• Title/Summary/Keyword: Dominant index

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Seasonal Variability of Marine Algal Flora and Community Structure at Gumgap, Jindo, on the Southwestern Coast of Korea (한국 남서해안 진도군 금갑의 해조상 및 군집구조의 계절 변화)

  • Yoo, Hyun-Il;Heo, Jin-Suk;Choi, Han-Gil
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.1
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    • pp.300-307
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    • 2015
  • Seasonal variation in marine macroalgal community structure was examined at the intertidal zones of Geumgap, Jindo, Korea, from October 2013 to August 2014. In total, 56 macroalgal species were identified, including 9 green, 12 brown, and 35 red algae. Annual seaweed biomass was 548.96 g wet wt. /$m^2$ with seasonal range between 371.08 g wet wt. /$m^2$ at summer and 32.91 g wet wt. /$m^2$ at winter. The dominant seaweed in terms of biomass was Sargassum thunbergii and subdominant species were Gelidium elegans, Sargassum fusiforme, and Ishige okamurae. The vertical distribution of seaweeds from the upper to lower intertidal zones was Gloiopeltis spp., Ulva spp.- S. thunbergii, S. fusiforme, Ishige okamurae - S. thunbergii, S. fusiforme, G. elegans. Annual seaweed coverage, richness index (R), evenness index (J'), and diversity index (H') values were 27.95%, 6.10, 0.38, and 1.38, respectively. Coarsely branched form was the most dominant functional group in terms of species number and biomass among benthic macroalgal species.

Species Composition of Ichthyoplankton off Dokdo in the East Sea (독도 주변해역 부유성 어란과 자치어의 종조성)

  • Shin, Ui Cheol;Yoon, Seokjin;Kim, Jin-Koo;Choi, Gwangho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.4
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    • pp.498-507
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    • 2021
  • Ichthyoplankton (fish eggs and larvae) were collected seasonally collected from 2017 to 2019 to clarify whether Dokdo serves as a fish spawning and/or nursery ground. Fish eggs were identified and classified into 16 species. The dominant fish egg species were Engraulis japonicus, Maurolicus japonicus, and Parajulis poecilepterus. Fish larvae were identified and classified into 15 species. The dominant fish larvae species were E. japonicus, M. japonicus, and Sebastes owstoni. A cluster analysis similarity percentages revealed two distinct groupings according to sample location (stations) with E. japonicus and M. japonicus as the main group influencers. E. japonicus was the dominant species off Dokdo. The species diversity and abundance peaked in summer. The diversity index, richness index, and evenness index fluctuated seasonally. There were no predominant species variations among the years. Sedentary species such as P. poecilepterus, Semicossyphus reticulatus, and Glyptocephalus stelleri occurred in the inshore stations. E. japonicus, M. japonicus, and Trachipterus trachypterus occurred in the offshore stations. Our results show these species use Dokdo as spawning and nursery grounds.

The Vegetation and Ecological Characteristics of Warm Temperate Forest in Dalma Mountain, Haenam (해남 달마산 상록활엽수림 식생과 생태적 특성)

  • Cho, Ji-Woong;Lee, Kye-Han
    • Journal of Environmental Science International
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    • v.31 no.2
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    • pp.181-193
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    • 2022
  • The study was conducted to provide basic data for stable forest management according to climate change by identifying the ecological characteristics of Mt. Dalma warm temperate forest. 30 survey plots were established for vegetation structure analysis, and communities which classified by applying TWINSPAN analysis and DCA analysis techniques. Four plant communities were subdivided into Quercus acuta-Eurya japonica community, Quercus acuta community, Quercus salicina-Camellia japonica community, and Quercus acuta-Camellia japonica community. The tree layers were dominated by Quercus acuta and Quercus salicina, and the subtree layers were dominated by Camellia japonica and Eurya japonica, and the Sasa borealis. The species diversity index were in the range of 0.849 to 0.969, and the degree of Evenness index were 0.514 to 0.569, and the similarity index were 59.57 to 75.47%. The species composition in the community indicated that the deciduous broad-leaved and coniferous trees have already been eliminated in competition with evergreen broad-leaved trees. Tree species with good cold resistance such as Quercus acuta and Quercus salicina were dominant species under current climatic conditions, but the dominant species might be changed to more shade-tolerance evergreen broad-leaved through the succession.

