• Title/Summary/Keyword: Population Ecology

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Deep-sea Hydrothermal Vents: Ecology and Evolution

  • Won, Yong-Jin
    • Journal of Ecology and Environment
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    • v.29 no.2
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    • pp.175-183
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    • 2006
  • The discovery of deep-sea hydrothermal vents and their ecosystems is a monumental landmark in the history of Ocean Sciences. Deep-sea hydrothermal vents are scattered along the global mid-ocean ridges and back-arc basins. Under sea volcanic phenomena related to underlying magma activities along mid-ocean ridges generate extreme habitats for highly specialized communities of animals. Multidisciplinary research efforts during past three decades since the first discovery of hydrothermal vents along the Galapagos Rift in 1977 revealed fundamental components of physiology, ecology, and evolution of specialized vent communities of micro and macro fauna. Heterogeneous regional geological settings and tectonic plate history have been considered as important geophysical and evolutionary factors for current patterns of taxonomic composition and distribution of vent faunas among venting sites in the World Ocean basins. It was found that these communities are based on primary production of chemosynthetic bacteria which directly utilize reduced compounds, mostly $H_2S$ and $CH_4$, mixed in vent fluids. Symbioses between these bacteria and their hosts, vent invertebrates, are foundation of the vent ecosystem. Gene flow and population genetic studies in parallel with larval biology began to unveil hidden dispersal barrier under deep sea as well as various dispersal characteristics cross taxa. Comparative molecular phylogenetics of vent animals revealed that vent faunas are closely related to those of cold-water seeps in general. In perspective additional interesting discoveries are anticipated particularly with further refined and expanded studies aided by new instrumental technologies.

Diet analysis of Clithon retropictum in south coast of Korea using metabarcoding

  • SoonWon Hwang;Kwangjin Cho;Donguk Han;Yonghae Back;Eunjeong Lee;Sangkyu Park
    • Journal of Ecology and Environment
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    • v.48 no.2
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    • pp.144-151
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    • 2024
  • Background: This study focused on the diet of Clithon retropictum, level II endangered species in Korea. Since the development of brackish water zones has led to a decline in the population of this species, to obtain information on the ecology of C. retropictum required for its conservation and restoration. To investigate the actual preys of C. retropictum in south coast of Korea, we conducted high-throughput sequencing and metabarcoding techniques to extract DNA from gut contents and periphyton in their habitats. Results: Total 118 taxonomic groups were detected from periphyton samples. 116 were Chromista and Cyanobacteria dominated in the most samples. In gut contents samples, 98 taxonomic groups were detected. Similar to the results of periphyton, 96 were Chromista and Cyanobacteria dominated in the most samples. In the principal component analysis based on the presence/absence of taxonomic groups, gut content composition showed more clustered patterns corresponding to their habitats. Bryophyta was the most crucial taxonomic group explaining the difference between periphyton and gut contents compositions of C. retropictum. Conclusions: Our finding suggests that C. retropictum may not randomly consume epilithic algae but instead, likely to supplement their diet with Bryophyta.

Planning Non-Invasive Conservation Genetic Experiments Based on Factors Affecting DNA Amplification Using Fecal Samples of Korean Long-Tailed Goral (Naemorhedus caudatus)

  • Baek-Jun Kim
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.5 no.3
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    • pp.71-75
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    • 2024
  • In this review, we compared the success rates of DNA amplification and introduced the efficient non-invasive sampling of fecal samples collected from captive and wild Korean long-tailed gorals (Naemorhedus caudatus) by referring to previous non-invasive studies, including three important references (Kim et al., 2008; Kim, 2021; Kim, 2022). A large difference in PCR success rates in the captive and wild populations was observed for mitochondrial (100 and 70.0%), sex-linked (44.4 and 20.8%), and microsatellite markers (73.9 and 34.8%, respectively). Out of the three types of genetic markers, the mitochondrial maker showed the highest success rate, followed by microsatellite and sex-linked markers. In addition, we estimated two factors that affected the PCR success, including the length of the amplified fragments (long, medium, and short) and the type of primer (universal and specific) in fecal samples from a captive population. The length of the PCR fragment was inversely proportional to the PCR success (5.3, 44.4, and 55.6% for long, medium, and short fragments, respectively), and the specific primer set (100%) was more efficient than the universal primer set (60.0%). This review is fundamental but would be greatly helpful for new non-invasive conservation genetic studies, particularly those that use fecal samples from captive and wild populations of rare endangered species. We recommend beginning conservation genetic experiments using mitochondrial markers and then nuclear markers, such as microsatellite and sex-linked markers, to save time, costs, and labor.

