• Title/Summary/Keyword: 개체군

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Stage Structure and Population Persistence of Cypripedium japonicum Thunb., a Rare and Endangered Plants (희귀 및 멸종위기식물인 광릉요강꽃의 개체군 구조 및 지속성)

  • Lee, Dong-hyoung;Kim, So-dam;Kim, Hwi-min;Moon, Ae-Ra;Kim, Sang-Yong;Park, Byung-Bae;Son, Sung-won
    • Korean Journal of Environment and Ecology
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    • v.35 no.5
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    • pp.548-557
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    • 2021
  • Cypripedium japonicum Thunb. is an endemic plant in East Asia, distributed only in Korea, China, and Japan. At the global level, the IUCN Red List evaluates it as "Endangered Species (EN)," and at the national level in Korea, it is evaluated as "Critically Endangered Species (CR)." In this study, we investigated the characteristics of the age structure and the sustainability of the population based on the data obtained by demographic monitoring conducted for seven years in the natural habitat. C. japonicum habitats were observed in 7 regions of Korea (Pochoen, Gapyeong, Hwacheon, Chuncheon, Yeongdong, Muju, Gwangyang), and 4,356 individuals in 15 subpopulations were identified. The population size and structure differed from region to region, and artificial management had a very important effect on the size and structural change of the population. Population viability analysis (PVA) based on changes in the number of individuals of C. japonicum showed a very diverse tendency by region. And the probability of population extinction in the next 100 years was 0.00% for Pocheon, 10.90% for Gwangyang, 24.05% for Chuncheon, and 79.50% for Hwacheon. Since the above monitored study sites were located within the conservation shelters, which restricted access by humans, unauthorized collection of C. japonicum, the biggest threat to the species, was not reflected in the individual viability. So, the risk of extinction in Korea is expected to be significantly higher than that estimated in this study. Therefore, it is necessary to reflect population information in several regions that may represent various threats to determine the extinction risk of the C. japonicum population objectively. In the future, we should expand the demographic monitoring of the C. japonicum population known in Korea.

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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Bayesian Evolutionary Computation by Variational Mixtures of Factor Analyzers for Continuous Function Optimization (연속 변수 함수 최적화를 위한 Variational 혼합 인자 분석 베이지안 진화 연산)

  • Cho Dong-Yeon;Zhang Byoung-Tak
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.07b
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    • pp.697-699
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    • 2005
  • 연속 변수 함수 최적화를 위한 진화 연산에서는 전통적으로 확률 분포를 도입하여 새로운 세대를 생성하는 기법을 사용하고 있다. 최근 들어 이러한 확률 분포를 개체군으로부터 추정하여 보다 효율적으로 최적화를 해결하려는 연구가 진행되고 있다. 본 논문에서는 variational 베이지안 혼합 인자 분석 기법(Bayesian mixtures of factor analyzers)을 사용한 개체군의 분포 추정을 통해 연속 변수 함수의 최적화 문제를 해결하는 방법을 제안한다. 이 기법은 혼합 분포의 개수 추정을 자동화하여 개체군의 다양성을 유지할 수 있기 때문에 지역 최적점으로 일찍 수렴하는 현상을 방지할 수 있으며, 세부 개체군 내의 분포 추정을 통해 탐색을 효율적으로 수행할 수 있다. 잘 알려진 평가 함수들에 대하여 다른 분포 추정 진화 연산과 비교하여 제안하는 방법의 우수성을 검증하였다.

