• Title/Summary/Keyword: dominance species

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Analysis of Some Desert Ecosystems Vegetation in Abu Dhabi Emirate, United Arab Emirates. Effect of Land Use

  • Mousa, Mohamed Taher;Ksiksi, Taoufik Salah
    • Journal of Forest and Environmental Science
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    • v.25 no.1
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    • pp.49-55
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    • 2009
  • The present study analyses the effect of land use on the vegetation of some desert ecosystems in Abu Dhabi, United Arab Emirates (UAE). Three sites were selected to represent different types of land use, inside Umm Al-Banadeq forest, outside the forest and along Abu Dhabi-Al Ain Trucks Road. In total, fifty-two stands were examined; including a matrix of 14 species ${\times}$ 52 stands. Based on species cover data, stands were classified using TWINSPAN and ordinated using DCA. Four vegetation groups were generated at level three of classification. Zygophyllum mandavillei was dominant in most vegetation groups; Heliotropium bacciferum dominated vegetation groups inhabited the forest. Species richness, species turnover, relative evenness and relative concentration of dominance of forest vegetation groups were 2.8, 5.7, 0.7, and 2.0, respectively. The differences were attributed to both natural variability and forestry-induced changes, including change in land use, drainage and ploughing and shading by trees. Vegetation group inhabited Abu Dhabi-Al Ain Trucks Road, that were dominated by Haloxylon salicornicum and Zygophyllum mandavillei have high total cover (8.8 m per $m^{-1}$). Most community and vegetation attributes were significantly higher inside the forest than outside. Human interventions and environmental factors affected species diversity and abundance of these communities.

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Estimating the Population Size and Spatial Distribution of Three Scarites Species (Carabidae) in Sohwang Coastal Sand Dune Habitats, Boryeong, Korea

  • Do Sung Kim;Hyun Jung Kim
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.4 no.1
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    • pp.1-8
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    • 2023
  • In this study, we aimed to quantify the population size and spatial distribution of three predatory Scarites species in coastal sand dunes. In June and August 2014, 252 pitfall traps were utilized to conduct a trapping web analysis at three distinct sites with varying vegetation dominance values. Scarites sulcatus had the largest estimated population in a 10 m2 area with a habitat density of 36.6 in a Vitex rotundifolia community area (site B) in the June survey. In contrast, Scarites aterrimus had the largest population size with a habitat density of 2.9 in a Calystegia soldanella community area (site A) in the August survey. Spatial distribution analysis revealed that S. sulcatus dominated the Vitex rotundifolia community without preference for a particular site, whereas S. aterrimus and Scarites terricola pacificus were primarily observed on the beach. The results indicated that the three Scarites species in the Sohwang coastal sand dune region exhibited differences in their spatial and temporal distributions in the coastal dune ecosystem in order to avoid competition and predation. In conclusion, our findings can be utilized to estimate the population density of the genus Scarites on the Korean Peninsula. The outcomes of this study will contribute to estimating insect population densities on the Korean Peninsula and developing investigative assessment methodologies.

A Study on the Fish Community and Various Guilds to Stream Order in Geum River Watershed

  • Lee, Su-Ho;Lee, Jae-Hoon;Han, Jeong-Ho;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.43 no.4
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    • pp.503-512
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    • 2010
  • This study was conducted to evaluate fish fauna, species composition, and various guilds against stream orders along with analysis of fish community structure and diversity in Geum River watershed from 2005 to 2007. The total number of fish collected was 4,216 representing 12 families with 56 species. Zacco platypus was the most abundant fish species with 26% in relative abundance (RA). Korean endemic species were 24 species including Zacco koreanus, Microphysogobio yaluensis, Gobiobotia nakdongensis, and Iksookimia koreensis, etc. We also collected endangered fish species such as G. nakdongensis, Liobagrus obesus, and Pseudopungtungia nigra, etc., and their new distribution sites were found in the survey, providing some sites of the fish conservation and protection. Fish tolerance and trophic guilds analysis showed that the proportion of sensitive species, intermediate species, and tolerant species were 33.4%, 29.3%, and 37.3%, respectively and omnivores and insectivores were 48.1 % and 38.4%, respectively. Analysis of site-base study indicated that tolerant species and omnivore species were high in some polluted tributary streams (i.e., Gap and Miho stream) and sensitive and insectivore species were low. In the functional relations, expressed as simple linear regression equations, of stream order on fish metric attributes, showed that the number of species and the number of individuals increased as the stream order increases. This phenomenon was explained by greater availability of stable water volume, rich food, and higher physical habitat capacity. Such guild compositions and stream order characteristics of the river influenced the community structures, based on species diversity, dominance and evenness index in the study. This study may be used as important data in the future for comparisons of fish fauna and compositions before and after two weir (dam) constructions in the middle of Geum River by the government.

