• Journal of Aquaculture
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• v.13 no.2
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• pp.101-105
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• 2000

To select a suitable seed for aquaculture, four strains of Hizikia fusiformis, collected from Haenam, Wando, Yosu, Chungmu and Pusan, were cultured under similar conditions at Wando, southern coast of Korea from December, 1993 to July, 1994. A comparative study on the monthly growth rate of these plants indicated that the maximum growth was attained by Yosu strain in May but the others in June-July. At the harvest time in May, Yosu strain yielded a maximum of 15.8 kg/$m^2$ of culture rope, while that of Pusan a minimum of 1.5 kg/$m^2$.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.525-549
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• 2022

The process of biological invasion is led by the dynamics of a population as a demographic and evolutionary unit. Spatial structure can affect the population dynamics, and it is worth being considered in research on biological invasion which is always accompanied by dispersal. Metapopulation theory is a representative approach to spatially structured populations, which is chiefly applied in the field of ecology and evolutionary biology despite the controversy about its definition. In this study, metapopulation was considered as a spatially structured population that includes at least one subpopulation with significant extinction probability. The early phase of the invasion is suitable to be analyzed in aspects of the metapopulation concept because the introduced population usually has a high extinction probability, and their ecological·genetic traits determining the invasiveness can be affected by the metapopulation structure. Although it is important in the explanation of the prediction of the invasion probability, the metapopulation concept is rarely used in ecological research about biological invasion in Korea. It is expected that applying the metapopulation theory can supply a more detailed investigation of the invasion process at the population level, which is relatively inadequate in Korea. In this study, a framework dividing the invasive metapopulation into long- and middle-distance scales by the relative distance of movement to the natural dispersal range of species is proposed to easily analyze the effect of a metapopulation in real cases. Increased understanding of the mechanisms underlying invasions and improved prediction of future invasion risk are expected with the metapopulation concept and this framework.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.325-334
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• 2023

The invasive red swamp crayfish, Procambarus clarkii, is native to south-central United States and northeastern Mexico. Recently, it has been being spreading in the wild in South Korea. However, its primary sources, introduction routes, establishment, and expansion in South Korea remain unclear. Here, we analyzed genetic diversity and population genetic structures of its domestic natural populations during early invasion, commercial stock from local aquaria (a suspected introduction source), and original United States population using mitochondrial COI gene sequences for 267 individuals and eight microsatellite markers for 158 individuals. Natural and commercial populations of P. clarkii showed reduced genetic diversity (e.g., haplotype diversity and allelic richness). The highest genetic diversity was observed in one original source population based on both genetic markers. Despite a large number of individuals in commercial aquaria, we detected remarkably low genetic diversity and only three haplotypes among 226 individuals, suggesting an inbred population likely originating from a small founder group. Additionally, the low genetic diversity in the natural population indicates a small effective population size during early establishment of P. clarkii in South Korea. Interestingly, genetic differentiation between natural populations and the United States population was lower than that between natural populations and aquarium populations. This suggests that various genetic types from the United States likely have entered different domestic aquariums, leading to distinct natural populations through separate pathways. Results of our study will provide an insight on the level of genetic divergence and population differentiation during the initial stage of invasion of non-indigenous species into new environments.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.72-72
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• 2022

자두나무(Prunus salicina Lindl.)는 세계에서 5번째로 많이 생산되는 과실로, 한국에서 재배하는 자두나무의 기본종은 중국 양쯔강 유역에서 기원했다. 2016년 과수용 자두나무와는 다른 자두나무가 양구에서 발견되었다. 양구군, 인제군, 고성군 일대의 자두나무 개체군의 유전다양성 및 집단 구조 분석을 통해 본 자두나무 개체군의 유전다양성 및 개체군 구조를 확인하고자 했다. 과수용 재배종을 포함한 시료를 채취하여 GBS 분석을 진행했고 주성분 분석과 STRUCTURE 분석을 통해 개체군간 유전적 구조를 확인했다. 재배종의 유전형이 다른 개체군에서도 나타나는 것으로 보아 유의한 유전적 분화가 일어났다고 보기 힘들었다. 하지만 고성군 고진동계곡 등 DMZ에 인접한 집단이 분계도에서 재배종 개체군과 가장 유전적 거리가 있는 것으로 나타났다. 하지만 본 분석으로는 야생집단으로 발견도니 자두나무의 실체와 기원을 단정짓기에는 부족한 것으로 보이며 외군 추가 및 더 많은 시료를 확보하는 등 추가 조사와 분석이 필요하다.

• Korean Journal of Ichthyology
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• v.22 no.4
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• pp.249-255
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• 2010

Ecological characteristics of landlocked and anadromous populations of Hypomesus nipponensis were investigated from December 2008 to April 2009 in the Soyangho (landlocked population) and Hyangho (anadromous population). Morphological differences between the landlocked and anadromous populations were not found. The spawning season was March in the Soyangho and late February in the Hyangho. Individuals of both populations were sexually mature at sizes over 60 mm total length. Gonadosomatic index of the landlocked population (female: 20.5%, male: 3.7%) was higher than in the anadromous population (female: 17.4%, male: 3.3%). Number of eggs in the ovaries was greater in the anadromous Hyangho (7,325) population and fewer in the Soyangho (4,902) population; this corresponded to the greater total length in the former. Condition factor was 0.6 (0.49~0.74) in the Soyangho population and 0.7 (0.47~0.76) in the Hyangho population. Stomach contents of H. nipponensis consisted mainly of zooplankton and aquatic insects, and the size of prey was larger in the Hyangho population than in the Soyangho population.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.419-428
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• 2013

