• Title/Summary/Keyword: Dominant Species

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Community Structure and Vertical Distribution of Macrobenthos in the Mussel Bed on the Goijeong Rocky Shore in Jinhae (진해 괴정 암반 조간대 담치대의 대형저서동물 군집구조 및 수직분포)

  • PAIK Sang-Gyu;YUN Sung Gyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.5
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    • pp.500-508
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    • 2003
  • The fauna associated with mussel (Mytilus galloprovincialis) beds and vertical distribution of macrobenthos were studied on the Goijeong rocky shore in Jinhae Bay, Korea. Sampling was conducted seasonally using a quadrate from January to October, 1998. In the first experiment, to reveal the community structure of macrobenthos in mussel bed, a total of 62 species $(10,690ind./m^2,\;3,802.1\;g/m^2)$ were identified, which included polychaetes $(32\;spp.,\;52.6\%),$ molluscs (16 spp.), crustaceans (10 spp.), and others. The density-dominant species were Pseudopolydora antennata, Nereis heterocirrata, Littorina brevicula and Balanus kondakovi. And the density of associated fauna was correlated with that of mussel (r=0.951, p=0.049). In the second experiment, to reveal the vertical distribution of macrobenthos on the rocky shore, ANOVA showed highly significant differences between the density of top 5 dominant species (Chthamalus challengeri, Littorina brevicula, Balanus kondakovi, Septifer virgatus and Granulilittorina exigua) and tidal levels (P=0.000). Vertical distribution of macrobnethos was characterized by Ghthamalus belt and Balanus-Septifer belt in the mussel bed.

Community Structure of Free-living Marine Nematodes in the Area of Agar-Producing Alga Ahnfeltia Tobuchiensis Field (Starka Strait, Peter the Great Bay, East Sea)

  • Pavlyuk, Olga;Trebukhova, Yulia
    • Ocean Science Journal
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    • v.42 no.3
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    • pp.165-170
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    • 2007
  • The structure of the nematodes communities has been studied in the sediments on two sites located outside and under the layer of Ahnfeltia tobuchiensis (Kanno and Matsubara 1932; Makijenko 1970). Bottom sediments at the stations were represented by sands with a different degree of silting. Specific structure of nematodes at the stations was significantly different under the similar environmental conditions (water depth, dissolved oxygen saturation, salinity, temperature of the bottom layer and organic carbon content inside of the sediment). Nematodes dominated (75.7 %) in meiobenthos community under the layer of A. tobuchiensis where concentration of silt particles was 12 %. Representatives of the family Comesomatidae were dominant. Low index of species diversity and high Simpson domination index were detected in this community. Under a layer of A. tobuchiensis with the thickness of 30 cm concentration of the silt particles was 5.39 %; nematodes density was low and made 32.1 % of the general density of meiobenthos. Species of the families Xyalidae and Monoposthiidae were dominant. Outside of A. tobuchiensis, field percentage of silt particles was minimal (3.1 %) and representatives of families Cyatholaimidae and Axonolaimidae dominated. The specific structure of nematodes in this type of the ground is characterized by high index of species diversity and low level of domination.

The Abundance and Damaging Period of the 'Dark grey cutworm' (Agrotis tokionis B.) (숯검은밤나방유충의 발생과 가해기에 관한 연구)

  • Kim S.S.;Boo K.S.;Oh M.H.;Sohn J.S.
    • Korean journal of applied entomology
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    • v.20 no.3 s.48
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    • pp.168-172
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    • 1981
  • This work was carried out to study field biology of Agrotis tekienis B. in Korea for two years (1979 and 1980), The species was found to be the dominant species among cutworms giving damage to young Plants in Spring with making up approximately $80\%$ or more of cutworms collected at Suweon and Jeonju from March to early June. During April and May which is the most critical period as far as plant damage by cutworms is concerned, those of A. tokionis larvae collected were at 5th and 6th instar. A. tokionis larvae enter a summer diapause from late May to early July and Agrotis ipsilon became the dominant species. It is also suggested that A. tokionis larvae be called as the 'dark grey cutworm', based upon its larval body color.