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Population Characteristics of Ichthyofauna and Bluegill, Lepomis macrochirus in 4 Water Dams(Daegok Dam, Sayeon Dam, Daeam Dam, Seonam Dam) in Ulsan Area (울산권 4개 용수댐(대곡댐, 사연댐, 대암댐, 선암댐)의 어류상과 블루길(Lepomis macrochirus)의 개체군 특성)

  • Jang, Chang-Ryeol;Kim, Jin-Hong;Shin, Young-Seob;Lee, Hak-Joon;Kim, Bong-Seok;Kim, Jung-Hwa;Bae, Yang-Seop
    • Korean Journal of Environment and Ecology
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    • v.34 no.5
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    • pp.402-412
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    • 2020
  • This study aims to examine the population characteristics of the fish and the bluegill (Lepomis macrochirus), designated as ecologically disturbing fish, living in four water dams in the Ulsan area and to provide basic data. The survey of fish living in 4 water dams and surrounding tributaries in the Ulsan area from 2016 to 2017 found a total of 1,987 individuals of 28 species of 9 families and identified 6 Korea's endemic species is (21.4% indigenous rate), 4 exotic species, and 2 ecosystem disturbing species. Based on the number of fishes identified, the dominant species was Lepomis macrochirus, and the subdominant species was Hemiculter eigenmanni. The investigation of the age structure of the L. macrochirus found in the 4 water dams in the Ulsan area showed a large population of 1 to 2 old, and the population was growing fast. Moreover, the analysis of the total length-weight relationship and obesity of the L. macrochirus population showed that the regression coefficient b of the total length-weight relationship was greater than 3.0, and the habitat of the L. macrochirus population was in good condition. Obesity had a positive slope, and the growth state was relatively good. The result of this study can be used as useful data to predict the trend of the L. macrochirus fauna inhabiting in 4 water dams in the Ulsan area.

Distribution Characteristics, Population Structure and Dynamics of the Endangered Plant, Viola websteri Hemsl. (멸종위기야생식물인 왕제비꽃(Viola websteri Hemsl.)의 분포특성과 개체군 구조 및 동태)

  • Chae, Hyun-Hee;Kim, Young-Chul;Kwak, Myoung-Hai;Nam, Gi-Heum
    • Korean Journal of Environment and Ecology
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    • v.35 no.1
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    • pp.48-67
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    • 2021
  • Plant species exhibit current characteristics as a result of interactions with environmental conditions. The plants of Viola sp. have selected chasmogamous flowers with vigorous vegetative propagation or development of cleistogamous flowers as an adaptation strategy. Viola websteri is distributed on the Korean peninsula and the eastern part of Jilin Province, China. The center and edge of the distribution are expected to exhibit different population-dynamics. It is necessary to investigate the cause of its current limited distribution even though V. websteri has a mixed-mating strategy. Firstly, We examined the vegetation environment of habitats and evaluated its characteristics. Growth characteristics were examined through plant phenology. We then evaluated the population structure, characteristics of chasmogamous flowers, and productivity of cleistogamous flowers. Moreover, we compared population sizes between 2014 and 2018. Most habitats were located in deciduous broadleaf mixed forests adjacent to valleys. V. websteri produced chasmogamous flowers with self-incompatibility in April-May and cleistogamous flowers in June-September. The cleistogamous flower production is a strategy ensuring seed production under uncertain environmental fluctuations; these were approximately twice as numerous as chasmogamous flowers. The population structure was distinguished into stable and very unstable regions. There were sites where the population experienced a sharp decline in the 2018 compared to that of 2014. This large decline was found in the edge populations. The habitats had different microsites depending on the natural disturbances of drought and the matrix constituting the habitat, thus supporting various plants. Ensuring the production of seeds through cleistogamous flowers, it was determined that rapid seedling re-establishment and population replenishment were possible when the natural disturbance factor was removed. Environmental factors did not equally affect all populations or individuals. Therefore, it was expected that it would be able to persisted in a long time, despite the rapid decrease in the number of individuals in the population regionally. Local extinction and re-establishment are likely to repeat according to environmental change. We propose the additional population investigation based on this works are required. We also suggest a need to assess the long-term population dynamics and the genetic characteristics of chasmogamous flowers and cleistogamous flowers to establish and implement effective conservation strategies.

