperature in Ulleung-do and Dok-do were analyzed with hourly accumulated precipitation and mean temperature data obtained from Automatic Weather System(AWS) for latest four years(2005~2008). In Ulleung-do, total annual mean precipitation for this period is 1,574.4 mm, which shows larger amount than 1434.2 mm of whole Korean peninsula for latest 10 years(1999~2008) and 1,236.2 mm at Ulleung-do on common years(1971~2000), shows that the trend of precipitation gradually increases during the recent years. This amount is also 1.4 times larger than the total annual mean precipitation of 660.1 mm in Dok-do. Mean precipitation intensity(mm $h^{-1}$) at each time of a day in each month at Ulleung-do represents that the maximum values larger than $3.0\;mm\;h^{-1}$ were shown in May and on 0200 LST, whereas these were found in August and 0700 LST with $3.1\;mm\;h^{-1}$ in Dok-do. The difference of the precipitation amount and its intensity between Uleung-do and Dok-do is explained by the topological effect came from each covering area, and this fact is also identified from similar comparison of the precipitation characteristics for the islands in West Sea. The annual mean temperature of $14.0^{\circ}C$ in Dok-do is $1.2^{\circ}C$ higher than that of $12.8^{\circ}C$ in Ulleung-do. Trends of monthly mean temperature in both islands are shown to increase for the observed period.

Ages and Evolutions of the Volcanic Rocks from Ulleung-do and Dok-do (울릉도와 독도 화산암의 생성연대 및 진화사)

  • Song Yong-Sun;Park Maeng-Eon;Park Kye-Hun
    • The Journal of the Petrological Society of Korea
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    • v.15 no.2 s.44
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    • pp.72-80
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    • 2006
  • We report new K-Ar ages of volcanic rocks from Ulleung-do and Dok-do islands located at the middle of the Korea Sea; $3.67{\pm}0.40\sim1.89{\pm}0.29$ Ma for the Dok-do and $8.07{\pm}0.39\sim0.51{\pm}0.07$ Ma for the Ulleung-do. Such ages reveal that igneous activities of both Dok-do and Ulleung-do extend longer than previously reported. It is likely that igneous activity of Ulleung-do started as early as $8.07{\pm}0.39$ Ma which is much older than age known currently, and latest eruption and intrusion of trachyte of Dok-do lasted until $1.89{\pm}0.29$ Ma, which overlaps previously reported igneous activity of Ulleung-do. However, it seems that the main volcano-building stage of Ulleung-do started after 2.7 Ma and igneous activities of Dok-do were finished mostly before then, which suggests that Dok-do was farmed before Ulleung-do in the respect of main stages of volcano-building. Such explanation agrees well with the hypothesis that southeastern seamounts, Dok-do and Ulleung-do were sequentially generated by relatively fixed hotspot.

Microbacterium elymi sp. nov., Isolated from the Rhizospheric Soil of Elymus tsukushiensis, a Plant Native to the Dokdo Islands, Republic of Korea

  • Ye-Ji Hwang;Soo-Yeong Lee;Jin-Soo Son;Jin-suk Youn;Woong Lee;Jae-Ho Shin;Mi-Hwa Lee;Sa-Youl Ghim
    • Journal of Microbiology and Biotechnology
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    • v.33 no.2
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    • pp.188-194
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    • 2023
  • Microbacterium elymi KUDC0405T was isolated from the rhizosphere of Elymus tsukushiensis from the Dokdo Islands. The KUDC0405T strain was Gram-stain-positive, non-spore forming, non-motile, and facultatively anaerobic bacteria. Strain KUDC0405T was a rod-shaped bacterium with size dimensions of 0.3-0.4 × 0.7-0.8 ㎛. Based on 16S rRNA gene sequences, KUDC0405T was most closely related to Microbacterium bovistercoris NEAU-LLET (97.8%) and Microbacterium pseudoresistens CC-5209T (97.6%). The dDDH (digital DNA-DNA hybridization) values between KUDC0405T and M. bovistercoris NEAU-LLET and M. pseudoresistens CC-5209T were below 17.3% and 17.5%, respectively. The ANI (average nucleotide identity) values among strains KUDC0405T, M. bovistercoris NEAU-LLET, and M. pseudoresistens CC-5209T were 86.6% and 80.7%, respectively. The AAI (average amino acid identity) values were 64.66% and 64.97%, respectively, between KUDC0405T and its closest related type strains. The genome contained 3,596 CDCs, three rRNAs, 46 tRNAs, and three non-coding RNAs (ncRNAs). The genomic DNA GC content was 70.4%. The polar lipids included diphosphatydilglycerol, glycolipid, phosphatydilglycerol, and unknown phospholipid, and the major fatty acids were anteiso-C17:0 and iso-C16:0. Strain KUDC0405T contained MK-12 as the major menaquinone. Based on genotypic, phylogenetic, and phenotypic properties, strain KUDC0405T should be considered a novel species within the genus Microbacterium, for which we propose the name M. elymi sp. nov., and the type strain as KUDC0405T (=KCTC 49411T, =CGMCC1.18472T).

