• Title/Summary/Keyword: Dominant Species

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Solubilities and Major Species of Selenium and Technetium in the KURT Groundwater Conditions (KURT 지하수 조건에서 셀레늄과 테크네튬의 용해도 및 주요 화학종)

  • Kim, Seung-Soo;Min, Je-Ho;Baik, Min-Hoon;Kim, Gye-Nam
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.10 no.1
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    • pp.13-19
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    • 2012
  • The long-lived fission products $^{79}Se$ and $^{99}Tc$ have been considered as the major concern nuclides for the disposal of radioactive waste because of their high solubilities and the existence of anionic species in natural water. In this study, the solubilities of $FeSe_2(s)$ and $TcO_2(s)$, known as respective Solubility Limiting Solid Phase (SLSP) of selenium and technetium, were measured in the KURT (KAERI Underground Research Tunnel) groundwater under various pH and redox conditions. And their solubilities and major species were also calculated using geochemical codes under conditions similar to experimental solutions. Experimental results and calculation for $FeSe_2$ show that the solubility of selenium was found to be below $1{\times}10^{-6}mol/L$ under the condition of pH 8~9.5 and Eh=-0.3~-0.4 V while the dominant species was identified as $HSe^-$. For $TcO_2$, the solubility of technetium was found to be $5{\times}10^{-8}{\sim}1{\times}10^{-9}mol/L$ in the solutions of pH 6~9.5 and Eh<-0.1 V, while the dominant species was $TcO(OH)_2$. However, when the Eh of the solution is -0.35 V, $TcO(OH)_3^-$ and $TcO_4^-$ are calculated as the dominant species at pH 10.5~12 and pH>12, respectively.

The Survey of Weed Population Distribution in Kyonggi Area (최근(最近)의 경기지역(京畿地域) 논 잡초분포(雜草分布) 조사(調査))

  • Kim, H.D.;Kim, Y.H.;Ju, Y.C.;Sung, M.S.;Choi, Y.J.;Ree, D.W.
    • Korean Journal of Weed Science
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    • v.12 no.1
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    • pp.46-51
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    • 1992
  • The survey of weed population in paddy field was carried out to invegstigate the weed group on 340 fields in Kyonggi Area in 1991. The weed species observed include 4 species of grasses, 7 species of sedges, and 14 species of broadleaf weeds, and the ratio of annual weed vs perennial weed was 25 : 75. Major dominant weed species were Eleocharis kuroguwai, Sagitaria trifolia, Echinochloa crusgalli and Cyperus serotinus. The dominant weed species in South Plain Region were Echinochloa crusgalli, Eleocharis kuroguwai, Sagitariu trifolia, Cyperus strotinus, in West Coast Region were Eleocharis kuroguwai, Sagitaria trifolia, Echinochloa crusgalli, Cyperus serotinus, in East Interior Region were Eleocharis kuroguwai, Sagitaria trifolia, Echinochloa crusgalli, Cyperus difformis and were Sagitaria trifolia, Eleocharis kuroguwai, Echinochloa crusgalli and Monochoria vaginalis in North Region. The dominant weed species in Normal and Poorly drained soil were Eleocharis kuroguwdi, Sagitaria trifolia, Echinochloa crusgalli and Cyperus serotinus and were Scirpus maritinus, Cyperus serotinus, Echinochlod crusgalli and Myriophyllum verticillatum in Saline Soil. More and many weeds were growing in single cropped field than double cropped field.

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Population density of chigger mites, the vector of tsutsugamushi disease in Chollanam-do, Korea (전라남도에서 쯔쯔가무시병 매개체인 털진드기의 개체군 밀도에 관한 조사)