A phytogeographical study of Sasa borealis populations based on AFLP analysis (AFLP 마커를 이용한 조릿대 개체군의 식물지리학적 연구)

  • Kim, Il Ryong;Yu, Dasom;Choi, Hong-Keun
    • Korean Journal of Plant Taxonomy
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    • v.45 no.1
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    • pp.29-35
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    • 2015
  • Sasa borealis (Hack.) Makino & Shibata is widely distributed in South Korea. With amplified fragment length polymorphism (AFLP) markers, we analyzed the genetic diversity of S. borealis to predict and measure the phytogeographical factors of these populations. Relatively high levels of genetic diversity (PPL = 37.2%, h = 0.143, I = 0.205) and genetic differentiation ($G_{ST}$ = 0.324, ${\theta}^B$ = 0.395) were confirmed in populations of S. borealis. Moreover, an analysis of molecular variance (AMOVA) showed that the rate of differentiation among the populations was 47.7%. The results showed that genetic diversity is inversely proportional to the latitude of the S. borealis populations, indicating that the distribution of S. borealis may have extended from lower to higher latitudes. This method of investigating the correlation between genetic diversity and latitude presents critical information for estimating changes in distributions and plant conservation due to climate change.

Empirical Study on Correlation between Performance and PSI According to Adversarial Attacks for Convolutional Neural Networks (컨벌루션 신경망 모델의 적대적 공격에 따른 성능과 개체군 희소 지표의 상관성에 관한 경험적 연구)

  • Youngseok Lee
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.17 no.2
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    • pp.113-120
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    • 2024
  • The population sparseness index(PSI) is being utilized to describe the functioning of internal layers in artificial neural networks from the perspective of neurons, shedding light on the black-box nature of the network's internal operations. There is research indicating a positive correlation between the PSI and performance in each layer of convolutional neural network models for image classification. In this study, we observed the internal operations of a convolutional neural network when adversarial examples were applied. The results of the experiments revealed a similar pattern of positive correlation for adversarial examples, which were modified to maintain 5% accuracy compared to applying benign data. Thus, while there may be differences in each adversarial attack, the observed PSI for adversarial examples demonstrated consistent positive correlations with benign data across layers.

Feeding Behavior of Etofenprox Resistant Green Peach Aphid (Myzus persicae) against Thiamethoxam and Fenpropathrin (Etofenprox저항성 복숭아혹진딧물(Myzus persicae)의 thiamethoxam과 fenpropathrin에 대한 섭식행동 관찰)

  • Jo, Chang-Wook;Park, Cho-Rong;Yoon, Kyu-Sik;Kang, Min-A;Kwon, Hae-Ri;Seok, Hee-Bong;Kang, Eun-Jin;Seo, Mi-Ja;Yu, Yong-Man;Youn, Young-Nam
    • Korean journal of applied entomology
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    • v.48 no.4
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    • pp.493-501
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    • 2009
  • To investigate resistance of Myzus persicae, which is resistant to etofenprox belonging to pyrethriods, to other insecticides, fenpropathrin and thiamethoxam, mortality and $LC_{50}$ values for these two insecticides against the etofenprox-resistant and -susceptible populations were obtained and EPG analysis for feeding behaviors of thiamethoxam or fenpropathrin treated and non-treated M. persicae was conducted. For fenpropathrin, mortality after 48 h treatment was 28 and 29%, respectively for the resistant and susceptible population. The $LC_{50}$ value was 193.15 and 93.46 ppm, respectively. For thiamethoxam, mortality after 48 h treatment was 87 and 57%, respectively for the resistant and susceptible population. The $LC_{50}$ value was 3.17 and 30.34 ppm, respectively. There was no significant difference in feeding behavior between fenprorpathrin treated and non-treated M. persicae. They showed a continuous feeding pattern. However, contact signal frequency increased in the thiamethoxam treated M. persicae 1 hour after treatment and significant difference was shown.