Occurrence and distribution characteristics of weed species in organic paddy fields

  • Hwang, Ki Seon;Jung, Sunghoon;Kim, Sung-Chul;Chung, Doug-Young;Park, Kee Woong
    • Korean Journal of Agricultural Science
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    • v.44 no.3
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    • pp.325-331
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    • 2017
  • This study was conducted to investigate the dominance and distribution of weed species in organic and conventional paddy fields. The organic paddy fields were maintained for organic farming for more than five years in Anseong, Gyeonggi province of Korea. According to the Braun-Blanquet method, 42 and 36 weed species were found in the organic paddy fields in 2015 and 2016, respectively, while 38 and 36 weed species were found in the conventional paddy fields in 2015 and 2016, respectively. As a result of two years' survey, 53 species from 24 families in the organic paddy fields were identified and classified as 32 annuals, 3 biennials and 18 perennials. In conventional paddy fields, 51 species from 24 families (30 annuals, 6 biennials, and 15 perennials) were identified. According to the classification by family, the most abundant weed species were Compositae (9 species), followed by Poaceae (8 species) and Polygonaceae (6 species) in organic paddy fields. In conventional paddy fields, Compositae (9 species) were the most abundant weed species, followed by Cruciferae (6 species), Poaceae, Polygonaceae, and Cyperaceae. This result indicates that the difference in diversity of weeds in paddy fields was influenced more by the agricultural environment than the type of cultivation. Our results could be used as a base data to control the occurrence of weed species in the paddy fields.

A variation of fish assemblage by trammel net in the coastal waters of Sagye-ri, southern Jeju Island (제주도 남부 사계리 연안에서 삼중자망으로 어획된 어류군집 변화)

  • Jun-Cheol KO;Bo-Yeon KIM;Song-Heon HAN;Min-Sun KIM;Jung-Hyun KWAK
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.60 no.2
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    • pp.114-127
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    • 2024
  • A variation of fish assemblage in the coastal waters of Sagye-ri, southern Jeju Island was determined using samples collected by trammel net from 2012 to 2022. The total fish species caught by trammel net were identified 88 species, 46 families, 12 orders, and the number of appearance and biomass were 3,479 individuals and 883.6 kg. The annual variation of species was the highest in 2013 at 46 species and the lowest in 2021 at 30 species. The seasonal variation of species was higher in summer at 67 species and lower in winter, autumn at 47 species. The annual diversity index, evenness index, and richness index were appeared 2.42-3.00, 0.69-0.78 and 5.18-7.24 at each years. The dominance index appeared highest in 2013 and the lowest in 2018. Cluster analysis based on the number of individuals of fish was classified into two groups at the dissimilarity level of 57%, and results of SIMPROF analysis revealed significant differences in community structure among the two groups. The subtropical fishes were identified a total of 42 species (47.7%) and the number of species was higher in 2013 at 25 (54.3%) species and lower in 2018 and 2021 at each 17 (54.8~56.7%) species. The dominant species of subtropical fishes were appeared rabbit fish (Siganus fuscescens), scarbreast tuskfish (Choerodon azurio), bluestriped angelfish (Chaetodontoplus septentrionalis), balloon fish (Diodon holocanthus), and flag fish (Goniistius zonatus) at study sites.

