• Title/Summary/Keyword: Dominant taxa

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Phytoplankton Flora and Community Structure in the Lower Nakdong River (낙동강하류의 식물플랑크톤상과 군집구조)

  • Choi, Chul-Mann;Kim, Won-Il;Lee, Jong-Sik;Jung, Goo-Bok;Lee, Jeong-Taek;Moon, Sung-Gi;Kim, Jin-Ho
    • Korean Journal of Environmental Agriculture
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    • v.26 no.2
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    • pp.159-170
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    • 2007
  • This study was focused on the investigation of the phytoplankton flora and community structure for changing of water environment at the rivers in the lower part of Nakdong river, The samples for this study were collected every month from Jan. 2004 To Dec. 2004. the 196 species belonged to 94 genera were identified during this study periods. The number of species was recorded the maximum 124 taxa in summer and the minimum 69 taxa in winter, We observed the maximum taxa (92 taxa) at the site No. 20 and the minimum taxa (55 taxa) at the site No. 8, respectively. Among the phytoplankton communities, diatoms were dominated over 40% of total phytoplankton groups. Subdominant groups were green algae (over 20% of total phytplankton groups). During this study periods, the 60 species were investigated ecologically significant species (46 cosmopolitic species, 25 pollution indicator, 21 redtide causative species, 8 dominant species, and 7 frequently occurred species). According to the cluster analysis by similarity index, the study sites could be divided into 4 groups.

Variations of Epilithic Diatom Community and an Assessment of Water Quality by DAlpo in the Middle Reaches of the Nakdong River (낙동강 중류 지역의 부착규조 군집의 변화와 유기오탁지수(DAlpo)에 의한 수질평가)

  • Choi, Jae-Sin;Kim, Mi-Kyung;Park, Jung-Won
    • Korean Journal of Ecology and Environment
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    • v.37 no.1 s.106
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    • pp.70-77
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    • 2004
  • In order to the epilithic diatom community and an assessment of water quality with diatom assemblage index of organic water pollution (DAlpo) in the middle reaches of the Nakdong River, the samples were collected from nine sampling stations on May, July, September, November, 2002 and on January 2003. A total 162 taxa was identified from this study, which were classified into 139 species and 23 varieties belonging to 33 genera. Achnanthes minutissima, Navicula subminuscula, Navicula viridula var. rostellata, Nitzschia inconspicua and Nitzschia palea indentified in every stations and examination for the whole periods. A total of 12 taxa was dominant species at any station at least one more times. In this study, average DAlpo was 30.90 ${\sim}$ 44.61 and the saprobic level was estimated ${\beta}$-mesosaprobic in the middle reaches of the Nakdong River.

Floristic composition and species richness of soil seed bank in three abandoned rice paddies along a seral gradient in Gwangneung Forest Biosphere Reserve, South Korea

  • Cho, Yong-Chan;Lee, Seon-Mi;Lee, Chang-Seok
    • Journal of Ecology and Environment
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    • v.42 no.3
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    • pp.90-102
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    • 2018
  • Background: We sought to understand the relationship between the seed bank and vegetation in abandoned rice paddies in South Korea, in order to guide management of these sites. We investigated the floristic composition and species richness of the soil seed bank and ground vegetation in former paddies along three seral gradients (wet meadow, young forest, and mature forest) in Gwangneung Forest Biosphere Reserve. Results: Seed bank samples contained 59 species, of which the dominant families were Cyperaceae, Gramineae, and Polygonaceae. Species richness and seedling density (59 taxa and 19,121 germinants from all samples) were high. Carex spp. (11, 921 germinants) were the dominant taxa. The species composition in the seed bank changed gradually as the land transitioned from wet meadow to mature forest. Sørensen's index of similarity between above- and below-ground vegetation was 29.3% for wet meadow, 10.8% for young forest, and 2.1% for mature forest. Germinant density also declined, with 10, 256 germinants for wet meadow, 6445 germinants for young forest, and 2420 germinants for mature forest. Conclusions: Changes in aboveground environment and life history traits such as amphicarpic plants, likely affect the composition of soil seed bank species. Abandoned paddy fields may be good sites for restoration of wetland forest and conservation of wetland habitat. Some intervention may be required to promote the recovery of a natural species assemblage.

Analysis on Vegetation Characteristics of Special Protected Areas in Gyeongju National Park - Focused on Pedicularis ishidoyana Koidz. & Ohwi, Millettia japonica (Siebold & Zucc.) A.Gray and Cypripedium macranthos Sw. Populations - (경주국립공원 특별보호구역의 식생 특성 분석 - 애기송이풀, 애기등, 복주머니란 개체군을 대상으로 -)

