• Title/Summary/Keyword: evenness

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Faunal Assemblages of Benthic Macrofauna in the Inter- and Subtidal Region of the Inner Kyeonggi Bay, West Coast of Korea (서해 경기 내만해역 조간대, 조하대의 저서동물군집)

  • Shin, Hyun Chool;Choi, Jin Woo;Koh, Chul Hwan
    • 한국해양학회지
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    • v.24 no.4
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    • pp.184-193
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    • 1989
  • An investigation on the soft-bottom macrobenthic community in the inner Kyeonggi Bay was conducted in July, October of 1987 and February, May of 1988. The benthic fauna comprised a total of 87 species and showed mean density of 550 indiv./$m^2$. Major faunal groups are polychaetes, molluks, and crustaceans, corresponding to 64.7%, 17.4%, and 15.2% in total abundance respectively. The most abundant species was Tharyx sp. (10.9%), and followed by Mactra veneriformis (10.5%), Mediomastus sp. (8.6%), and Glycinde sp. (8.0%) etc.. The important species in the intertidal zone were Mactra veneriformis, Hinia festiva, and Nephtys californiensis, whereas those in subtidal channel region were Tharyx sp., mediomastus sp., Sternaspis scutata, and Nephtys polybranchia. The study area could be divided into 4 station groups based on the species composition; two groups within interidal flat and two in channel regions. Each station group sustained its specific benthic faunal assemblage; Mactra-Hinia, Aricidea-Haploscoloplos assemblages in the intertidal flat and Harpiniopsis-Urothoe, Mediomastus-Sternaspis assemblages in the subtidal channel region. The Mediomastus-Sternaspis assemblage showed the highest species number and population density, and also did the highest diversity and evenness indices. The Harpiniopsis-Urothoe assemblage showed the poor species composition and abundance, and so recorded the highest dominance index. Two assemblages in the intertidal flat had the intermediate values in all the biological parameters. The northern channel region of zone S-2 showed the high abundance in species composition, which seems to be caused by the heterogeneous sediment and the organic enrichment from the Han River and the Incheon industrial complex.

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The Fish Fauna and its Community Stucture in the Nam River, Nakdong River System, Korea (남강의 어류상과 군집구조)

  • Yang, Hong-Jun;Kum, Ji-Don
    • Korean Journal of Ecology and Environment
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    • v.35 no.3 s.99
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    • pp.220-231
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    • 2002
  • The fish fauna and Community were surveyed from April 2000 to September 2001 at 23 stations in the nam river, the first tributary located to the lower reach of the Nakdong River system. During the study period, 39 species belonging to 29 genera and 11 families were collected. Of which 14 species are endemic species or subspecies in Korea. Introduced species from other river system, O. bidens had not been collected at all after the report of Yang (1973) but many individuals were captured at main stream and tributary in this survey. Introduced species from abroad M. salmoides increased at most of stations. Dominant species in main stream were Z. platypus, O. bidens and H. labeo. On the contrary, Z. temmincki, Z. platypus and S. gracilis majimae dominated the tributaries. Diversity indices of main stream and tributaries were 0,979 and 0.966 respectively. St. 3 of main stream and St.1 and 16 of tributaries had high diversity indices (1.05, 0.962, 0.956) and lower dominant indices (0.102, 0.369, 0.200). As a whole, dominant index was 0.160, diversity index 1.044 and evenness index 0.656. It indicated that the community structure of this river was stable and diverse relatively.

Distribution Characteristics of Fish Community to Stream Order in Namhan River Watershed (남한강수계의 하천차수별 어류군집 분포 특성)

