• Title/Summary/Keyword: INTRODUCED DISTURBING PLANTS

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A Study on the Flora and Its Naturalized Plants of Mt. Teomo·Hyeolgu(Incheon, Ganghwa-gun) in the Western Part of DMZ, Korea (서부 DMZ일원 퇴모·혈구산(인천광역시 강화군)의 식물상 및 귀화식물에 관한 연구)

  • Lee, Jong-Won;Yun, Ho-Geun;Kim, Dong-Hak;Song, Jin-Hun;Kim, Sang-Jun;Gil, Hee-Young
    • Korean Journal of Environment and Ecology
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    • v.36 no.1
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    • pp.1-29
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    • 2022
  • This study surveyed the Mt. Teomo·Hyeolgu and surrounding areas in Ganghwa Island, located in Ganghwa-gun, Incheon, to identify vascular flora and alien plants to be used as basic data for systematic management of the remarkable plants and biodiversity conservation. The survey was carried out 13 times from March 2019 to October 2020. The identified vascular flora of Mt.Teomo·Hyeolgu was 101 families, 321 genera, 517 species, 13 subspecies, 38 varieties, 5 forms, and 573 taxa. They accounted for about 12.35% of a total of 4,641 taxa of vascular plants in Korea. The identified Northern lineage plants, endemic plants, and rare plants on the Korean Peninsula as designated by IUCN were 68 taxa, 10 taxa, and 9 taxa, respectively. 69 taxa were classified as floristic target species. Three taxa, including Maui sedge [Carex thunbergii var. appendiculata (Trautv. & C.A.Mey.) Ohwi] were identified s Class IV and 14 taxa, including Violet Stanavoi clematis (Clematis fusca var. violacea Maxim.) were identified as Class III. The naturalized plants that appeared in the study site were 63 taxa, including daisy fleabane [Erigeron annuus(L.) Pers.], common ragweed [Ambrosia artemisiifoliaL.] and Canadian fleabane [Conyza canadensis(L.) Cronquist]. The above three species were found to have spread throughout Ganghwa Island and surrounding areas such as Seokmo Island, Gyodong Island, and Gimpo city. As introduced disturbing plants like prickly lettuce [Lactuca scariola L.], bur cucumber [Sicyos angulatus L.] and field dock [Rumex acetosella L.] have been newly reported in the Mt. Teomo·Hyeolgu area, mid- to long-term conservation measures should be established for native plants, such as remarkable plants, and also management measures like physical removal should be prepared at an early stage.

The Flora of Vascular Plants in Mt. Chijae(Gamagol) and Its Adjacent Areas (in Damyang-gun, Jeonnam-do, Korea) (담양군 치재산(가마골) 일원 관속식물상)

  • Soon-Ho Shin;Kyoung-Pae Yun;Sang-Mi Kim;HyunSuk Kim
    • Korean Journal of Environment and Ecology
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    • v.38 no.1
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    • pp.22-47
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    • 2024
  • This study aims to reveal the distribution of native plants, rare plants, and specialty plants and provides basic data for efficient ecosystem management through a survey of the flora in Mt. Chijae (Gamagol) and its adjacent areas in Damyang-gun, Jeonnam-do, while also identifying useful plants in the eco-city Damyang-gun for distinctive garden plants. A total of 21 field surveys were conducted from March 2022 to June 2023 to collect and identify 492 taxa consisting of 101 families, 304 genera, 444 species, 10 subspecies, 35 varieties, and 3 formas. The analysis of the prepared sample list showed 14 taxa designated as specialty plants, 9 taxa designated as rare plants by the Korea Forest Service, 7 taxa designated as the national red (i.e., endangered) plants by the Ministry of Environment, and 68 taxa with phylogenetic specific species, of which 45 taxa for Grade I, 5 taxa for Grade II, 16 taxa for Grade III, and 2 taxa for Grade IV were confirmed. The list included 155 taxa of biological resources subject to export approval by the Ministry of Environment and 38 taxa of alien plants of which 7.7 percent were naturalized, and the urbanization index was 6.1 percent. Four taxa were ecosystem-disturbing invasive alien plants designated by the Ministry of Environment introduced artificially or naturally from abroad. This study is expected to contribute to creating unique and attractive landscapes in Damyang if the specific plants found in Mt. Chijae are grown and planted in city gardens.