  • You, Ju-Han;Kwon, Soon-Young
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.3
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    • pp.45-62
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    • 2020
  • This study is to present the basic data for the conservation and management of natural resources of National Park by understanding the ecological characteristics of special protected areas located in Tohamsan District, Gyeongju National Park, South Korea. The numbers of vascular plants were summarized as 106 taxa including 47 families, 79 genera, 96 species, 1 subspecies, 7 varieties and 2 forms. For status by sites, there were 59, 50 and 55 taxa in A area(Pedicularis ishidoyana), B area(Millettia japonica) and C area(Cypripedium macranthos), respectively. In the dominant species, the tree layer was Quercus serrata(A area), Platycarya strobilacea and Pinus koraiensis(B area) and Fraxinus rhynchophylla(C area), the subtree layer was Carpinus cordata and Quercus serrata(A area), Pinus koraiensis and Castanea crenata(B area) and Fraxinus rhynchophylla(C area), the 1st shrub layer was Toxicodendron trichocarpum and Rhododendron schlippenbachii(A area), Lindera erythrocarpa and Styrax japonicus(B area) and Fraxinus rhynchophylla and Lindera erythrocarpa(C area), 2nd shrub layer was Styrax obassis and Lespedeza maximowiczii(A area), Lespedeza maximowiczii and Rhododendron mucronulatum(B area) and Lindera erythrocarpa(C area), the herbaceous layer was Athyrium yokoscense, Dryopteris chinensis, Dryopteris lacera and Lindera obtusiloba(A area), Athyrium yokoscense, Millettia japonica, Carex humilis Leyss. var. nana and Carex ciliato-marginata(B area) and Hydrangea macrophylla (Thunb.) Ser. subsp. serrata, Ajuga spectabilis and Oplismenus undulatifolius(C area).

Macrozoobenthic community in the deep sea soft-bottom of the KODOS 96-1 area, northeastern Pacific Ocean (북동태평양 KODOS 96-1 해역의 심해퇴적물에 분포하는 대형저서동물군집)

  • 최진우
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.1 no.2
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    • pp.73-79
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    • 1996
  • This study was conducted to investigate the faunal composition and distribution patterns of macrobenthic community in the deep sea sediments of the KODOS area, the northeastern Pacific Ocean during May 1996. Benthic animals were collected at 25 stations using a spade type box corer. Sediments were sieved through -.3 mm mesh screen. A total of 17 faunal groups in 9 phyla and 363 specimens were identified. Nematoda was the most abundant faunal group which accounted for 30.0% of total abundance. Other dominant faunal groups were foraminiferans (25.1%), harpacticoids (10.2%), xenophyophores (5.2%), and polychaetes (4.7%), Polychaeta was a typically dominant component of macrobenthic community in the study area except traditionally recognized meiofauna taxa. Mean occurrence number of faunal taxa was ca. 6 per 0.01 m$\^$2/, and mean density was estimated as 1,288 indiv./m$\^$2/. The abundance of whole fauna and that of each faunal group was highest at the surface layer of sediment, and decreased monotonously along the sediment depth; 98% of faunal abundance was found within 10 cm depth layer.

Seasonal Changes of the Phytoplankton Community at Jangjwa Lake, a Natural River Bed Lake in the Imjin River (임진강 수역의 자연 하적호 장좌못에서 식물플랑크톤 군집의 계절적 변화)

  • Yoon, Sook-Kyung;Lee, Kyung
    • Korean Journal of Ecology and Environment
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    • v.35 no.2 s.98
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    • pp.103-110
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    • 2002
  • Seasonal changes of the phytoplankton community was investigated from July 2000 to April 2001 at the river bed lake, Jangjwa Lake in the Imjin River, which appeared to be the most natural condition. A total of phytoplankton were composed of 112 taxa, belonging to 5 divisions,83 species, 10 varieties,1 variety-form, 1 form and 17 unidentified species. Of those, the green algae and the diatoms were present during the investigation periods more frequently then the other taxa. The phytoplantton standing crops varied from $2,943{\times}10^3\;cells/l$ on April 2001 to $5,742{\times}10^3\;cells/l$ on January 2001. The phytoplankton standing crops had a continuous high value over $3,000{\times}10^3\;cells/l$ during the investigated periods and showed the highest value during winter period. The major dominant species were Aulacoseira granulata, Chlamydomonas nivalis v. kobayasii, Dinobryon sertularia, Mougeotia so. and Uroglenopsis americana. Among those, Chlamydomonas nivalis v. kobayasii was a major dominant species during winter period.

Analysis on the Vegetation and Flora for the Ecological Restoration of the River (생태적 하천복원을 위한 식생 및 식물상 분석)

  • You, Ju-Han;Jung, Sung-Gwan;Lee, Cheol-Hee
    • Korean Journal of Plant Resources
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    • v.19 no.4
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    • pp.471-479
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    • 2006
  • This study was carried out to offer the natural restoration plan of river by objective analyzing the vegetation and flora around stream in Mt. Midong and to develop the materials for restoration. The flora were summarized as 95 taxa; 33 families, 84 genera, 81 species and 14 varieties. The naturalized plants were 15 taxa; Dactylis glmerata, Panicum dichotomiflorum, Rumex crispus, Chenopodium glaucum, Trifolium repens, Hibiscus trionum, Oenothera lamarckiana, Ambrosia artemisifolia var. elatior, Aster pilosus, Erigeron annuus, Erigeron canadensis, Coreopsis tinctoria, Taraxacum officinale, Bidens frondosa and Cosmos bipinnatus. The major dominant species was Phragmites japonica in all communites and semi dominant species were Salix gracilistyla, Phalaris arundinacea, Bidens frondosa and Persicaria thunbergii. To restore the river, we must consider the biddiversity, habitats and so forth, and use the plant materials like Phragmites japonica, Salix gracilistyla, Persicaria thunbergii and Veronica anagallis-aquatica.