A Comparison of the Plant Community Structures in the Burned and Unburned Areas of Mt Kumo-san (금오산에서 산회지와 비산화지의 식물군집구조 비교)

  • Kim, Woen;Sung, Kyung-Hee
    • The Korean Journal of Ecology
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    • v.19 no.1
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    • pp.55-64
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    • 1996
  • This is a report on the recovery of vegetation and secondary succession in the burned area studied from April, 1990 to April. 1991. The forest fire occurred in a part of Mt. $K\v{u}mo-san$ on April, 1986 and the pine forest and its understory vegetation were burned out completely. The floristic compositions of burned (B) and unburned (U) areas were composed of sixty eight and thirty one species (vascular plants), respectively. These species were divided into invaders (47 species), increasers (15 species), deceasers (3 species), neutrals (3 species), and retreaters (10 species) on the basis of summed dominance ratio ($SDR_3$). Biological spectra showed the $H-D_1-R_5-e$ type in both the burned and unburned areas. The species of Lespedeza ($SDR_3$=94.7), Miscanthus (91.95), Festuca (68.33), and Spodiopogon (52.06) were dominant in the burned areas, while the species of Pinus (76.67), Robinia (56.25), Quercus (52.08), and Carex (40.25)were dominant in the unburned area. Dominance index (C) in burned and unburned areas was 0.15 and 0.25, respectively. the index of similarity (CCs) was 0.42. The degree of succession (DS) and species diversity (H) in burned and unburned areas were 675.8, 884.2 and 4.07, 2.05, respectively. The degree of succession in the burned area graduall increased and the burned area was recovered to be simmilar to the unburned area. Evenness index in burned and unburned areas was 0.965 and 0.595, respectively.

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An Analysis of the Environmental Index and the Distribution of Naturalized Plants in Large Rivers of Downtown Gwangju Metropolitan City (광주광역시 도심 대규모 하천의 귀화식물 분포 및 환경지수 분석)

  • Lim Dong-Ok;Ryu Youn-Mi;Hwang In-Chun
    • Korean Journal of Environment and Ecology
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    • v.18 no.3
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    • pp.288-296
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    • 2004
  • This study was conducted from March to October 2003 to investigate the distribution status and environmental index of naturalized plants at 14 sites at rivers penetrating the downtown area of Gwangju Metropolitan City. The flora consisted of 309 taxa, 76 families, 211 genera, 273 species, 35 varieties and one form, while the naturalized plants consisted of 46 taxa, 14 families, 36 genera, 44 species and two varieties. The dominant species of Gwangju-cheon were nine taxa. Panicum dichotomiflorum, Rumex crispus, Chenopodium album, Trifolium repens, Veronica persica, Ambrosia artemisiifolia var. elatior, Aster pilosus, Bidens frondosa and Taraxacum offici-nale. The dominant species of Hwangryong River were five taxa: Rumex crispus, Trifolium repens, Oenothera odorata, Ambrosia artemisiifolia var. elatior and Erigeron canadensis. At Yeongsan River appeared 16 dominant species: Patspalum distichum, Ckenopodium ficifolium, Lepidium apetalum, Erigeron annuus and Xanthium strumarium in addition to the same dominant species of Gwangju-cheon and Hwangryong River The Urbanization Index (UI) was 17.2% and the Naturalized Index (NI) was 14.9% at urban rivers of Gwangju. The naturalized plants consisted of 16 taxa, which originated in both Europe and North America. Based upon the UI and NI, the urban rivers and their riversides must be considered a major corridor for the invasion of naturalized plants.

Effects of Thermal Effluents from Wolseong Nuclear Power Plant on Macroalgal Composition and Community Structure (월성원자력발전소 온배수가 해조류 종조성 및 군집구조에 미치는 영향)