Morphological variation and aspects of the geographic distribution of Orobanche coerulescens Stephan ex Willd. (Orobanchaceae) on Ulleung-do and Dok-do Islands (울릉도, 독도 초종용에서 형태 변이와 지리적 분포 양상)

  • Lee, Woong;Jeong, Keum Seon;Choi, Kyung;Kim, Jin Seok;Cho, Seong Ho;Pak, Jae-Hong
    • Korean Journal of Plant Taxonomy
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    • v.46 no.4
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    • pp.405-412
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    • 2016
  • We investigate the intraspecific morphological variations and geographical distributions from twelve populations (28 samples) of Orobanche coerulescens in Korea. Two main morphological types were detected, i.e., glabrous (G-type) and pilose (P-type), in the external morphology (stem, leaf, bract, calyx, and corolla). The G-type was found on Ulleung-do and Dok-do, and the P-type was observed on the coasts of South Korea, Jeju-do and Ulleung-do. The distinct difference in the morphological types and geographical distribution suggested the existence of two putative lineages with different distribution processes. O. coerulescens, distributed in very limited areas, was only identified as the G-type on Dok-do. Hence, conservation efforts should focus on protecting native habitats to conserve native species and the unique biogeographic significance of this species.

Distribution, Characterization, and Diversity of the Endophytic Fungal Communities on Korean Seacoasts Showing Contrasting Geographic Conditions

  • You, Young-Hyun;Park, Jong Myong;Seo, Yeong Gyo;Lee, Woong;Kang, Myung-Suk;Kim, Jong-Guk
    • Mycobiology
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    • v.45 no.3
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    • pp.150-159
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    • 2017
  • This study analyzed the distribution of endophytic fungi in 3 coastal environments with different climatic, geographical, and geological characteristics: the volcanic islands of Dokdo, the East Sea, and the West Sea of Korea. The isolated fungal endophytes were characterized and analyzed with respect to the characteristics of their host environments. For this purpose, we selected common native coastal halophyte communities from three regions. Molecular identification of the fungal endophytes showed clear differences among the sampling sites and halophyte host species. Isolates were also characterized by growth at specific salinities or pH gradients, with reference to previous geographical, geological, and climate studies. Unlike the East Sea or West Sea isolates, some Dokdo Islands isolates showed endurable traits with growth in high salinity, and many showed growth under extremely alkaline conditions. A smaller proportion of West Sea coast isolates tolerate compared to the East Sea or Dokdo Islands isolates. These results suggest that these unique fungal biota developed through a close interaction between the host halophyte and their environment, even within the same halophyte species. Therefore, this study proposes the application of specific fungal resources for restoring sand dunes and salt-damaged agricultural lands and industrialization of halophytic plants.

Fungal Clusters and Their Uniqueness in Geographically Segregated Wetlands: A Step Forward to Marsh Conservation for a Wealth of Future Fungal Resources

  • Park, Jong Myong;Hong, Ji Won;Lee, Woong;Lee, Byoung-Hee;You, Young-Hyun
    • Mycobiology
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    • v.48 no.5
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    • pp.351-363
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    • 2020
  • Here, we investigated fungal microbiota in the understory root layer of representative well-conserved geographically segregated natural wetlands in the Korean Peninsula. We obtained 574,143 quality fungal sequences in total from soil samples in three wetlands, which were classified into 563 operational taxonomic units (OTU), 5 phyla, 84 genera. Soil texture, total nitrogen, organic carbon, pH, and electrical conductivity of soil were variable between geographical sites. We found significant differences in fungal phyla distribution and ratio, as well as genera variation and richness between the wetlands. Diversity was greater in the Jangdo islands wetland than in the other sites (Chao richness/Shannon/Simpson's for wetland of the Jangdo islands: 283/6.45/0.97 > wetland of the Mt. Gariwang primeval forest: 169/1.17/0.22 > wetland of the Hanbando geology: 145/4.85/0.91), and this variance corresponded to the confirmed number of fungal genera or OTUs (wetlands of Jangdo islands: 42/283> of Mt. Gariwang primeval forest: 32/169> of the Hanbando geology: 25/145). To assess the uniqueness of the understory root layer fungus taxa, we analyzed fungal genera distribution. We found that the percentage of fungal genera common to two or three wetland sites was relatively low at 32.3%, while fungal genera unique to each wetland site was 67.7% of the total number of identified fungal species. The Jangdo island wetland had higher fungal diversity than did the other sites and showed the highest level of uniqueness among fungal genera (Is. Jangdo wetland: 34.5% > wetland of Mt. Gariwang primeval forest: 28.6% > wetland of the Hanbando geology: 16.7%).