Distribution of Fish Larvae in the Southern Coastal Waters (Yeosu, Namhae and Tongyoung) of Korea in Spring and Summer (한국 남해안(여수, 남해, 통영) 연안해역 춘·하계 어류 자치어 분포 특성)

  • Choi, Hee Chan;Yoo, Man Ho;Youn, Seok Hyun;Oh, Hyun Ju
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.759-766
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    • 2017
  • In order to identify the species composition and distribution pattern of larval fish assemblages in the southern coastal waters of Korea, monthly samples were taken using an RN80 net which was towed horizontally in three different regions (Yeosu, Namhae and Tongyoung) between May to September 2016. A total of fifty taxa were collected during the study. Among these, Engraulis japonicus, which accounted for 56.8 % of the total population, was the most dominant species, followed by Sillago japonicus, Parablennius yatabei, Gobiidae Type A, Parablennidae sp., and Omobranchus elegans as dominant taxa, that accounted for 87.5% of the total number of individuals. ANOSIM results revealed that regional groups were not separated, but seasonal groups were clearly divided with statistical significance, and these differences were caused mainly by water temperature variations identified by canonical analysis.

Species Composition of Ichthyoplankton in the Coastal Water between Yeosu and Namhae, Korea (여수와 남해 연안에 분포하는 부유성 난 및 자치어의 종조성)

  • KOH, Su-Jin;SEO, Su-Hyeon;LEE, Sung-Hoon;YU, Tae-Sik;HAN, Kyeong-Ho
    • Korean Journal of Ichthyology
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    • v.31 no.3
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    • pp.159-164
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    • 2019
  • Species composition and seasonal variation of fish eggs and larvae were investigated from 2017 to 2018. During the study period, the fish eggs were identified as belonging to 6 taxa. The dominant species of fish eggs were Engraulis japonicus, Leiognathus nuchalis, and Konosirus punctatus. These three species accounted for 96% of the total number of individuals collected. The collected larval fishes were identified into 17 taxa, 11 families, and 5 orders. The dominant species of larval fish were Engraulis japonicus, Leiognathus nuchalis, and Konosirus punctatus. These three species accounted for 70% of the total number of individuals collected. The diversity index of the larval fishes was the highest in summer (H'=1.78) and the lowest in winter (H'=1.34). The economically important species in this area were Engraulis japonicus, Konosirus punctatus, Sebastes schlegelii, Cynoglossus joyneri and Stephanolepis cirrhifer.

Insect Fauna Status of Nature Reserve Areas in Korea (국내 천연보호구역의 곤충상 현황)

  • An, Seung Lak
    • Korean Journal of Heritage: History & Science
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    • v.42 no.1
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    • pp.72-87
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    • 2009
  • This research is insect diversity analysis on the basis of survey results and bibliographies of Hongdo Island, Mts. Seoraksan, Hallasan, Daeamsan & Daeusan, Hyangnobong peak & Geonbongsan nature reserves and Dokdo Protected Natural Area among 10 designated nature reserves. The Mt. Hallasan nature reserve has 1,867 species in 22 orders and shows the highest species diversity. The species diversities of Mt. Seoraksan, Mt. Hyangnobong peak & Geonbongsan, Hongdo Island, Mt. Daeamsan & Daeusan, and Dokdo Protected Natural Area reveal 1,604 species in 19 orders, 704 species in 18 orders, 474 species in 19 orders, 468 species in 16 orders, and 114 species in 11 orders, respectively, in descending order. The order Lepidoptera shows as dominant taxa in Hongdo, Seoraksan, Hallasan, Hyangnobong peak & Geonbongsan, whereas the order Coleoptera as subdominant taxa in these areas. On the other hand, in Mt. Daeamsan & Daeusan, and Dokdo Protected Natural Area, the order Coleoptera appears as dominant taxa whereas the order Lepidoptera as subdominant taxa. The order Ephemeroptera has been shown the highest species diversity in Seoraksan which is reported to 25 species, Odonata in Hallasan to 28, Dermaptera in Seoraksan to 9, Orthoptera in Hallasan to 51, Hemiptera in Hallasan to 175, Homoptera in Seoraksan to 126, Hymenoptera in Hallasan to 183, and Diptera in Hallasan to 206. The species diversity is generally poor in Daeamsan & Daeusan, Hyangnobong peak & Geonbongsan, and Dokdo Protected Natural Area. Maybe this result is caused by the lack of various academic surveys compared to the other areas. It is needed to study systematic academic investigation on insect in the nature reserve areas in Korea, and to plan appropriate management and conservation on natural environment considering biodiversity of each nature reserve area.