• Title/Summary/Keyword: multidimensional scaling

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Species Composition and Species Diversity of Moths (Lepidoptera) on Quercus mongolica forests sand Pinus densiflora forests, in Korean National Long-term Ecological Research Sites (Mt. Nam, Mt. Jiri, Mt. Wolak) (국가 장기 생태 연구지(남산, 지리산, 월악산)의 신갈나무림과 소나무림에서 포획된 나방류의 종조성 및 종다양도)

  • Yi, Hoon-Bok;Kim, Hyun-Jung
    • Korean journal of applied entomology
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    • v.49 no.2
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    • pp.105-113
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    • 2010
  • Moths were collected using a 22W UV black light trap in June through September in 2005 and May, June, August and September in 2006. The study sites were Namsan (Mt. Nam), Jirisan (Mt. Jiri), Woraksan (Mt. Worak) which are part of the Korean National Long Term Ecological Research (KNLTER). There were two common forest communities, Quercus mongolica and Pinus densiflora. The purpose of this study was to compare species diversity of the major plant feeding Lepidoptera in the two forest types at the regional KNLTER sites. We collected a total of 435 species from the KLTER sites in 2005 and 2006. Abundance of moths was highest at Woraksan (Mt. Worak) followed by Jirisan (Mt. Jiri). The Namsan (Mt. Nam) site had the lowest, with five families (Arctiidae, Geometridae, Noctuidae, Notodontidae, and Pyralidae). Analysis of variance (ANOVA) showed statistically significant differences at sampling date in species abundance as a response variable and at site in species richness as another response variable. Although we expected a distinct cluster with the forest type at each study site, one of ordination analyses, nonmetric multidimensional scaling (NMS), showed distinct clusters with the moth assemblages at each site only but NMS did not show any distinct cluster with the different forest types at each site as we expected.

Meiofauna Community from Sandy Sediments Near Taean in the Yellow Sea, Korea (서해 태안 사질 퇴적물에 서식하는 중형저서동물 군집구조 연구)

  • Back, Jin-Wook;Kim, Ki-Choon;Lee, Seung-Han;Lee, Kang-Hyun;Lee, Dong-Ju;Chae, Jin-Ho;Lee, Won-Choel
    • Ocean and Polar Research
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    • v.31 no.2
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    • pp.199-212
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    • 2009
  • The community structure of meiofauna was surveyed from six stations in sand mining area near around Sungapdo, Taean five times from April-December, 2007. Ten meiofaunal taxa in total, comprising 5-9 taxa per station were recovered. Nematodes were dominant from four stations in April and from five stations in May. In June, copepods were dominant from all stations except station two, from which sarcomastigophorans were predominant. Copepods were also dominant from three stations in October and four stations in December. The mean density of meiofauna per $10\;cm^{-2}$ was the highest in October (130 individuals) and lowest (68 individuals) in April. Meiofauna mean biomass per $100\;cm^{-2}$ was $3.80-75.26{\mu}gC$ from each station, with the monthly mean biomass being lowest in April ($11.97{\mu}gC$) and highest in October ($39.50{\mu}gC$). The highest biomass was recorded at station five in October ($75.26{\mu}gC$). Eleven families of harpacticoid copepods occurred Ameiridae and Ectinosomatidae were the most frequent. The mean diversity index was 1.21 from all the stations, 1.22 from the sand mining stations, and 1.19 from the reference stations. The nematode:copepod (N/C) ratio was 1.57 from the sand mining stations and 1.37 from the reference stations. Non-metric multidimensional scaling analysis divided the community into group A (station one, non-sand mining and reference area) and groups B and C in the sand mining area. The present study reports similar numbers of taxa but lower density and biomass of meiofauna compared to previous studies in Korean waters. The variability of the diversity index and N/C ratio may indicate large fluctuation of meiofauna depending on temporal and spatial conditions of the environment in the study area.