  • Choi, Han-Gil
    • ALGAE
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    • v.23 no.2
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    • pp.151-162
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    • 2008
  • Marine algal flora and community structure were seasonally examined at three sites in the vicinity of the Wolseong nuclear power plant in Korea from February to November 2006. A total of 126 seaweeds including 25 green, 31 brown, 70 red algae, and 1 marine plant were identified. The greatest number of species occurred at Jeonchonri (101 species) followed by intake (88 species) and discharge (29 species) during the study period. Of 126 seaweeds, 76 annuals and 13 warm tolerance species were recorded. Dominant species based on important value (IV > 10) were Ulva pertusa and Enteromorpha linza at intake, U. pertusa and Padina arborescens at discharge, and Sargassum horneri and Corallina pilulifera at Jeonchonri shore. Annual average biomass exhibited a wide range of variations, from 40.67g m-2 in dry weight at discharge to 133.69g m-2 at Jeonchonri. Among six functional groups, dominant group was coarsely-branched form at intake and Jeonchonri, but it was different at discharge site as filamentous form. Seaweed community structures of discharge site were distinguishable in decreasing species richness, biomass, species diversity index (H’), richness index (R), and evenness index (J’). Also, the ratios of green algae, warm tolerance species, annual algae, filamentous form and dominance index (DI) remarkably increased. Such phenomenons of discharge site are usually found under environmentally stressful conditions such as high disturbance. Thus, I can conclude that the heated effluents of nuclear power plant act as environmental stress influencing seaweed community structures and it can be detected with various community indices.

A Study for Plant Community Structure Analysis in Sangwonsa(Temple) Valley, Yongmunsan(Mt.) (용문산 상원사계곡 식물군집구조 분석)

  • Kim, Jong-Yup;Ki, Kyong-Seok;Min, Geon-Young
    • Korean Journal of Environment and Ecology
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    • v.26 no.5
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    • pp.758-769
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    • 2012
  • This study is aimed at analyzing the structural characteristics of vegetation in the Sangwonsa(Temple) valley, Yongmunsan(Mt.), and to collect basic data for research of large mountains which are located in the temperate, central region. The research on the entire vegetation struc trees are distributed over a wide area, accounting for 75.0% of theture of Sangwonsa(Temple) valley observed that oak total vegetation in the area. We examined 17 plots(unit area: $400m^2$) in the deciduous forest, dividing the trees into 5 community types based on the average important value. The 5 community types are as follows: A mixed dominant group of Carpinus laxiflora and Quercus serrata, a mixed dominant group of Quercus serrata and Quercus variabilis, a mixed dominant group of Quercus mongolica and Quercus serrata, a dominant group of Quercus serrata, a dominant group of Acer pictum supsp. mono. It is expected that the oak trees competing with Carpinus laxiflora and Acer pictum supsp. mono would flourish in a deciduous forest. The Shannon's species diversity index(H') was 0.3708~1.3083.

Fish Community and Stream Health Assessment in Lake Chungju and its Tributaries (충주호의 어류상과 유입하천의 생태건강성 평가)

  • Choi, Myung-Jae;Park, Hae-Kyung;Yun, Seuk-Hwan;Lee, Jangho
    • Journal of Korean Society on Water Environment
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    • v.28 no.2
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    • pp.185-196
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    • 2012
  • The fish community within the lake and 5 tributaries of Lake Chungju in spring and autumn, 2009 was surveyed. In this study, the total 128,506 individuals were collected belonging to 11 families 29 genera 34 species. The most dominant species was Squalidus japonicus coreanus that account for 91.6% of population and 49% of biomass of fish community. In the point of population, dominant species were small-sized species, which became the prey of big-sized predatory species. In the point of biomass, dominant species were predatory species which were large-sized. The most dominant species in lacustrine area was S. japonicus coreanus which accounted for 92.2% of total population and 49.1% of total biomass. The most dominant species of tributary streams was Tridentiger brevispinis which accounted for 66.4% of total population and 55.1% of total biomass. The site of C3 in lacustrine area and Dongdal-cheon in tributary streams collected the most number of species. Through ecological health evaluation of five tributary streams using 8 metric index of biological integrity (IBI) model, two streams (Dongdal-cheon, Kwang-cheon were evaluated as, "B", "good" condition, and Jangsung-cheon obtained grade C indicating "Fair" condition, Jecheon-cheon obtained grade D indicating "Poor" condition based on IBI model. Lepomis macrochirus which was designated as a domestic ecosystem-disturbing alien species with wide food niche have shown tendency to increase the number of individuals since 1991 indicating the adverse effect on not only fish community but also aquatic ecosystem food web of Lake Chungju.