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Arthropod Community in Small Rice Fields Managed by Different Fertilization Rate and Pesticide Application in Suwon (시비량과 농약사용을 달리한 수원지역 소규모 농가 수도포장에서의 절지동물 군집)

  • 이준호;김광호;이호진
    • The Korean Journal of Ecology
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    • v.21 no.1
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    • pp.15-26
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    • 1998
  • This study was conducted to analyze arthropod community patterns in smallrice fields managed by different cultural methods [Conventional and Low Input Sustainable Agriculture(LISA)] in Suwon in 1995 and 1996. A half of nitrogen fertilizers and a quarter of pesticides were applied in the LISA field compared to in the conventional field. Total 15 orders and 43 families of arthropods were collected in two years. No differences were found in arthropod abundance and arthropod species composition between two differently practiced fields. The arthropod community was analyzed using guild categories. The arthropods were found in the order of 'pest(phytophag)>natural enemy>non-pest' in their densities. The pest species were mainly Homoptera and dominated by Delphacidae (Nilaparvata lugens Stal and Sogatella furcifera Horvath). They constituted > 80% of pest abundance. The spider was the most dominant group in the natural enemy and constituted > 90% of natural enemy abundance. Hunting spiders constituted > 60% of spider abundance and were dominated by Pirata subpiraticus Bos. et Str.(Lycosidae). Pachygnatha clerki Sundevall(Tetragnathidae), Gnathonarium dentatum Weider and Ummeliata angulituberis Oi(Erigonidae) were the dominant species in webbing spiders.

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Succession and Heterogeneity of Plant Community in Mt. Yongam, Kwangnung Experimental Forest (광릉내 용암산 식물군집의 천이와 이질성)

  • You, Young-Han;Kwang-Je Gi;Dong-Uk Han;Young-se Kwak;Joon-He Kim
    • The Korean Journal of Ecology
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    • v.18 no.1
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    • pp.89-97
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    • 1995
  • In order to study the successional trend and the heterogeneity of forest community, we investigated DBH frequency distribution of dominant tree species and the changes of several community indicies including ${\beta}-diversity\;({\beta}_t)$ along a belt transect in Mt. Yongam, Kwangnung Experimental Forest, which has been preserved for about 530 years. Quercus serrata, Carpinus laxiflora, and C. cordata were the three dominant species and their DBH frequency distribution showed a reverse J-shaped form, so these species seem to maintain by themselves. Dominancediversity curve had a lognormal distribution. d and H'for pooled quadrats were 0.13 and 1.09, respectively, but these indices within each quadiat varied with the range of 0.13 to 0.57 and 0.5 to 1.09, respectively. The value of ${\beta}_t$ along the belt transect ranged from 0.14 to 0.42. These results suggest that this forest community is in the stable climax stage but the components experience a heterogeneous microsuccession.

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The Structure Analysis of Intertidal Algal Community in Muchangpo, Western Coast of Korea (서해안 무창포의 조간대 해조 군집구조의 분석)

  • 김영환;이인규
    • Journal of Plant Biology
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    • v.28 no.2
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    • pp.149-164
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    • 1985
  • Intertidal algal community of Muchangpo in western coast of Korea was investigated qualitatively and quantitatively. Seasonal changes of algal occurrence, dominant species in cover, vertical zonation pattern and biomass were analysed. A total of sixty-four species of marine algae, one blue-green alga, three green algae, nineteen brown algae and forty-one red algae, were identified. The dominant species in cover were Sargassum thunbergii, Gelidium divaricatum and Pelvetia siliquosa throughout the year. Gloiopeltis furcata was abundant at upper and middle littoral zones and Corallina pilulifera at lower littoral zone. Classification by unweighted pair-group average method and ordination by reciprocal averaging based on the cover data indicated that, on the whole, the intertidal algal vegetation showed different patterns along tidal levels. Seasonal fluctuations of mean biomass were 57.2~92.8 g-dry/$m^2$, and the highest in summer and the lowest in spring season. Seasonal change of community structure was also discussed.

