• Title/Summary/Keyword: Dominance index

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Macroalgal Community Structure on the Subtidal of Southern Six Islands, Korea (남해안 6개 도서의 조하대 해조류 군집구조)

  • Heo, Jin suk;Yoo, Hyun Il;Park, Eun jung;Ha, Dong Soo
    • Korean Journal of Environmental Biology
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    • v.35 no.4
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    • pp.595-603
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    • 2017
  • The macroalgal community structure was examined at the subtidal zones of six study sites, on the Southern coast of Korea from between May and August 2015. A total of 132 seaweeds, comprising 10 green, 28 brown and 94 red Seaweed, were identified. The seaweed biomass was $80.32g\;dry\;wt.\;m^{-2}$ in average, and it was maximal at Geomundo ($166.94g\;dry\;wt.\;m^{-2}$) and minimal at Byeongpungdo ($14.52g\;dry\;wt.\;m^{-2}$). On the basis of the biomass, the Ecklonia cava was a representative species, distributed widely in the subtidal zone of the three islands (Yeoseodo, Geomundo, Baekdo). Also, the Sargassum sp. was dominant at Sejondo and Hongdo. The turbidity and light transmittance was divided into two groups. The seaweed community structure of group A (Byeongpungdo, Sejondo, Geomundo) was characterized by high turbidity, low light transmittance and a lower habitat depth than were observed in group B (Hongdo, Baekdo, Yeoseodo). As the water depth increased, the biomass decreased due to the lowered light transmittance. In Byeongpungdo and Sejondo, which showed high turbidity and low light transmittance, the degree of seaweed coverage was decreased with the depth of water. The ESGII ratio of the Ecological Status Group was higher than fourty percentage in Byeongpungdo and Baekdo. Community indices were as follows: dominance index (DI) 0.35-0.90, richness index (R) 7.03-17.93, evenness index (J′) 0.22-0.60, and diversity index (H′) 0.79-2.18. The Macroalgal zonation of the subtidal zone was calculated by the Ecklonia cava and Brown algal population on five islands(Byeongpungdo, Yeoseodo, Geomundo, Beakdo, Hongdo). On the other hand, Undaria pinnatifida and Sargassum sp. dominated at Sejondo. Additionally, the biomass ratio and the species richness of green algae was lower in group A. These differences in the seaweed community structure may have resulted from the effects of turbidity and light transmittance.

A seasonal characteristic of fish assemblage in the coastal waters Gapa-do, southern part of Jeju Island (제주도 남부 가파도 연안 어류군집의 계절별 특성)

  • KO, Jun-Cheol;HAN, Song-Heon;KIM, Bo-Yeon;CHOI, Jung-Hwa;HWANG, Kang-Seok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.57 no.1
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    • pp.10-24
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    • 2021
  • A seasonal characteristic of fish assemblages in the coastal waters of Gapa-do was determined using samples collected by a trammel net from 2015 to 2019. Annual mean temperature and salinity were 18.9℃, 33.6 psu (2015), 19.5℃, 33.6 psu (2016), 18.9℃, 33.8 psu (2017), 18.8℃, 34.5 psu (2018) and 19.5℃, 33.7 psu (2019), which show a stable water mass. During the survey period, a total of 50 species (30 families and 8 orders) of fishes were identified, including Scorpaeniformes (3 families and 9 species) and Perciformes (18 families and 29 species) that accounted for 68% of the total number. The number of species was higher in summer than in winter, showing the peak in the summer by 35 species and the low in the winter by 20 species. The number of individuals and the biomass peaked in the summer by 690 individuals and 151.4 kg, and were the lowest in the autumn by 336 individuals and 76.6 kg. The annual diversity index, evenness index and richness index were appeared to be 2.54-2.75, 0.68-0.76 and 5.32-6.65 at each stations. The dominance index was appeared to be the highest in 2018 and the lowest in 2015. Marbled rockfish (Sebastiscus marmoratus), rock fish (Sebastes inermis), filefish (Stephanolepis cirrhifer), rabbit fish (Siganus fuscescens), porcupine fish (Diodon holocanthus) and smallscale blackfish (Girella melanichthys) were dominant species, which occurred abundantly during the entire survey period. Subtropical fishes were identified as a total of 24 species (48.0%) and the number of species was higher in 2019 by 20 (60.6%) species and lower in 2015 by 13 (44.8%) species. The dominant species of the subtropical fishes were appeared to be rabbit fish, porcupine fish, smallscale blackfish, flag fish (Goniistius zonatus), stripey (Microcanthus strigatus), grunter (Parapristipoma trilineatum), and bluestriped angelfish (Chaetodontoplus septentrionalis) at the study sites.