The objectives of this research were to determine ecological characteristics and chemical gradients in two different loach populations-Misgurnus anguillicaudatus ($M_a$) and Koreocobitis rotundicaudata ($K_r$). Eight chemical parameters were compared to test the chemical preferences between the two species. The population of Kr occurred more in better water quality, compared to the $M_a$-population. The $M_a$-population co-occurred more with tolerant species (TS) and omnivores, whereas the $K_r$-population co-occurred more with sensitive species (SS) and insectivores. The differences in the tolerance and trophic composition matched well with the result of stream health assessment, based on the multi-metric model of Index of Biological Integrity (IBI). The IBI value in habitat with the $M_a$-population was "19.6" (range: 8~40) indicating a fair condition, and the IBI values of $K_r$-population was 29.4 (range: 12~40) indicating good condition. Similar results were found in physical habitat health analysis (QHEI). Overall, data analysis showed that the $M_a$-population belong to the tolerant species and $K_r$-population belong to sensitive species in the tolerance classification.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.15-17
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• 2000

진화 연산의 확률적 모델인 베이지안 진화 알고리즘이 개체군의 크기를 1로 제한하고 고정된 차원의 탐색 공간을 갖는 경우, 목표 확률분포에 수렴함이 이전 연구[2]를 통해 증명되었다. 본 논문에서는 개체군의 크기가 2 이상인 경우의 베이지안 진화 알고리즘을 개체군 자체를 하나의 상태로 보는 단일 체인의 베이지안 입자 필터(particle filter)로 변환하여, 입자 필터의 수렴 특성을 이용하여 목표 확률분포에 수렴함을 증명한다.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1996.10a
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• pp.71-75
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• 1996

공정육묘의 생장과 품질은 공정묘개체군(이하 '묘개체군'이라 칭함)내 미기상의 영향을 크게 받는다. 현재까지, 식물생태계의 미기상 변화에 따른 작물생육의 반응 또는 식물생태군의 공기역학적 특성과 관련된 연구$^{(4). (5). (6)}$ 는 노지식물을 대상으로 광범위하게 이루어져 왔으나, 식물종묘공장과 같은 폐쇄계 식물생산 시설에서 묘개체군내의 미기상 특성에 관한 연구는 Kim등$^{(3)}$ 에 의해서 최근들어 시도되었다. (중략)

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.639-650
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• 2022

Abeliophyllum distichum Nakai, a rare plant with distylous characteristics, is native to certain parts of the Korean Peninsula. It is registered on the IUCN Red List of Threatened Species as a globally endangered plant. This study was conducted to establish an appropriate local conservation management plan suitable for future A. distichum populations by comparing and analyzing the flowering characteristics and population size according to distyly based on the results of quantitative surveys in 14 regions, including 8 areas with native populations of A. distichum and 6 natural monument populations. The number of individuals appearing in each population group was surveyed, and the flowering individuals were identified by style as being either pin or thrum flower types as they were being examined and recorded on the site. In total, 13,130 individuals of A. distichum (7,003 flowering and 6,127 non-flowering individuals) were recorded, but the balance of the number of pin- and thrum-flowered individuals in each population was not significant (p<0.05), indicating an imbalanced state. In particular, the Yeongdong (YD) population was very disproportionate compared to other populations, suggesting that its genetic diversity was low and the possibility of inbreeding was high. The average flowering and fruiting rates by management unit were much higher in the natural monument populations (89.2% and 55.3%, respectively) than in the natural habitat populations (39.0% and 8.5%, respectively). It may be due to a difference in reproductive growth resulting from light inflow into the forest caused by the upper crown closure. The area of occupation (AOO) of A. distichum on the Korean Peninsula covered an area of 23,224.5 m². Although the natural monument population was smaller than the natural habitat population, its density was higher, likely as a result of the periodic management of natural monument populations, where the installation of protective facilities in certain areas restricts population spread. Conservation of A. distichum populations requires removing the natural monument populations suspected of anthropogenic and genetic disturbances and expanding the conservation priority population by designating new protected areas. Although the habitats of natural monument populations are managed by the Cultural Heritage Administration and local governments, there are no agencies that are responsible for managing natural habitat populations. Therefore, institutional improvement in the overall management of A. distichum should be prioritized.

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.470-478
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• 2011

Aster altaicus var. uchiyamae is on the list of endangered species in Korea. Using amplified fragment length polymorphism (AFLP) markers, we investigated the genetic diversity within and among four populations (Guram, Dori Island, Samhap, and Danyang) of A. altaicus var. uchiyamae. We also present the collecting strategies that most efficiently capture the genetic diversity of A. altaicus var. uchiyamae. Four AFLP primer combinations produced a total of 936 bands, of which 934 (99.8%) were polymorphic. A high level of genetic diversity (PPB = 45.3%, h = 0.104, I = 0.168, hs = 0.108) was recognized within the populations of A. altaicus var. uchiyamae. A low degree of genetic differentiation ($G_{ST}$ = 0.075, ${\theta}^B$ = 0.079) was detected among the populations. In addition, analysis of molecular variance (AMOVA) showed that genetic variation was greater within populations (91%) than among populations (9%). These results indicate that the high rate of gene flow has played an important role in forming the present populations of A. altaicus var. uchiyamae. According to maximization strategy, 17, 16, and 11 individuals captured all of the genetic variation in Dori Island, Samhap, and Guram population, respectively. The determination the minimum population size of A. altaicus var. uchiyamae in terms of the genetic information is critical and thereby gain reliable decision support for ex situ conservation of the endangered species, A. altaicus var. uchiyamae.