• Title/Summary/Keyword: EOO (Extent of occurrence)

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Assessing Red List categories to a Korean endangered species based on IUCN criteria - Hanabusaya asiatica (Nakai) Nakai- (멸종위기식물의 IUCN 적색목록 보전지위 평가 -금강초롱꽃에 대하여-)

  • Park, Soo-Kyung;Kim, Hui;Chang, Chin-Sung
    • Korean Journal of Plant Taxonomy
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    • v.43 no.2
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    • pp.128-138
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    • 2013
  • The conservation status of an endemic perennial herb, Hanabusaya asiatica (Nakai) Nakai (Campanulaceae) was determined by applying the IUCN risk assessment criteria from our field study and available specimen data. Also, the GIS technology was used to develop a species distribution map to calculate the extent of occurrence (EOO) and area of occupancy (AOO) for the taxon. After two years of continuous field studies, 269 mature individuals were found in four localities in 2011, while 216 mature individuals were confirmed in three localities in 2012. Based on the following data, such as EOO (2,742 $km^2$), AOO (76 $km^2$) and estimated population size of mature individuals, the taxon, which is known as 20 localities in Korean peninsula, is evaluated as the category of Endangered (EN). A major difficulty in application of IUCN criteria to Korean rare plants were the lack of essential biological information and understanding the correct knowledge of the IUCN criteria in previous Korean studies. Sound conclusions regarding the conservation status of individual species require more intensive population studies, observations, and applying IUCN assessment procedures correctly.

Population Characteristics of Echinosophora koreensis (Nakai) Nakai, a Endemic Plants in Korea (한반도 특산식물 개느삼의 개체군 특성)

  • Kim, Sodam;Moon, Ae-Ra;An, Jong-Bin;Jung, Ji-Young;Park, Wan-Geun;Son, Sungwon
    • Korean Journal of Environment and Ecology
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    • v.34 no.1
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    • pp.18-26
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    • 2020
  • Echinosophora koreensis (Nakai) Nakai an endemic plant with limited distribution in some parts of the Korean Peninsula, is designated as "Endangered" species on the IUCN Red List. The species is under the threat of deterioration in nature due to various environmental changes causing loss of natural habitats. We investigated the distribution pattern and population structure of E. koreensis to serve as a basic reference for identifying the dynamics and persistence of natural populations of this species in the future. To determine the characteristics of the E. koreensis population, we laid two to three large plots sized 20m×30m on the ridgeline as the reference in Yanggu, Chuncheon, and Hongcheon and laid four to seven small quadrats sized 1m×1m on the transect. A total of 530 plots were laid, 10 each at 2m interval, to measure the number of the stems, the number of fruiting, height, and other factors. The collected distribution information was compared with the existing IUCN assessed categories by applying IUCN Red List ver 3.1 Criteria B. The average population density of the three surveyed areas was 3.47 stem/㎡; the density of each area was 3.95 stems/㎡ in Yanggu, 3.37 stems/㎡ in Chuncheon, and 2.87 stems/㎡ in Hongcheon. The number of fruiting per stem was 0.0038, indicating only 7 fruits out of 1,837 stems and that vegetative reproduction is likely to be more dominant than sexual reproduction. The distribution tendency of population density in the small plots in three surveyed areas showed that the density of E. koreensis tended to decrease toward the center of the forest with low crown openness and around the mountain ridge with high crown openness. It indicated that the quantity of light could be a very important factor for the growth of individuals of this species. The analysis of the heights of individuals present in the surveyed plots showed a range of 2.3 ~ 68.5cm and an average of 20.1cm. An analysis on the stage-structure of the E. koreensis population based on the sieve height found that the appearance frequency decreased with increasing height above 15 ~ 20cm and that the percentage of individuals lower than 10cm, which were presumed to be seedlings, was severely low, indicating a necessity of study on the population sustainability based on the monitored data. The occupied area calculated with the collected species distribution information was 200㎢, indicating the EN category according to the IUCN Red List Reference B.

Distribution Aspect and Extinction Threat Evaluation of the Endangered Miho Spined Loach, Cobitis choii (Pisces: Cobitidae) (멸종위기어류 미호종개 Cobitis choii(Pisces: Cobitidae)의 분포양상과 멸종위협 평가)

  • Myeong-Hun Ko;Mee-Sook Han
    • Korean Journal of Ichthyology
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    • v.36 no.1
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    • pp.48-57
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    • 2024
  • Distribution status and extinction threat evaluation of an endangered species, Cobitis choii, were investigated from 2015 to 2019. In 2015 and 2018, we investigated past appearance sites of C. choii. In 2015, 163 individuals from nine sites were collected by surveying 19 stations. In 2018, 19 individuals from five sites were collected by surveying 22 sites. In 2019, 156 individuals from 12 sites were collected as a result of a survey of 79 sites of past appearance and potential appearance of C. choii. Appearance regions were Mihocheon (Baekgokcheon (2 sites), Chopyeongcheon (1 sites)), Gapcheon (3 sites), Yugucheon (2 sites), Jicheon (4 sites), and Geumgang mainstream (2 sites). Among these appearing regions, Baekgokcheon, Yugucheon, and Mihocheon mainstreams showed a sharp decline in population. Baekgokcheon was estimated to have a habitat change due to a project to raise the bank of Baekgok Reservoir. Yugucheon was estimated to have a habitat disturbance due to flood-induced collapse and reconstruction of weir. Mihocheon mainstream was estimated to have water pollution and habitat disturbance. On the other hand, Chopyeongcheon and Geumgang mainstream were newly habitat identified and Gapcheon was noted to show an increase in the number of individuals. After performing extinction threat evaluation, C. choii was evaluated as Endangered (EN A2ac) due to its rapid population decline (more than 50%) in its habitats of Baekgokcheon, Yugucheon, and Mihocheon based on criteria A, while it was evaluated as Vulnerable (VU B1ab (iii,v) +B2ab +B2ab (iii,v)) due to its narrow extent of occurrence (EOO, 1,735 km2) and area of occupancy (AOO, 36 km2) in 6 locations with a continuous population decline based on criteria B. Therefore, the final threat of extinction grade was evaluated as Endangered (EN A2ac). In Baekgokcheon, Yugucheon, and Mihocheon mainstream where the population has declined rapidly recently, conservation measures are urgently required to increase its population.