Spatial and Temporal Changes of Fish Community in the Cheonggye Stream after the Rehabilitation Project (복원된 청계천에 서식하는 어류군집의 시공간적 변화)

  • Choi, Jun-Kil;Byeon, Hwa-Kun;Kwon, Yong-Su;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • v.41 no.3
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    • pp.374-381
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    • 2008
  • Spatial and temporal changes of fish communities were studied at four study sites in the Cheonggye Stream from October 2005 to August 2006 after the rehabilitation process. During the survey period, 19 species in 6 families were sampled. Species Rhynchocypris oxycephalus and Zacco platypus were identified as dominant species. Korean endemic species such as Acheilognathus yamatsutae and Zacco koreanus were observed in the sites. Overall, species richness and abundance increased as time passes after the rehabilitation, reflecting colonization process of the fish community. Meanwhile species richness and abundance were higher at the downstream than at the upstream. Community indices such as dominant index, richness index and diversity index showed also similar spatial and temporal pattern. Nonmetric multidimensional scaling (NMDS), multivariate ordination technique, was used to analyze spatial and temporal variation of the fish communities, and the results showed spatial variation of fish communities with high species richness at downstream as well as the temporal variation of fish communities with high values of species richness and diversity index at later part of the study period, presenting colonization process of the fish community after the rehabilitation project.

Genetic Contribution of Indigenous Yakutian Cattle to Two Hybrid Populations, Revealed by Microsatellite Variation

  • Li, M.H.;Nogovitsina, E.;Ivanova, Z.;Erhardt, G.;Vilkki, J.;Popov, R.;Ammosov, I.;Kiselyova, T.;Kantanen, J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.5
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    • pp.613-619
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    • 2005
  • Indigenous Yakutian cattle' adaptation to the hardest subarctic conditions makes them a valuable genetic resource for cattle breeding in the Siberian area. Since early last century, crossbreeding between native Yakutian cattle and imported Simmental and Kholmogory breeds has been widely adopted. In this study, variations at 22 polymorphic microsatellite loci in 5 populations of Yakutian, Kholmogory, Simmental, Yakutian-Kholmogory and Yakutian-Simmental cattle were analysed to estimate the genetic contribution of Yakutian cattle to the two hybrid populations. Three statistical approaches were used: the weighted least-squares (WLS) method which considers all allele frequencies; a recently developed implementation of a Markov chain Monte Carlo (MCMC) method called likelihood-based estimation of admixture (LEA); and a model-based Bayesian admixture analysis method (STRUCTURE). At population-level admixture analyses, the estimate based on the LEA was consistent with that obtained by the WLS method. Both methods showed that the genetic contribution of the indigenous Yakutian cattle in Yakutian-Kholmogory was small (9.6% by the LEA and 14.2% by the WLS method). In the Yakutian-Simmental population, the genetic contribution of the indigenous Yakutian cattle was considerably higher (62.8% by the LEA and 56.9% by the WLS method). Individual-level admixture analyses using STRUCTURE proved to be more informative than the multidimensional scaling analysis (MDSA) based on individual-based genetic distances. Of the 9 Yakutian-Simmental animals studied, 8 showed admixed origin, whereas of the 14 studied Yakutian-Kholmogory animals only 2 showed Yakutian ancestry (>5%). The mean posterior distributions of individual admixture coefficient (q) varied greatly among the samples in both hybrid populations. This study revealed a minor existing contribution of the Yakutian cattle in the Yakutian-Kholmogory hybrid population, but in the Yakutian-Simmental hybrid population, a major genetic contribution of the Yakutian cattle was seen. The results reflect the different crossbreeding patterns used in the development of the two hybrid populations. Additionally, molecular evidence for differences among individual admixture proportions was seen in both hybrid populations, resulting from the stochastic process in crossing over generations.

Seasonal Variations in the Species Composition of Fisheries Resources Caught by Trammel Net in the Uljin Marine Ranching Area, East Sea (울진바다목장에서 자망으로 어획된 수산자원의 종조성과 계절변동)