A Study on the Trend of the School Violence in Elementary schools (초등학생의 학교폭력 실태와 경향에 대한 연구)

  • Kim, Sun-Ae
    • Korean Journal of Human Ecology
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    • v.12 no.3
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    • pp.321-336
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    • 2003
  • This study aims at more exactly identifying current status and trend of the school violence in elementary schools. Many previous studies have addressed the issue with their own views and methodologies, and mostly ended up as one-time works without subsequent observation over years. From such respective studies, we could hardly figure out an integral and precise shape on the school violence in terms of fact and tendency. To my knowledge, this is the first time-lag design on the school violence which is conducted nation wide, where the same concepts and measures were applied to the population. The research conclusions are follows: (1) both offenders and victims of the school violence tend to increase, (2) compared 10 girls, boys have more experience of the school violence, and (3) both offenders and victims could be recruited from the same group.

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A Comparative Study of the Welfare Policy for the Aged in Rural and Urban in China (중국 도시와 농촌의 노인복지정책에 관한 비교 연구)

  • Gao, Chun-Lan;Kim, Seon-Hee
    • Korean Journal of Human Ecology
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    • v.10 no.2
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    • pp.37-42
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    • 2007
  • The scale and the extent of a aging of population of a rural are more serious than those of a urban in China. However, the welfare policy and the service for the aged in the rural are inferior. China established the different systems of social welfare policy for the city and the rural and has administered it since the china was established. Owing to an open-door policy(opening of a reform) the gap between the two got more deeply distinguished. Accordingly. the striking difference is shown in a living environment and a quality of life of the cities and the rural. I made clear the difference of services for the aged in the rural and the urban examining daily lives, medical industry, recreation systems and so on and analyzing their sources. In addition, I proposed the ways to establish synthetic social welfare policy of the urban and the rural.

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Dynamic Patterns of Abies korean Population in Chirisan National Park -Central of East Area in Chirisan National Park- (지리산국립고원 구상나무개체군 동태-지리산국립공원 동부지역을 중심으로-)

  • 지용기
    • Korean Journal of Environment and Ecology
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    • v.13 no.4
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    • pp.330-339
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    • 2000
  • 지리산 국립공원의 동부지역을 대상으로 구상나무개체군 동태를 파악하기 위하여 1999년 7월에 49개의 조사구(20m$\times$15m)를 설치하여 식생구조를 조사하였다. 조사대상지의 구상나무는 북사면에서 해발 900m 이상 남사면에서 해발 1,000m 이상에서 분포하였다 구상나무의 상대우점치는 북사면의 경우 해발 1,300-1,500m 사이에서 높게나타났으며 남사면의 경우 해발 1,400-1,600m 사이에서 높게 나타났다. 조사구별 구상나무의 상대우점치는 북사면에서 높게 나타났으나 흉고직경 2-17m 미만의 개체수 경우 북사며에서보다 남사면의 조사구에서 많이 나타났고 대경목은북사면에서 많이 나타났다.

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Ecological Characteristics of Daphniphyllum macrop-odum Population in the Naejangsan National Park (내장산국립공원 굴거리나무 개체군의 생태적 특성에 관한 연구)

  • 임윤희;오구균
    • Korean Journal of Environment and Ecology
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    • v.13 no.1
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    • pp.17-33
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    • 1999
  • 내장산국립공원에 자생하고 있는 굴거리나무 개체군의 분포와 식생구조를 분석하였다. 굴거리나무 개체군은 내장사지구의 금선계곡과 원적계곡, 백양사지구의 운문암 주변에서 분포하고 있으며, 그 면적은 각각 1.8km2, 0.6km2 이었다. 굴거리나무 개체군의 밀도는 금선계곡 전망대 주변이 가장 높았고, 금선계곡과 운문암 주변에서 비교적 높았다. 굴거리나무는 경사가 급한 전석지대에서 생육하고 있으며, 대팻집나무, 산딸나무, 작살나무와 생태적 적소가 유사한 것으로 생각된다. 식생구조분석 결과 내장산국립공원 산림의 아교목층과 관목층에서 굴거리나무의 우점도가 증가할 것으로 예상된다.