  • 송현제;김개환
    • Parasites, Hosts and Diseases
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    • v.34 no.1
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    • pp.27-34
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    • 1996
  • The geographical distribution and population density of rodents and chigger mites at six localities of Chollanam-do were investigated from October to December in 1993. Among total 142 field rodents collected by the modified Chemin wooden traps, 131 rodents were Aponemw usrari,us (92.3%) and 11 were Crocidurc losiurc (7.7%). Out of 142 field rodents, 92 were parasitized by chiggers, showing 69.0% of the infestation rate and 74.2 of the chiggor index. Infestation rate and chigger index of A. omfernrius and C. lusiurc were 73.3%, 80.4 and 18.2%, 0.5, respectively. From the trapped field rodents, 10,532 chiggers were collected and identified with 11 species of 4 genera. Leptotrombidium pcLLinun. the vector 3pecies of tsutsugamushi disease, was the dominant species, showing 8,038 chi99ers (76.31%). L. scutellnre was the second dominant species showing 1,359 chiggers (12.9%). The distribution of chigger mites was clearly localized by the species, showing the different dominant species according to localities. The predominant species was 1. scutellare (100%) in Changhung-gun, 1. scutellcre (41.5%) in Posong-gun, 1. pnllidum (88.8%) in Hwasun- gun, 1. pnLlidunl (59.2%) in Koksong-gun, 1. zetum (77.3%) in Hampyong-gun, and 1. pclpcle (63.4%) in Tamyang-gun. Regarding to the geographical distribution of chigger population density, the infestation rate and chigger index was most high in Hwasun-gun as 62.4% and 216.2 respectively, and next high in Koksong-gun as 22.4% and 77.7%, respectively.

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Species Diversity of Chironomid Midge and Evaluation on Removal Capacity of Organic Matter Using a Dominant Species, Chironomus nipponensis in Agroecosystem (농업생태계 깔따구 유충의 다양성 및 우점종 닙폰깔따구를 이용한 유기물 분해능 평가)

  • Sim, Ha-Sik;Park, Byoung-Do;Lee, Young-Bo;Choi, Young-Chol;Kim, Jong-Gil;Park, Hae-Chul
    • Korean Journal of Environmental Biology
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    • v.27 no.1
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    • pp.31-39
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    • 2009
  • To recognize the species composition and community of chironomid midge in agroecosystem and evaluate removal capacity of organic matter using the dominant species among them. Chironomid midge and invertebrate cohabitants were quantitatively collected at 78 representative stations of five habitat types (in arable land during 2004$\sim$2006) A, paddy fields of the large scale arable land; B, paddy fields of the environmental friendly arable land; C, influent of domestic waste water; D, influent of waste water by livestock; E, the irrigation ditch of paddy area. The total sixteen species of chironomid midges at arable land were presented. And also chironomid midges were recognized by five habitat types: eleven species in D, eight in A, seven in E, six in B, and two in C. We confirmed dominant species in each habitat types as followings: Chironomus nipponensis in A, C, and D; Cricotopus sylvestris in E; Tanytarsus seosanensis in B. Water quality and community index were high in E, but low in A, B, C, and D. Comparing with non-treatment, removal activities of organic matter in bottom by C. nipponensis were increased 18% in 90 individuals treatment.

The Physiological and Ecological Comparisons between Warm (Pleuromamma sp.) and Cold Water Copepod Species (Neocalanus plumchrus) in the Northwestern Pacific Ocean Using Lipid Contents and Compositions (북서태평양에서 난수성(Pleuromamma sp.)과 냉수성(Neocalanus plumchrus) 요각류의 지방 함량 및 구성 분석을 통한 생리/생태 비교)

  • Ko, Ah-Ra;Ju, Se-Jong;Lee, Chang-Rae
    • Ocean and Polar Research
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    • v.31 no.1
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    • pp.121-131
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    • 2009
  • In an effort to better understand the physiological and ecological differences between warm and cold water copepod species in Korean waters using lipid contents and compositions, two species of copepods (Pleuromamma sp. as a warm water species and Neocalanus plumchrus as a cold water species) were collected from the Northwest Pacific and East Sea/Sea of Japan, respectively. The cold water species showed two fold higher lipid contents than the warm water species (11% vs. 5% of dry weight). Wax esters, known as one of the major storage lipid classes, were found to be the dominant lipid class (accounting for 64% of total lipids) in the cold water species, whereas, in the warm water species, phospholipids, which are known as membrane components, were the dominant lipid class (accounting for 43% of total lipids),with a trace amount of the storage lipids as a form of triacylglycerols (${\leq}1%$ of total lipids). With regard to the fatty acid compositions, saturated fatty acids (SAFA), especially 16:0 (about 30% of total fatty acids), were most abundant in the warm water species, whereas the polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA : 20:5(n-3)) (${\geq}16%$ of total fatty acids), were most abundant in the cold water species. Among the neutral fraction of lipids, phytol, originating from the side chain of chlorophyll and indicative of active feeding on phytoplankton, was detected only in the warm water species. Significant quantities of fatty alcohols were detected in cold water species, particularly long-chain monounsaturated fatty alcohols (i.e. 20:1(n-9) and 22:1(n-11)), which are well known to abound in cold water herbivorous copepods. However, only trace amounts of short-chain fatty alcohols were detected in the warm water species. Twelve different kinds of sterols were detected in these copepod species, with cholest-5-en-$3{\beta}$-ol (cholesterol) and cholesta-5, 24-dien-$3{\beta}$-ol (desmosterol) dominating in cold and warm water species, respectively. In addition, for the warm water species (Pleuromamma sp.), we assessed the latitudinal gradients of lipid contents and compositions using samples from three different latitudinal regions (Philippine EEZ, Japan EEZ, and the East China Sea). Although no latitudinal gradients of lipid contents were detected, the lipid compositions, particularly dietary fatty acid markers, varied significantly with the latitude. The findings of this study confirm that the distribution of lipid contents and compositions in copepods may not only indicate their nutritional condition and diet history, but may also provide insights into their living strategies under different environmental conditions (i.e., water temperature, food availability).