  • Yoon, Byoung Sun;Park, Jeong-Ho;Yoon, Sang Chul;Yang, Jae Hyeong;Lee, Sung-Il;Kim, Jong-Bin;Choi, Young-Min;Sohn, Myoung Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.6
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    • pp.947-959
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    • 2015
  • Variations in the species composition, biomass and size distribution of fisheries resources in the Uljin marine ranching area were investigated using trammel nets at two stations (artificial reef and natural rocky area) from 2009 to 2010. During the survey, a total of 74 species were sampled with a mean density of 132 ind./net and mean biomass of 21.56 kg/net. In the natural rocky area, a total of 45 species were sampled at a mean density of 202 ind./net and mean biomass of 28.81 kg/net, while in the artificial reef area, samples included a total of 56 species, with means of 62 ind./net and 14.30 kg/net. The dominant species, comprising over 3% of the total number of individuals, were Suberites ficus (30.8%), Ovalipes punctatus (19.2%), Paralichthys olivaceus (11.7%), Pleuronectes herzensteini (4.7%), Kareius bicoloratus (3.5%), Pseudopleuronectes yokohamae (3.5%) and Eopsetta grigorjewi (3.0%). The dominant species, in terms of biomass, comprising over 5% of the total biomass, were P. olivaceus (22.1%), S. ficus (18.7%), O. punctatus (7.2%), Hexagrammos otakii (6.6%), P. yokohamae (5.7%), K. bicoloratus and P. herzensteini (5.3%). A cluster analysis and non-metric multidimensional scaling (nMDS) analysis based on the Bray-Curtis similarity of fourth root transformed data for number of species and individuals, was divided into two groups: the artificial reef area (group A) and the natural rocky area (group B).

Exploring the Class Observation and Nomination System for the Identification of Gifted Students Using a Concept Mapping Approach (영재교사들이 지각하는 관찰-추천 영재판별 시스템의 방향, 중요도, 실행수준 분석: 개념도 연구법을 활용하여)

  • Han, Ki-Soon;Lee, Jeong-Yong
    • Journal of Gifted/Talented Education
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    • v.21 no.1
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    • pp.107-122
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    • 2011
  • The purpose of this study is to explore the perception of the observation and nomination system for the identification of the gifted and to find out the importance and practice level perceived by the gifted education teachers using the concept mapping approach. For this, twelve gifted education teachers brainstormed and gathered ideas for the ideal ways of observation and nomination system and the gathered statements were solicited. Multidimensional scaling and hierarchical cluster analysis were also used. In addition, 112 gifted education teachers rated the importance of and the practice level for the suggested ideas of observation and nomination system. Results were as follows: First, 36 statements were solicited and as a result of concept mapping the suggested observation and nomination system were categorized as 'attainment of professionality', 'attainment of administrative support', 'attainment of fairness', and 'considering points for recommendation.' Second, there were significant differences between the perceived importance levels and the practice levels. Based on the results, imlications of the study were discussed in depth.

Seasonal Variation of Larval Fish Community in Jinhae Bay, Korea (진해만 자어 군집의 계절 변동)

  • Moon, Seong Yong;Lee, Jeong-Hoon;Choi, Jung-Hwa;Ji, Hwan Sung;Yoo, Joon-Taek;Kim, Jung-Nyun;Im, Yang Jae
    • Korean Journal of Environmental Biology
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    • v.36 no.2
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    • pp.140-149
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    • 2018
  • Seasonal variations in the community structure of larval fish assemblage in Jinhae Bay were investigated in February, May, August and November of 2015, and in the same months in 2016. During the study period, a total of 28 larvae species belonging to 24 families were collected. The dominant species were Clupea pallasii, Liparis tanakae, Callionymidae sp., Sillago japonica, Ernogrammus hexagrammus and Engraulis japonica. These six species accounted for 77.6% of the total number of larvae during the survey period. The larvae of C. pallasii and L. tanakae were exclusively caught in February 2015 and 2016, while those of Apogon lineatus and Sillago japonica were exclusively caught in August 2015 and 2016. Overall, species diversity of the fish larvae was highest in February and August, although it was relatively low in May. The results of the non-metric multidimensional scaling (nMDS) analysis using the number of individual larval fish showed that they are divided into four seasonal groups. Our results showed that the community of larval fish in Jinhae Bay was affected by seasonal changes in temperature and the emergence of spawning fish species. Additionally, we suggest that the high abundance of larval fish came from around Jam-do and the northern part of Chilcheon-do; these locations are the main spawning grounds of Jinhae Bay.