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The Characteristic of Fish Fauna and Brachimystax lenok tsinlingensis Individuals in the Bonghwa-gun, Korea (봉화군의 어류상과 열목어(Brachimystax lenok tsinlingensis) 개체군의 특성)

  • Byeon, Hwa-Kun
    • Korean Journal of Environment and Ecology
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    • v.25 no.6
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    • pp.878-886
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    • 2011
  • The fish fauna and characteristic of population of Brachymystax lenok tsinlingensis at the 7 stations in the Bonghwa-gun were investigated from June 2010 to May 2011. The collected species during the survey period were 15 species belong to 7 families. Protected species by the legal were B. lenok tsinlingensis, Koreocobitis naktongensis, and Cottus koreanus. Korean endemic species were Microphy sogobio yaluensis, Coreoleuciscus splendidus, Zacco koreanus, Cobitis hankugensis, K. naktongensis, Iksookimia longicorpa, Niwaella multifasciata, Liobagrus mediadiposalis, C. koreanus, and Coreoperca herzi, which showed a ration of 66.7% in collected species. Dominant species were Z. koreanus(St. 1), B. lenok tsinlingensis(St. 3, 4, 5), and Rhynchocypris oxycephalus(St. 2, 6, 7). Length-weight relation in the population of B. lenok tsinlingensis was BW = $0.000008TL^{3.02}$, and condition factor in the population was average 0.84. Frequency analysis of total length indicated that the group 80~180 mm in total length is represented by one-year-old individuals, the group 200~300 mm by two-year-old individuals, and the group over 300 mm by three-year-old individuals. The density of population was presumed average 17 individuals per 100$m^2$ and total 4,760 individuals in the reservation for B. lenok tsinlingensis.

Genetic Diversity of Salicornia herbacea according to Habitat Area by ISSR Markers (ISSR 마커를 이용한 서식 면적에 따른 퉁퉁마디의 유전적 다양성)

  • Kim, Suk-Kyu;Cho, Yoon Sik;Hur, Young Baek;Song, Jae Hee;Jeong, Hee Do;Chung, Sang Ok
    • Korean Journal of Environment and Ecology
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    • v.31 no.6
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    • pp.492-499
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    • 2017
  • This study analyzed 96 individuals in 6 populations using ISSR marker to investigate the genetic diversity of Salicornia herbacea populations. The total of 49 PCR amplification bands was observed in 6 ISSR primers, and 30 of them had genetic polymorphisms. The Shannon's information index (I) and gene diversity index (h), which indicate the genetic diversity of the Salicornia herbacea populations, were 0.382 and 0.249, respectively. The genetic diversity according to the population size was lowest with 0.092 (I) and 0.058 (h) in $0.1m{\times}0.1m$ and highest with 0.338 (I) and 0.227 (h) in $25m{\times}25m$, which was suitable for the furtherance of the high population with high genetic diversity. The UPGMA dendrogram based on Nei's genetic distance did not show a significant correlation with the distance between the Salicornia herbacea population. The results indicate that the Salicornia herbacea habiting in the restricted environment should have an area over a certain size to ensure the formation of a population with genetic diversity.

Study on Minimum Viable Population of Seed Bank in Pine Forest (소나무림 매토종자 최소생존가능개체군에 관한 연구)

  • Yi, Myung-Hoon
    • Korean Journal of Environment and Ecology
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    • v.32 no.5
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    • pp.497-506
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    • 2018
  • The purpose of this study was to investigate the proper minimum viable population of a seed bank for the ecological restoration of pine forest using a seed bank. It examined the germinated soil seed bank from August 2010 to November 2011. The results of the correlation analysis showed that the area and the number of herbaceous species were the highest at 0.686. The results of the regression analysis of four variables including the number of woody species, the number of woody individuals, the number of herbaceous species, and the number of herbaceous individuals using the theory of island biogeography to the minimum viable population in studied plots showed that all four variables were significant with area at the level of 0.05, and R square was 0.583. One function was selected between the number of species and the number of individuals from the canonical correlation analysis, and the function square was 0.824. Both canonical function and squared canonical correlation showed significant at the level of 0.01. The result of study recommended the area size of the minimum viable population in pine forest applied by seed bank to be larger than $64m^2$, the number of species to be over 21, and the number of population to be over 120. It also found that the number of herbaceous species determined the cluster size of the seed bank. Therefore, it is necessary to consider herbaceous species that appear in the seed bank.