  • Lee, Seung-Hyun;Lee, Hwang-Goo;Park, Sang-Jeong;Lee, Soo-Hyung;Choi, Jun-Kil
    • Korean Journal of Ecology and Environment
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    • v.47 no.spc
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    • pp.100-115
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    • 2014
  • For this study, we collected fishes of seven times at the 51 sites by stream orders (2-6) from November 2007 to September 2010. In the results, 55 species belonging 12 families were collected. And there were one species (1.8%) of Natural monument, 6 species (10.9%) of endangered and 22 species (40.0%) of Korea endemic. Dominant species was Zacco koreanus and subdominant species was Zacco platypus in whole. Stream orders (2-6) increased with increasing species, diversity (H'), evenness (EI), richness (RI), tolerant (TS), omnivore (OS) and decreasing individual, dominance (DI), sensitive (SS) insectivore (IS), total IBI score. Principal component analysis results showed location of variable (species, individual, community index, relative abundance of tolerant, sensitive, omnivore, insectivore species) and each site changes in upstream and down-stream changes in their distribution. Correlation analysis showed significant differences between stream orders (2-6) and variable (species: Sp, diversity index: H', omnivore species: OS, stream depth: SD, stream width: SW and water temperature: WT).

Survey and Analysis of Insect Species in the South Korea Habitat (Yeoncheon) of the Water Spider, Argyroneta aquatica (연천군 물거미 서식지의 곤충상 조사 및 군집분석)

  • Kang, Juwan;Park, Taechul;Park, Junyeong;Kim, Jihun;Jeong, Youngmoon;Park, Jung-Joon
    • Korean Journal of Environmental Biology
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    • v.35 no.4
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    • pp.476-491
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    • 2017
  • The water spider (Argyroneta aquatica), a rare member of its species, is one of the few insects known to live under water all over the world. In Korea, the water spider can be found only in the Eundae-ri, Yeoncheon, Gyeonggi province, where they are designated as a natural monument. However, loss of habitat is obvious, as the Eundae-ri wetland undergoes hydrarch succession. Loss of habitat has a direct impact on the water spider population. Thus protective measures for the water spider are needed to preserve the water spider habitat. In this study, a sweeping and visual survey of insect species was conducted in the water spider habitat from May to September 2015. The characteristics of each one of the different insect species and the community features were analyzed in this study. A total of 3,929 insects representing 276 species from 13 orders collected for the analysis. The most frequently collected insects from the Order Hemiptera represented 24.2% of total species and 82.3% of the total number of insects. Community analyses showed dominance, diversity, evenness, and richness indices of 0.23, 2.27, 0.41, and 31.2, respectively. Compared with the previous survey data, these results showed that reduction of the spider's wetland habitat caused the most commonly collected insects to adapt and spread to the surrounding terrestrial environment.

Ecological Characteristics of Forest Community by Distance from Camellia japonica Stand (동백나무림으로부터 거리별 산림군집의 생태적 특성)

  • Chung, Jae-Min;Jung, Hye-Ran;Kang, Jin-Taek;Kim, Chang-Hwan;Cho, Min-Gi;Moon, Hyun-Shik
    • Journal of agriculture & life science
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    • v.44 no.6
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    • pp.27-37
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    • 2010
  • This study was carried out to offer the basic information on ecological succession of evergreen broad-leaved forest through understanding of ecological characteristics of forest community by distance from Camellia japonica stand. Importance value of C. japonica at tree layer was highest in site I and those of Pinus densiflora and P. thunbergii were highest in site II, III and IV. At subtree layer, the importance value of C. japonica was highest in site I while Neolitsea sericea and Styrax japonica had the highest importance value in site II, III, and IV. In all sites, species diversity ranged from 0.121 to 0.515 and 1.112 to 1.589 at tree layer and subtree layer respectively. Evenness ranged from 0.811 to 0.930 at subtree layer, 0.796 to 0.913 at shrub layer and 0.155 to 0.727 at tree layer, this indicates that distribution pattern by species is more uniform at subtree and shrub layer than at tree layer. Soil pH was highest as 5.72 at site I. Contents of total N, organic matter and available P were higher at site I than other sites.