Effect of Covering the Soil with Naturally Degrading Polymer Film on the Benthic Macroinvertebrates Community Structure in Paddy Field (자연분해비닐 논토양 피복이 저서성 대형무척추동물의 군집구조에 미치는 영향)

  • Park, Jin-Young;Kwon, Soon-Jik;Nam, Hong-Sik;Kang, Chung-Kil;Park, Jong-Kyun
    • Korean journal of applied entomology
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    • v.50 no.2
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    • pp.83-96
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    • 2011
  • This study was conducted to investigate the influence of natural degrading polymer film covering in rice paddies on the benthic macroinvertebrate community structure in Dangsu-dong, Suwon, Gyeonggi-do from May 2009 to September 2009. We compared 5 treatments: golden apple snail farming (GF), natural degrading polymer film + organic farming (NOF), natural degrading polymer film + chemical farming (NCF), conventional farming (CF), and no fertilization (NF) as the control. The total number of species was highest in NOF followed by GF, NF, NCF, and CF. The total number of individuals was highest in NOF followed by NCF, CF, NF, and GF. The Dominance index (DI) ranged from 0.43 to 0.95. The highest dominance index was in GF followed by NCF, NF=CF, and NOF. The species diversity index (H') for each experimental plot ranged from 0.49 to 2.93. The average species diversity index was highest in NOF followed by NF, GF, CF, and NCF. After the natural degrading polymer film covered the paddies, the benthic macroinvertebrates tended to recover, but leeches and aquatic beetles increased. Mollusca and Annelida, which are sensitive taxa, decreased in both species and individual numbers after the soil was covered with the natural degrading polymer film. The number of species tended to recover. However, the number of individuals continued to decrease.d, especially individuals. Since then, the number of species tended to recover. However, the number of individuals decreased.

Study on the Dynamics of Fish Community in the Lake Paldang (팔당호의 어류군집 동태)

  • Son, Yeong-Mok;Song, Ho-Bok;Byeon, Hwa-Kun;Choi, Jae-Seok
    • Korean Journal of Ichthyology
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    • v.9 no.1
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    • pp.141-152
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    • 1997
  • The dynamics of fish community was investigated in the Lake Paldang from September 1995 to August 1996. The collected fishes were classified into forty two species involving in eleven families. Dominant species was Erythroculter erythropterus (relative abundance : 27.96%) and subdominant species was Lepomis macrochirus (20.69%). Also, Squalidus japonicus coreanus (19.25%), Opsariichthys bidens (4.07%), Hemibarbus labeo (3.42%), Acheilognathus yamatsutae (2.68%) and Micropterus salmoides (2.68%) were numerous. Dominant species was L. macrochirus in spring and autumn and S. japonacus coreanus in summer. E. erythropterus was subdominated in all seasons. The still-water fishes increased after construction of Paldang Dam. Ten were endemic species in Korea. Four species were exotic, and they occupied 24.75% in relative abundance. Dominance index was high at St. 2, diversity and evenness at St. 5, and richness at St. 4. In these stations, collection was made with casting net and scoop net. In the stations where collection was made with fixed shore net, dominance index was high at St. 8, diversity and evenness at St. 14, and richness at St. 7. E. erythropterus showed a stable age structure, while L. macrochirus was composed of mainly 3~4 year classes.

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Biogeography of marine bivalve mollusks of eastern Korea

  • Lutaenko, Konstantin A.;Noseworthy, Ronald G.
    • The Korean Journal of Malacology
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    • v.30 no.3
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    • pp.281-293
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    • 2014
  • The biogeography and diversity patterns of the marine bivalve molluscan fauna of the East Sea coast of South Korea are analyzed. The total species richness of the continental Korean bivalve fauna, excluding insular regions (Dok-do and Ullung-do), is 304, and from north to south the species richness of bivalves increases showing a clear gradient: Gangwon, 143 species ${\rightarrow}$ Gyeongbuk, 131 ${\rightarrow}$ Gyeongnam, 183. A zonal-geographical analysis of the entire fauna shows that the great majority are warm-water mollusks, constituting 77% (subtropical, 37%, tropical-subtropical, 30%, subtropical-boreal, 10%), The number of boreal (low-boreal, widely distributed boreal and circumboreal) species is lower, 19%, whereas boreal-arctic mollusks have only 4%. This demonstrates that the bivalve molluscan fauna of the eastern coast of Korea is subtropical, and has more affinities to the fauna of the East China Sea than to the northern East Sea. Separate analysis by provinces shows the increasing role of warm-water mollusks from north to south. While tropical-subtropical and subtropical species constitute 47% (68 species) in Gangwon, their dominance increases to 71% (93 species) in Gyeongbuk, and to 80% (148 species) in Gyeongnam. The Gyeongnam bivalve fauna is the most diverse in species composition and has the largest number of "endemics" (species known only from this province), 46%. The Gangwon fauna also contains many "endemics", up to 40%, while Gyeongbuk is an intermediate zone with low "endemicity", only at one-fifth of the regional fauna, and has the most species in common among the three provinces.