Rosa laevigata Michx. (Rosaceae): A Newly Alien Plant in Korea

  • Lee, Woong;Kim, Jung-Hyun;Kim, Jin-Seok
    • Korean Journal of Plant Resources
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    • v.34 no.3
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    • pp.197-202
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    • 2021
  • We found Rosa laevigata Michx., a newly alien plant in Songjinpo-ri, Jangmok-myeon, Geoje-si, Gyeongsang nam-do. Rosa laevigata is native to China, Taiwan, and Vietnam. It is reported as a naturalized species in Japan, South Africa, United States, and the Pacific Islands. Rosa laevigata is distinguished from R. multiflora by the large size of its flower. Its Korean name is 'Wang-jjil-re-na-mu' based on the large flower. Here, we provide precise description, taxonomic key to Korean Rosa species, illustrations and photographs of its habit.

Geographical Isolation and Root-Associated Fungi in the Marine Terrains: A Step Toward Establishing a Strategy for Acquiring Unique Microbial Resources

  • Park, Jong Myong;Hong, Ji Won;Lee, Woong;Lee, Byoung-Hee;You, Young-Hyun
    • Mycobiology
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    • v.49 no.3
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    • pp.235-248
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    • 2021
  • This study aimed to understand whether the geo-ecological segregation of native plant species affects the root-associated fungal community. Rhizoplane (RP) and rhizosphere (RS) fungal microbiota of Sedum takesimense native to three geographically segregated coastal regions (volcanic ocean islands) were analyzed using culture-independent methods: 568,507 quality sequences, 1399 operational taxonomic units, five phyla, and 181 genera were obtained. Across all regions, significant differences in the phyla distribution and ratio were confirmed. The Chao's richness value was greater for RS than for RP, and this variance coincided with the number of genera. In contrast, the dominance of specific genera in the RS (Simpson value) was lower than the RP at all sites. The taxonomic identity of most fungal species (95%) closely interacting with the common host plant was different. Meanwhile, a considerable number of RP only residing fungal genera were thought to have close interdependency on their host halophyte. Among these, Metarhizium was the sole genus common to all sites. These suggest that the relationship between potential symbiotic fungi and their host halophyte species evolved with a regional dependency, in the same halophyte species, and of the same natural habitat (volcanic islands); further, the fungal community differenced in distinct geographical regions. Importantly, geographical segregation should be accounted for in national culture collections, based on taxonomical uniqueness.

Induced Systemic Resistance in plants by Bacillus sp. Isolated from Dok-do Islands (독도 자생식물 번행초로부터 분리한 바실러스 속 식물생장촉진근권 세균에 의한 식물병 저항성 유도)

  • Kim, Seung-Kun;Son, Jin-Soo;Kwon, Duck-Kee;Ghim, Sa-Youl
    • Microbiology and Biotechnology Letters
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    • v.47 no.4
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    • pp.596-602
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    • 2019
  • In September 2017, the rhizospheric soil of Tetragonia tetragonoides (Pall.) Kuntze was further sampled. One hundred and thirty eight species of microorganisms were isolated from the soil. Indole-3-acetic acid (IAA) production, siderophore production, and phosphate degradation were examined in order to confirm bacterial growth from isolated microorganisms. As a result, most strains were able to produce auxins or siderophores and to solubilize phosphate. In addition, 138 isolated strains were treated with tobacco extract and conferred pathogen resistance to host plants upon treatment. As a result, 35 strains that were able to reduce pathophysiology by more the 60% were selected. Among them, 6 strains with high induced systemic resistance (ISR) activity were found. All of these strains belong to the genus Bacillus according to the 16S rDNA sequence analysis. Bacillus aryabhattai KUDC6619 showed outstanding effects with reduced infection in tobacco and pepper plants. Probably, these Bacillus species play a beneficial role by association with T. tetragonoides for its survival in the harsh conditions found on the island of Dokdo.

The Un-Manned Automated Weather(Insolation) Station at the Island "Dok-do" (무인자동 일사측정시스템의 개발 및 독도에서의 성능평가)

  • Lee, Tai-K.;Cho, Suh-H.;Jo, Dok-K.;Auh, P.Chung-Moo
    • Solar Energy
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    • v.11 no.3
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    • pp.3-8
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    • 1991
  • There are fifteen solar radiation measurement stations over the entire country in Korea. However, they are not capable of supplying reliable solar radiation data for remote areas including islands. The un-manned automated insolation measurement station is suitable for these areas due to the electric power shortage and the maintenance problems at these isolated areas. Our main aim in this work is to develop a solar radiation measurement system which collects and stores data by itself utilizing a PV module and a battery as power source for entire system irregardless of the environmental condition. A developed KIER's prototype system along with an independent HWS reference system has been installed at the designated remote island, Dok-do. Global solar radiation has been measured every hour for a 6-month period of time by both systems at this site. A comparison between the measured solar radiation data by each system indicates that there is an excellent agreement showing average 3.0% of an absolute error. It has been observed that the 8-month average global solar radiation was $2,330W/m^2$ day at this island. We came to the conservative conclusion that the developed KIER system is applicable for measuring solar radiation and for supplying reliable fundamental design data for solar energy utilization system at the remote areas.

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