Ichthyofauna and Community Structure of Fish in Chuncheon and Andong Reservoirs (춘천호와 안동호의 어류상과 군집 특성)

  • Kim, Jin Hui;Kwon, Joon Yeong;Song, Jun Young;Oh, Yun Kyeong;Kim, Kwang Seog;Hur, Jun Wook
    • Journal of Marine Life Science
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    • v.4 no.2
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    • pp.70-80
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    • 2019
  • Ichthyofauna and community structure of fish were studied for two fisheries resource reserves, Chuncheon reservoir and Andong reservoir from 2017 to 2018. Fish were sampled 8 times at each reservoir. In Chuncheon reservoir, total number of fish sampled was 1,197 representing 34 species and 13 families. Dominant species and sub-dominant species were Lepomis macrochirus (23.2%) and Zacco platypus (17.4%), respectively. In Andong reservoir, total number of fish sampled was 1,393 representing 24 species and 9 families. Dominant species and sub-dominant species were L. macrochirus (15.7%) and Carassius carassius (15.2%), respectively. The diversity index of two sampling site increased compared to previous investigation. The evenness index was not changed much in Andong reservoir but increased in Chuncheon reservoir. Ichthyofauna and community structure of fish at sampling sites in both reservoirs maintained stable except high proportion of exotics species with needed to be reduced by consistent effort. For better fish population in these communities, however, various efforts such as seed stocking and installment of artificial spawning ground should be provided to these reservoirs.

A Community Characteristic on Benthic Macroinvertebrates and Correlation of Physicochemical Water Quality Factors in Stream of Gaya Mountain (가야산 수계 내 저서성 대형무척추동물의 군집특성과 이화학적 수질요인과의 상관관계)

  • Kim, Hyoung-Gon;Yoon, Chun-Sik;Cheong, Seon-Woo
    • Journal of Wetlands Research
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    • v.20 no.4
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    • pp.322-329
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    • 2018
  • In this study the community characteristics of benthic macroinvertebrates distributed in stream of Gaya Mountain were figured out and the correlation with the physicochemical water quality factors were calculated. During the study period, total 4 phyla, 6 classes, 13 orders, 36 families, 100 species of benthic macroinvertebrates were recorded. Ephemeroptera were the most dominant followed by Trichoptera, Plecoptera, Diptera, Non-insecta, Hemiptera, and Odonata. The overall dominant species was Cincticostella levanidovae by dominance rate in 17.72%, subdominant species was Hydatophylax nigrovittatus by dominance rate in 6.15%. The biotic indices showed the diversity index 5.17, richness index 12.44, dominant index 0.24 and evenness index 0.78, there is no absolutely dominant benthic macroinvertebrates in the stream of Gaya Mountain. We identified the correlation between the species number and individuals of main taxa and the physicochemical water quality factors. Ephemeroptera and Plecoptera showed a negative correlation with water temperature, but they represented a positive correlation with the dissolved oxygen. This results suggest that water temperature and dissolved oxygen are important physicochemical water quality factors affects the distribution of Ephemeroptera and Plecoptera, the indicators of clean water stream.

Change in Biodiversity and Community Structures in Agricultural Fields depending on Different Farming Methods (농법 차이에 따른 농경지 생태계의 생물 다양성 및 군집 구조의 변화)

  • Kim, Hoon;Kim, Kyo-Jin;Sun, Yan;Jo, Young-Ju;Kim, Tae-Yeon;Moon, Myung-Jin
    • Korean Journal of Organic Agriculture
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    • v.26 no.4
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    • pp.687-706
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    • 2018
  • Organic agriculture is well known to be not only affecting the physical and chemical status of the soil but also closely connected to the biodiversity through complex community structure and ecological interactions. Current study monitored and analyzed the invertebrate biodiversity of organic and conventional paddy fields and upland fields from April, 2017 to August, 2017. Total of 680 species (with 14,371 individuals) were confirmed - more number of species were identified at the organic agriculture practicing fields. According to the various indices analysis, organic paddy field showed about 40% higher diversity index, while organic upland field showed about 10% higher diversity index. Richness index at organic paddy field was 60% higher compared to conventional paddy field, while organic upland field showed 40% higher value. Dominance and evenness index at conventional agriculture practicing fields were low, which possibly indicate at least partial dominance phenomenon. Hemipteran, dipteran and aranean species showed highest diversity in all fields, while dipteran, hemipteran, aranean and coleopteran species had highest diversity in conventional agriculture practicing fields.