Fish Community Structure of the Former Channel Isolated by Channelization in the Mangyeong River, Korea: Implications for Connectivity Restoration (만경강에서 하천정비에 의하여 격리된 구하도의 어류 군집 구조: 연결성 복원을 위한 제안)

  • Kim, Seog Hyun;Cheon, Hyoung Tae;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
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    • v.2 no.1
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    • pp.22-32
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    • 2015
  • This study investigated the difference in fish community structures in a main channel and an isolated former channel, considering the environmental factors in the Mangyeong River, Korea. Principal component analysis (PCA) with environmental factors showed that former channels were composed of a fine substrate covered by in-stream vegetation, whereas the main channel was covered by a wide range of substrates with a higher dissolved oxygen and conductivity. The result of the hierarchical cluster analysis with species abundance delineated to the four main groups; three abandoned channel groups and one main channel group. Non-metric multidimensional scaling (NMDS) showed that fish community structures of each study site differed from environmental factors: former channel fish communities were positively related to in-stream vegetation cover, whereas main channel fish communities were positively associated with dissolved oxygen and conductivity. The results indicated that channelization, where there was a separation between the former channel and the main channel, had detrimental effects on fish community structures of both the main channel and the abandoned channel in the Mangyeong River. In conclusion, this study suggested that the connectivity between the main channel and abandoned channel were required to enhance both habitat structural diversity and species diversity of the Mangyeong River.

Community Structure and Understory Vegetation Distribution Pattern of Fagus engleriana Stand in Is. Ulleung (울릉도 너도밤나무림의 군집구조와 하층식생의 분포특성)

  • Cheon, Kwang-Il;Jung, Sung-Cheol;Lee, Chang-Woo;Byeon, Jun-Gi;Joo, Sung-Hyun;You, Ju-Han;Lee, Seul-Gi;Choi, Cheol-Hyun;Park, In-Hwan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.4
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    • pp.81-95
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    • 2012
  • This study was intended for Fagus engleriana stand in Is. Ulleung where the disturbance of vegetation has been caused by the exploitation and the increase of tourists. For the effective conservation and management on this issue, this study was conducted provide basic data. The sixteen study sites ($20{\times}20m$) were installed in the dominant Fagus engleriana stand and the base environment and vegetation were investigated. The Fagus engleriana stand was classified into two groups, The Fagus engleriana stand was classified into two groups, community A is Fagus engleriana-Sorbus amurensis and community B is Fagus engleriana-Acer pictum subsp. Mono by cluster analysis and community A were nothing signigicant by indicator species analysis. Community B were Eight species (Tsuga sieboldii, Camellia japonica, Dystaenia takesimana ect.) significant by indicator species analysis. The diameter class of 16cm to 25cm was 53.7% in population structure of Fagus engleriana, which was the highest and showed inverse J-distribution. Species diversity index (H') of investigated woody layer group ranged from 0.99 to 2.05 and that of under layer group ranged from 1.75~2.59. According to Non-metric Multidimensional Scaling (NMS) analysis, the woody layer was divided into community A developed in the region having relatively high sand content at high altitudes and community B formed at the place having relatively high clay content at low altitudes. Then this classification was significant through Multi-Response Permutation Procedures (MRPP) analysis. The distribution of understory vegetation through Detrended Correspondence Analysis (DCA) was induced by the silt content and cover degree of vegetation layer.

Seasonal variations in species composition of fish assemblage collected by trammel net in coastal waters of the East Sea (동해 연안 자망에서 채집된 어류 종조성의 계절변동)

  • Choi, Kwang Ho;Han, Moon Hee;Kang, Chang-Keun;Park, Joo Myun;Choi, Jung Hwa;Park, Jeong-Ho;Sohn, Myong Ho;Baeck, Gun Wook;Choy, Eun Jung;Lee, Chung Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.415-427
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    • 2012
  • Seasonal variation in species composition and abundance of fish assemblage in the north coast (NC: Ayajin) and central coast (CC: Hupo) of the East Sea were calculated using samples collected by trammel net during 2011-2012. A total of 20 species from NC and 17 species from CC were collected. Of the fishes collected, the dominant fish species were Glyptocephalus stelleri and Careproctus rastrinus in the NC, and Dasycottus setiger and G. stelleri in the CC. These 2 fishes accounted for 71.7% and 81.0% of the total number of individuals collected in the NC and CC, respectively. The number of fish species, number of individuals, biomass and species diversity indices fluctuated with the seasons. The cluster analysis and non-metric multidimensional scaling (MDS) based on Bray-Curtis similarity revealed that the fish assemblages classified into north and central groups. Analysis of similarity percentages of species contributions (SIMPER) indicated that most individual of G. stelleri and Gadus macrocephalus contributed to north group, and D. setiger and G. stelleri in central group, whereas 15 species contributed to 90% of the dissimilarity.