Ecological Studies on Several Forest Communities in Kwangnung. A Study of the Site Index and the ground vegetation of Larch (광릉삼림의 생태학적 연구 낙엽송의 Site Index와 임상식생에 관하여)

  • 차종환
    • Journal of Plant Biology
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    • v.9 no.1_2
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    • pp.7-16
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    • 1966
  • In order to determine the factors related to site quality, 13 areas of Larch growing in the Kwangung and its vicinity forest as sample plots, were examined. Sample plots included various site classes as well as age classes. Three were divided into two groups (major and minor trees). Average height of dominant trees was determined through messurement of 5 to 6 dominant tree in each sample plots. Average height of dominant 30 year-old trees was the basis for site index. A Standard Yield Table for the larch produced in Kwangnung forest was made by various data, which included age class 5, ranging from 10 to 45 years. The relationship of the height of the trees, the site conditions, and ground vegetation are investigated in this paper. The site indexes of 40 forest class age in 28-B and 28-G forest classes of the larch associations for ground vegetation had comparatively rarge differences due to the sampled areas. The relation of the direction of forest communities to the height and the diameter of the tree shwoed that its communiteis of northest and northwest parts appeared higher valueof the height and the diameter. The diameter and the height of trees were closely realted to each other. The samller the occupied area per tree and the smaller the average distance among trees, the more density was increased. The larger the density was the lower height of the trees. In the ground vegetation of the larch communities, there seems to be a definite correlation between the height of trees and the occupied area per tree or the average distance among the trees. The height of trees and site index of two larch communities were as follow: 28-B forest class site index 20.8, height 24.0m, 28-G forest class site index 18.4, height 20.9m. The ground layer was analyzed by the method of Quadrat(20/20sq. cm) with an interval of 1M. It set up 40 Quadrats of the larch communiteis. The community structure of the ground vegetation of two larch was analyzed, and important value was calculated and then evaluated. The ground vegetation under the larch had developed Burmannii Beauv stratal society below the 28-B and 28-G the forest class. Accordingly, the first important value of Burmannii Beauv was found in two ground vegetation below the larch. Therefore, this species could be quantitatively considered as the forest indicator species. Common species of each community appeared 18 species out of 34 species in the ground vegetation under two larch communities. The ground vegetation of the 28-B forest class showed more than that of the 28-G forest class. the similarity of the ground vegetation was measrued by the Frequency Index Community Coefficient. The differences between the associations were lcearly manifested by the ground vegetation tested by Gleason's Frequency Index of Community Coefficient for the analysis of each stratal society of all associations. According to F.I.C.C. the ground vegetation under two larch(28-B and 28-G) forest classes showed higher value. An investigation into the relationship of physical and chemical properties of soil and site was considered the next step to be taken in the study of the larch site classification.

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Comparison of Fish Distribution Characteristics by Substrate Structure in the 4 Streams (하상구조에 따른 4개 하천의 어류 분포 특성 비교)

  • Yoon, Seok-Jin;Choi, Jun-Kil;Lee, Hwang-Goo
    • Korean Journal of Environment and Ecology
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    • v.28 no.3
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    • pp.302-313
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    • 2014
  • This study was conducted to compare the characteristics of fish distribution according to sand type stream and cobble type stream the 4 stream selected every season. The collected Korea endemic species during the survey period were 24, including Acheilognathus gracilis. Dominant species of Hongcheon stream and Muju Namdae stream was Zacco koreanus, each accounting for 39.9% and 28.4% in order, and dominant species in Yanghwa stream was Rhodeus notatus, 13.6%, and those in Gap stream was Z. platypus, by 26.0%. As a result of community analysis, dominant index was 0.27~0.63, diversity index was 1.92~2.67, evenness index was 0.6~0.79, richness index was 3.09~3.53, and dominant index was the highest in Hongcheon stream, and the indices of diversity, evenness and richness were the highest in Yanghwa stream. As a result of tolerance guild analysis, Hongcheon stream and Muju Namdae stream with a variety of substrates accounted for relatively higher rate by 50.1% and 46.4% in sensitive species respectively, and Yanghwa stream and Gap stream with greater sand substrates had 0.5% and 5.3% scarce rate of sensitive species. As a result of similarity analysis using the species, population and substrate structures of the fisheries appeared in each stream, cobble type streams such as Hongcheon stream and Muju Namdae stream were the most similar by 50.4% in species and population, 95.2% in bed structure. As a result of IBI analysis, Hongcheon stream and Muju Namdae stream appeared as 'Class A,' Yanhwa stream and Gap stream as 'Class B' and the two groups of cobble type stream and sand type stream were divided as a result of principal components analysis.