Population Dynamics of Korean Chub(Zacco koreanus, Cyprinidae) in the Upstream and Downstream of Lake Hoengseong (횡성호 상.하류에 분포하는 참갈겨니(Zacco koreanus, Cyprinidae)의 개체군 동태)

  • Choi, Jae-Seok;Park, Seung-Chul;Jang, Young-Su;Lee, Kwang-Yeol;Choi, Jun-Kil
    • Korean Journal of Environment and Ecology
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    • v.20 no.4
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    • pp.391-399
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    • 2006
  • The population dynamics of Zacco koreanus in the upstream and downstream of Hoengseong Lake, Korea were investigated from April to October 2005. As the result of a comparison of variations regarding the time of I koreanus populations, it was confirmed that downstream was a place to remain compared to upstream Also the b value, assessed by Length-weight relationship in upstream and downstream, were $3.21{\sim}3.35,\;and\;2.94{\sim}3.37$, respectively indicating the fish in downstream had better than upstream. Additionaly condition factor(K) of each population in upstream and downstream were $0.0292{\sim}0.0693\;and\;-0.0165{\sim}0.0499$, respectively, K value in upstream lower than downstream. On the other hand, the maximum-growth value$(L_{\infty})$ calculated by von Bertalanffy's growth model in upstream and downstream were 279.7mm and 303.9mm, respectively, indicating that the potential-growth ability of population in downstream was higher than population in upstream. Therefore, Z. koreanus population in upstream became worse based on matters of age structure, Length-weight relationship, and von Bertalanffy's growth model. These results are considered to show the change of the physical environment by the constructing of Hoengseong Dam.

Comparison of Life Table and Feeding Behavior of Resistance and Susceptible Population of the Green Peach Aphid, Myzus persicae (Hemiptera: Aphididae) against Etofenprox (Etofenprox에 대한 복숭아혹진딧물(Myzus persicae)의 저항성과 감수성 개체군의 생명표와 섭식행동 비교)

  • Jo, Chang-Wook;Park, Cho-Rong;Yoon, Kyu-Sik;Kang, Min-A;Kwon, Hae-Ri;Kang, Eun-Jin;Seo, Mi-Ja;Yu, Yong-Man;Youn, Young-Nam
    • Korean journal of applied entomology
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    • v.48 no.3
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    • pp.301-310
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    • 2009
  • For the comparing of mortality of the resistance and susceptible population of Myzus persicae, etofenprox was treated in the recommended concentration of 200ppm. Mortalities of resistance population were 16.7 and 36.7%, and susceptible population were 86.7 and 86.7% after 24 and 48 hours treatment, respectively. For the detect of cross resistance to other pyrethroids, 6 pyrethroids were examined. Mortalities of susceptible and resistance populations were 90 and 31% to deltamethrin, 92 and 23% to lambda cyhalothrin, 81 and 14% to cypermethrin, 70 and 20% to $\alpha$-cypermethrin, 29 and 28% to fenpropathrin, 84 and 29% to fenvalerate, respectively. It was showed that resistance populations were generally resistive to other pyrethroids. On the other hands, for recognized ecological characteristic of M. persicae susceptible and resistance populations life table was tested on the pepper leaves in the petri dish and on the plant in the pot. This results were showed that intrinsic rate of increase ($r_m$), net reproduction number ($R_0$) and generation time in day ($T_c$) were significantly different between two population in both tested. However, life span and reproduction period were slightly different between them. Otherwise, feeding behaviors were tested using EPG technique with non- and treated etofenprox. First potential drop time of susceptible and resistance population was 73.5 and 257.9 sec with non-treated and 93.3 and 1076.2 sec after treated, respectively. Electrical probing signals were 8.2 and 48.8 times with susceptible and resistance individuals after treated etofenprox, respectively. It was supposed that the resistance is more probings than susceptible population. After treated, total feeding time have more 6,728.9 sec on resistance than 965.5 sec on susceptible population. So, total non penetration time of susceptible population was 3,000 sec longer than resistance population.