Characteristics of Fraxinus chiisanensis Distibution and Community Structure of Mt. Minjuji on Chungcheongbuk-do (충북 민주지산 물들메나무 분포 및 군락구조 특성)

  • Choi, Dong-Suk;An, Ji-Young;Oh, Choong-Hyeon
    • Korean Journal of Environment and Ecology
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    • v.35 no.6
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    • pp.632-643
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    • 2021
  • The objective of this study was to examine vegetation community structure and distribution of Fraxinus chiisanensis in Mt.Minjuji of Chungcheongbuk-do by setting up and surveying 8 plots (400 m2 each). Mean Importance Value (MIV) of Fraxinus chiisanensis in 8 plots was 35.19% in average (ranging from 26.07~42.74%). Since it is the dominant species in all plots, it is expected to maintain the present vegetation structure. The analysis of the DBH (diameter at breast height) showed that the diameter of Fraxinus chiisanensis in Mt.Minjuji ranges from 2 to 43cm. The majority of Fraxinus chiisanensis is expected to maintain current state unless disturbance or rapid environmental change occurs. The Species Diversity (H') was 0.8498~1.0261, Evenness (J') was 0.8160~0.9256, Dominance Index (D) was 0.0789~0.1840, Maximum Diversity (H'max) was 1.0414~1.2041. The analysis of annual ring and radial growth showed that the average age of Fraxinus chiisanensis in Mt.Minjuji was 29.1years(ranging from 22~58years). The average annual radial growth of Fraxinus chiisanensis was the highest in community G with 5.84mm and the lowest in community B with 2.80mm. The similarity index analysis revealed that the similarity index between community B and E, C and F, H was the highest with 69.0%, and the similarity index between community E and F was the lowest with 29.6%. Both the area of Fraxinus chiisanensis community of Mt.Minjuji and its population size are very small. Therefore, this area needs to be designated as Forest Genetic Resource Reserve.

The Structure Analysis of Plant Communities of Betula ermanii Community in Subalpine (아고산대 사스래나무군락의 식물군집구조 분석 연구)

  • Da-Um Yun;Choong-Hyeon Oh
    • Korean Journal of Environment and Ecology
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    • v.38 no.3
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    • pp.338-350
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    • 2024
  • A vegetation survey was conducted and analyzed on 25 survey plots of Betula ermanii communities in the subalpine zone of Mt. Gariwang, Mt. Balwang, Mt. Bangtae, and Mt. Hambaek in Gangwon-do. As a result of TWINSPAN and DCA analysis, the community was divided into a total of 3 communities: Betula ermanii-Quercus mongolica community(GroupI), Betula ermanii-Acer pseudosieboldianum community (GroupII), and Betula ermanii community(GroupIII). As a result of the vegetation structure analysis, Betula ermanii-Quercus mongolica community(GroupI) is located on the periphery of the Mt. Bangtae trail at altitude of 1,082~1,192m, and Betula ermanii-Acer pseudosieboldianum community(GroupII) is located on the ridges and slopes of Mt. Bangtae, Mt. Gariwang, and Mt. Hambaek at altitudes of 1,230~1,373m. Betula ermanii-Quercus mongolica community(GroupI) and Betula ermanii-Acer pseudosieboldianum community(GroupII) are currently dominated by Betula ermanii, but after long term, it is expected that they will transe to Quercus mongolica. The Betula ermanii community(GroupIII) is located the summit of Mt. Hambaek and the summit of Mt. Balwang at altitude of 1,428~1,464m. It is expected that the community will be maintained as Betula ermanii community, because Betula ermanii is very dominant, and so the next generation dominant species is maintained by Betula ermanii. Betula ermanii community generally appear above 1,000 m above sea level, and the higher the altitude, the more dominant the Betula ermanii are. As a result of the soil analysis, the soil characteristics shows a similar pattern to the subalpine belt of Daecheongbong Peak of Mt. Seoraksan and Banyabong Peak of Mt. Jirisan. As a result of the species diversity index analysis, the species diversity index was 1.210~1.293, the abundance index was 0.698~0.795, and the dominance index was 0.208~0.302.