Phenological Characteristics of Rhododendron Species in Temperate Mixed Broad-leaved Forests of Arunachal Himalaya, India

  • Paul, Ashish;Khan, Mohamed Latif;Das, Ashesh Kumar
    • Journal of Forest and Environmental Science
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    • v.34 no.6
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    • pp.435-450
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    • 2018
  • Phenological events of four Rhododendron tree species (viz. R. arboreum, R. arboreum ssp. delavayi var. delavayi, R. barbatum and R. kesangiae) was monitored in temperate mixed broad-leaved forests of Arunachal Pradesh, India. Phenological events like flower bud formation, flowering, fruit setting, fruit maturing, seed dispersal, leaf bud formation, leaf flushing, and leaf shedding were recorded. Indices i.e., phenophase sequence index (PSI), active phenophasic period of the species (APS) and index of reproductive/vegetative activity (RVA) were also calculated. Present study revealed that bark consistency, growth form and leaf pattern of the studied species have showed variations among the species. Rhododendron species exhibited the phenological events overlapping with other phenophases. The peak flower bud formation was observed during the winter; R. arboreum ssp. delavayi var. delavayi start flowering from December, while the flowering in rest three species exhibited during February to April. Fruit setting occurred during summer to autumn while fruit maturation revealed peak during November. Leaf bud formation illustrated two peaks in April and May, leaf flushing exhibited peak in June, while leaf shedding peaked during October to November. Active phenophasic period of the species were found 12 months, which revealed that species engage in various phenophase activities throughout the year. Phenophase sequence index ranged between 0.8 to 0.9 (PSI ${\geq}0.6$), signifies that species have a sequential arrangement of phenophases. Index of reproductive/vegetative activity of the species exemplified >1, indicate that the reproductive phenophases were dominance over vegetative phenophases. The study have provided substantial insight on the life cycle events of Rhododendron species and ecological approaches for further scientific study with recent climate change and effective management and conservation.

Bird Diversity and Environmental Correlates in the Mulchat-oream Wetlands of the Jeju Islands, South Korea

  • Jeong, Young-Hun;Jin, Seon-Deok;Banjade, Maniram;Son, Se-Hwan;Choi, Sung-Hoon;Choi, Sung-Hwan;Oh, Hong-Shik
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.3 no.2
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    • pp.77-83
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    • 2022
  • This study was conducted from March 2018 to December 2019 to identify bird diversity and environmental correlates within the Mulchat-oream wetlands in the Jeju Islands of South Korea. A total of 255 individual belonging to 37 species were recorded form Mulchat-oream. The observation produced a species diversity of 3.14, species richness of 6.54 and species evenness of 0.88 in 2018, and in 2019, the observed species diversity was 3.02, species richness was 6.56 and species evenness was 0.84. The highly dominant species are composed of Passeriformes. The absence of diverse submerged plants, deep water depth and isolated geographical locations makes difficult for aquatic birds to prefer this area, and this has resulted in the dominance of Passeriformes. The appearance of the birds was the lowest in the winter and highest during the summer. The analysis showed that the species richness and evenness increased with an increase in temperature and precipitation. However, the number of species appearing during Mulchat-oream significantly dependent on the temperature (P<0.001, df=2). To date, there has been little research on bird diversity together with environmental factors for the Hallasan National Park. This study shows the environmental factors and seasonal patterns that affect bird population.