Analysis of signal cable noise currents in nuclear reactors under high neutron flux irradiation

  • Xiong Wu;Li Cai;Xiangju Zhang;Tingyu Wu;Jieqiong Jiang
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4628-4636
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    • 2023
  • Cables are indispensable in nuclear power plants for transmitting data measured by various types of detectors, such as self-powered neutron detectors (SPNDs). These cables will generate disturbing signals that must be accurately distinguished and eliminated. Given that the cable current is not very significant, previous research has focused on SPND, with little attention paid to cable evaluation and validation. This paper specifically focuses on the quantitative analysis of cables and proposes a theoretical model to predict cable noise. In this model, the reaction characteristics between irradiated neutrons and cables were discussed thoroughly. Based on the Monte Carlo method, a comprehensive simulation approach of neutron sensitivity was introduced and long-term irradiation experiments in a heavy water reactor (HWR) were designed to verify this model. The theoretical results of this method agree quite well with the experimental measurements, proving that the model is reliable and exhibits excellent accuracy. The experimental data also show that the cable current accounts for approximately 0.2% of the total current at the initial moment, but as the detector gradually depletes, it will contribute more than 2%, making it a non-negligible proportion of the total signal current.

A Study on the Flora and its Introduced Disturbing Plants in Damyang Area of Mudeungsan National Park, Korea (무등산국립공원 담양 지구의 식물상과 생태계교란 식물에 관한 연구)

  • Lee, Jong-Won;Lee, Suhong;Kang, Shin-Ho
    • Korean Journal of Plant Resources
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    • v.34 no.1
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    • pp.103-113
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    • 2021
  • This study was investigated to find out the distribution of flora and remarkable plants and factors and management measures for influx of wild disturbed plants in the Damyang area of Mudeungsan National Park. The field survey was carried out 8 times from May 2019 to October 2020. First of all, in the Damyang area of Mudeungsan National Park, a total of 603 taxa in 107 families, 349 genera, 531 species, 57 varieties, 5 subspecies and 10 forms. This result was found to be about 12.33% of the total 4,881 taxa of vascular plants in Korea. In addition, Rare plants were classified as 15 taxa. Floristic special and Korean endemic plants were identified as 85 taxa and 13 taxa, respectively. Lastly, the naturalized plants that appeared in the Damyang area of Mudeungsan National Park were observed in 45 taxa with 45 species of 16 families and 36 genera. Moreover the naturalization rate was 7.46% and the urbanization index was calculated to be 14.01%. The wild disturbed plants were found in a total of 4 taxa. Especially, a sheep sorrel(Rumex acetosella) was focused on managing for physica and biological control at Sinseondae Eoksaepyungjeon.

The Fish Community Structure in the Middle of Nakdong River (낙동강 중류(구미 지역)의 어류군집구조)

  • Seo, Jun-Won;Keum, Ji-Don;Yang, Hong-Jun;Kang, Yeong-Hoon
    • Korean Journal of Ecology and Environment
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    • v.37 no.2 s.107
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    • pp.227-235
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    • 2004
  • Fish fauna and community structure were surveyed in the Nakdong River, Gumi City, Kyeongpook province from April 2001 to July 2002. During the surveyed Period, 39 species, 32 genera belonging to 10 families were collected. Cyprinid fish occupied 64.1% (25 species) and cobitid fish had 7.7% (3 species). Fourteen species(35.9%) of observed species were known as endemic species. The exotic fish was Micropterus salmoides (2.5%) . The dominant species were Zacco platypus (relative abundance: 36.7%) and Opsariichthys uncirorstris amurensis (22.7%). Carassius aurafus and Microphysogobio rapidus were numerous (4.0${\sim}$4.3%). The rare species comprising less than 0.15% were Acheilognathus koreensis, Aphyocypris chinensis, Iksookimia longicorpus, Coreoleuciscus splendidus, Rhinogobius giurinus, Sarcocheilichthys variagatus wakiyae, Silurus asotus astus, and Channa argus. It was found that the population density of carnivorous Opsariichthys uncirostris amurensis increased drastically in the mid-reach of the Nakdong river since it had been introduced from the other native rivers in the middle 1990s. Gobiobotia nakdongensis inhabit riffle (water velocity : 0.43${\sim}$0.67 m $s^{-1}$) of which the river bed is mainly sand. This species is considered to be in need of conservation. As the result of analyzing fish community in the surveyed area, the species diversity, evenness and dominant indices were 1.008, 0.663 and 0.196 respectively. The findings showed that the tributary, which the waterside plants were abundant and had various habitats, had a higher species diversity (1.112) than the main river (0.787). Sand mining had been disturbing the river ecosystem of the study stations 3, 11, 13 & 14, and these stations showed a quite low species diversity (0.421 ${\sim}$0.574).