Weed Dynamics in Hand - and Machine - Transplanted Lowland Rice (기계이앙답(機械移秧畓)과 손이앙답간(移秧沓間)의 잡초발생생태(雜草發生生態) 차이(差異))

  • Kim, S.C.;Choi, C.D.;Lee, S.K.
    • Korean Journal of Weed Science
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    • v.4 no.1
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    • pp.11-18
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    • 1984
  • The effect of transplanting method of rice seedlings on weed occurrence was investigated at the Yeongnam Crop Experiment Station in 1983. Rice was transplanted by hand and machine and eleven common herbicides were applied. The greatest weeds were harvested from the plot that rice was not transplanted and more weeds encountered at machine transplanted plot than hand transplanted plot. The degree of weed suppression by rice plant itself was 50% for machine transplatning and 55% for hand transplanting, respectively. Simpson index and community dominance of weed species were the highest in hand transplanting and followed by machine transplanting and no rice plot in order. Rice grain yield was exponentially correlated with the amounts of weed occurrence and more yield loss exhibited at machine transplanting than hand transplanting in the same amount of weeds. In the herbicidal activity, most of herbicides performed better at hand transplanting than machine transplanting while the degree of difference between transplanting methods varied depend on herbicide used.

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Seasonal and Spatial Variation of Polychaetous Community in Youngil Bay, Southeastern Korea (영일만 다모류 군집의 계절별, 공간적 변화)

  • 신현출;최성순
    • 한국해양학회지
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    • v.27 no.1
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    • pp.46-54
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    • 1992
  • An investigation on the benthic polychaete community in Youngil Bay was conducted during four seasons of 1991. Polychaetes. the dominant macrofaunal group occupying 71.3% in total macro-faunal density, comprised a total of 72 species with a mean density of 1,485 indiv. m/SUP -2/. The highest species number of 54 spp. and density of 3,207 undiv. m/SUP -2/ was recorded in summer, while the lowest in autumn. The most abundant species was Spiophanes nombyx (37.5%), followed by Pseudopolydora sp.(8.4%), Lumbrineris longifolia(7.0%), Madden cristata(6.5%), Polydora ciliata(4.9%) and so on. Maldane cristata was dominated in winter, Polydora ciliata in spring and Spiophanes bombyx in summer and autumn. The density and species number of Polychaetes were high in the southeastern area of Youngil Bay, and poor near the mouth of Hyoungsan River. Based on the species composition, study area was divided into three regions. Each region sustained its specific benthic faunal assemblage; Maldane-Praxillella assemblage from the middle to the southeastern region of Youngil Bay, Spiophanes-Nephtys assemblage in the northwestern region, and Pseudopolydora-Polydora-Capitella assemblage from the mouth of Hyoungsan River to Pohang Hobour. Maldane Praxillella assemblage showed the highest species number of 55 spp.. and the highest species diversity and species richness indices. Spiophanes-Nephtys assemblage had the highest density of 2,675 indiv. m/SUP -2/ and the highest dominance index because of the predominance of Spiophanes bombyx with a density of 2,073 indiv. m/SUP -2/. Pseudopolydora-Polydora-Capitella assemblage was found in the polluted area and it was a specific assemblage mainly composed of the dominance of organic pollution indicator species. The dominant Polychaetes were Pseudopolydora sp., Polydora ciliata, Capitella capitata, and Dorvillea sp.