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Vertical Distribution of Seaweeds in the Rocky Shore Ecosystem in Geomundo, South Coast of Korea: Analyzing Strengths and Weaknesses Using a Survey Method (한국의 남해 거문도 암반조하대의 수심별 해조류의 분포: 조사기법에 따른 장·단점)

  • Jong Il Bai;Sung Il hwang;Sang Jo Han;Bong Jun Seong;Byeong Hyeon Jeon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.57 no.3
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    • pp.278-291
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    • 2024
  • This study performed three research methods (destructive, non-destructive, and panoramic image analysis) to determine the most useful for identifying seaweed habitat characteristics. Panoramic images are suitable for understanding the overall seaweed distribution. The composition of the main dominant seaweed species showed a significant difference between the destructive and non-destructive methods using Quadrat. The destructive method showed Rhodophyta dominance, whereas the non-destructive was showed Phaeophyta as dominant. Destructive methods are disadvantageous because they destroy natural communities in sea areas where bleaching is severe. Non-destructive methods are disadvantageous because of the difficulty in analyzing small species. Performing 10 surveys using a non-destructive method was found to explain up to 80% of the species identified by the destructive method. However, considering the difficulty of field investigation, repeating the investigation with non-destructive methods at least 6-7 times is necessary to ensure that more than 60% of the destructive methods can be interpreted. To understand the distribution of oceanic marine algae, performing both destructive and non-destructive surveys are necessary, as each has its own merits and demerits.

Analysis of Species Composition and Communities of Phytoplankton through Marine Environmental Factors in the Coastal Water of Baegyado Island during Winter (백야도 연안의 동계 해양환경 특성에 따른 식물플랑크톤의 종조성과 군집 분석)

  • Kim, Mi-Kyung;Park, Jung-Won
    • ALGAE
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    • v.19 no.3
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    • pp.247-255
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    • 2004
  • This study was to clarify the variations in a marine ecosystem through examining the species composition of phytoplankton in the coastal water of Baegyado Island during winter. Water temperature, salinity, SS, NH$_4$-N, NO$_2$-N, NO$_3$-N and SiO$_2$-Si were significantly different and in inverse proportion to the chlorophyll a and species number according to stations and water depth. The total number of species was 88, composed of 94% Bacillariophyceae, 3.4% Chrysophyceae, 2.2% Dinophyceae and 1.1% Euglenophyceae. The dominant species were Rhizosolenia setigera, Skeletonema costatum and Stephanopyxis palmeriana. The maximum of standing crops was $5,450cells{\cdot}ml^(-1)$, while the minimum was $1,700cells{\cdot}ml^(-1)$. The coastal water was influenced with two water bodies which had characteristics of low water temperature - low salinity and high water temperature - high salinity.

Disturbance and Its Role in Forest Ecosystems (삼림생태계에서의 교란과 그 역할)

  • 조도순
    • Journal of Plant Biology
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    • v.33 no.2
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    • pp.147-150
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    • 1990
  • Different species with similar niches can coexist in the same community if disturbances prevent compeptitive exclusion of competitively inferior species. Disturbances which open up gaps are common in all kind of community. Even in virgin forests without any artificial disturbance, there exist a significant proportion of trees of early successional shade-in-tolerant species in addition to the dominant late successional shade-tolerant species. In forest ecosystems, most canopy tree species including shade-tolerant ones require one or more gaps in their life-time to reach the canopy. Because of these frequent disturbances, forests can be considered of dynamic mosaics of patches of different ages and with different species composition which are in certain stages of recovery from disturbances. Disturbances temporarily increase the availability of resources such as light, water and soil nutrient for other in dividuals through the death of one or more canopy trees.

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Seasonal Variation of Species Composition of fish by Otter Trawl in the Coastal Waters off Gijang, Busan, Korea (부산 기장 연안에서 저인망으로 어획된 어류 군집의 계절 변화)

  • Hwang, Choul-Hee;Park, Yun Jeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.50 no.4
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    • pp.429-436
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    • 2017
  • The seasonal and interannual variations in fish assemblages in the coastal waters off Gijang were examined with an otter trawl from 2015 to 2016. A total of 59 fish species was collected during the study period. The dominant species were Caelorinchus multispinulosus, Clupea pallasii pallasii and Chelidonichthys spinosus. Seasonal changes in fish assemblages appeared to be distinct in the study area. The fish assemblages in summer and autumn were clearly distinguishable from those in other seasons, and the largest numbers of species and individuals were captured in winter and summer, respectively. Because fish assemblages are closely related to changes in water temperature, long-term changes in water temperature can have a significant impact on the productivity of offshore fisheries by changing fish species composition, habitat migration, and growth rate of fish.