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The Study of Forest Vegetation in Cryptomeria japonica D. Don Plantations (삼나무 인공조림(人工造林) 임분(林分)의 식생(植生)에 관한 연구(研究))

  • Lee, Jyung Seok
    • Journal of Korean Society of Forest Science
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    • v.69 no.1
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    • pp.42-50
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    • 1985
  • The vegetation of common Cryptomeria (Cryptomeria japonica D. Don) stands planted in Chonnam- province was investigated to obtain the fundamental informations for evaluation of suitable site and the improvement of managing method of the Cryptomeria stands in this region. The results investigated were summarized as follows; 1) The growth condition of common Cryptomeria planted 21-25-year-old stands was similar that of same species growing in Akidaken-district in Japan, while the growth condition of 51-58-year-old stands was not so good as that of Japanese. 2) Total number of plant species was 256. The number of floristic composition varied in the range of 42-99- species, which should be mere than those of Japanese. 3) The investigated sites were located in temperate southern part and in subtropic northern part of Korean peninsular. The types of understory vegetation were classified from I to IV class. 4) From the results of high max. possible diversity (H' max), and dominance (1-J') and from the low simple dominance (${\lambda}$) and evenness (J'), It could be concluded that vegetation was relatively in evenness. 5) From the low percent similarity, the specificity among the stands could be evaluated as considerable. 6) After the index of Morista, the 8th stand in Chang sung showed the generalized vegetation, while the 12th stand in Chang hung showed the specialized vegetation. 7) From the low values of Sneath-Sokal distance, the similarity among the stands investigated appeared very high.

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Distribution of Weeds in Greenhouses of Gyeongnam Area (경남지역(慶南地域) 시설원예작물(施設園藝作物) 재배지(栽培地)에 발생(發生)하는 잡초(雜草)의 분포(分布))

  • Lee, J.J.
    • Korean Journal of Weed Science
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    • v.16 no.1
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    • pp.1-7
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    • 1996
  • In order to get basic information for establishing weed control methods in greenhouse, weed distribution was surveyed at 42 greenhouses in 10 cities and counties of Gyeongnam and Junnam area from September to December, 1995. Sixty nine weed species in 23 families which were composed of 28 annuals, 16 biennials and 25 perennials were identified. Broadleaf weed species was 50 species, followed by 8 species in grasses, and 11 species in sedges. Cruciferae was the most widely occurring family belong to 9 species, followed by 8 species in Compositae, Cyperaceae and Gramineae, respectively, 6 species in Polygonaceae, and the other 17 families have 1~3 species. The dominant weed species occurred in greenhouses based on summed dominance ratio of weeds were Cardamine flexuosa var. fallax, Digitaria sanguinalis, Eleusine indica, Stellaria aquatica, Centipeda minima, Mollugo pentaphylla, Portulaca oleracea, Rorippa islandica.

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The relationship between brain dominance thinking type and empathy ability of nursing students (간호대학생의 두뇌 우성 사고 유형과 공감 능력 간의 관계)

  • Koo, Sang-Mee;Chang, Woo-Shim;Kim, Rae-Eun
    • Journal of Convergence for Information Technology
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    • v.11 no.9
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    • pp.157-164
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    • 2021
  • The purpose of this study was to elucidate the relationship between the brain dominant thinking type and empathy ability of nursing students. The subjects of this study were a total of 90 students enrolled in the 3rd year of the nursing department, who were subjected to Herrmann's BDI as a brain dominant thinking type test. The empathy test was conducted using the Interpersonal Response Index(IRI) adapted by Park(2004). For data analysis, Pearson correlation analysis and multivariate analysis were performed. As a result of the analysis, the dominant brain thinking type of nursing students was in quadrant C the most. And there was a statistically significant positive relationship between the brain dominance type and empathy in the C quadrant(r=.38) and D quadrant(r=.54). The overall empathy ability was highest in the D quadrant, and there was a statistically significant difference in the overall empathy ability according to the brain dominant thinking type(F=4.95, p<.01). Based on the results of this study, it is intended to be used in theoretical and practical education for nurse nurturing to improve empathy ability of nursing students.