Spatial-temporal distribution of carabid beetles in wetlands

  • Do, Yu-No;Jo, Hyun-Bin;Kang, Ji-Hoon;Joo, Gea-Jae
    • Journal of Ecology and Environment
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    • v.35 no.1
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    • pp.51-58
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    • 2012
  • In this study, we investigated carabid beetles residing in the wetlands to understand their ecological adaptation and strategy selection associated with restricted resources and habitat limitation. The species richness, abundance, seasonal activity, and spatial distribution of the carabid beetles between the Mujechi Wetlands (wetland sites) and Mt. Jeongjok (mountain sites) have been compared. A total of 1,733 individual beetles from 30 species were collected and classified at the studied sites. The wetland sites were identified as having lower species richness and abundance for carabid beetles when compared with the adjacent mountain sites, whereas these beetles were observed to be dominant in the wetland sites than in the adjacent mountain sites. Calosoma inquisitor cyanescens, Carabus sternbergi sternbergi, and Carabus jankowskii jankowskii species were dominant in both the wetland and mountain sites. These species showed significantly different seasonal activity patterns in the wetland sites relative to the mountain sites. Although the three listed carabid species were observed to be widely distributed throughout the wetland sites, they still showed preference for drier sites, which clearly shows a distinction in their habitats. The results of the spatial-temporal distribution of carabid beetles in the wetland sites reflect their special strategies regarding space and time partitioning for maintaining their population. The distribution patterns of carabid beetles in the wetland sites also showed the desiccation gradient and environmental changes prevalent in wetlands. Ecological surveys, which use carabid beetles in the wetlands, can then be performed when restoring wetlands and for establishing management practices for improving the habitat quality.

Seasonal Fluctuations and Species Composition of Fish Collected by Long-bag Stow Net in Nang-island, Yeosu (여수 낭도 연안에서 낭장망에 어획된 어류의 종조성 및 계절변동)

  • Yu, Tae-Sik;Youn, Byoung-Il;Kim, Joon;Han, Kyeong-Ho
    • Korean Journal of Ichthyology
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    • v.32 no.2
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    • pp.91-96
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    • 2020
  • Seasonal fluctuation in abundance and species composition of fish in coastal waters off Nang island were investigated using seasonal samples collected by long-bag stow net in 2017. A total 10,208 fish were sampled and classified into 37 species, 26 families, and 9 orders. The dominant species were Engraulis japonicus (4,886 individuals, 47.9%), Pennahia argentata (842 individuals, 8.2%), and Ilisha elongata (369 individuals, 3.6%). The diversity index was the highest in May (H'=3.23) and the lowest in November (H'=1.24). The dominance index was the highest in November (D=78.7%) and the lowest in May (D=22.4%).

Analysis of the Ecological Characteristics of Vegetation in the Area Adjacent to Sasang Industrial Complex in Pusan Metropolitan City (사상공단 주변 식생의 생태적 특성 분석)

  • 박승범;김석규;남정칠;김승환;강영조;이기철
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.1
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    • pp.75-86
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    • 2002
  • This study was conducted to analyze the change of soil characteristics effect on the condition of urban forest in Sasang parti located near Sasang Industrial Complex. The results of this study are as follows; 1. Soil hardness is increasing from the area of forest, to the entrance, to facilities in that order. Soil acidity pH4.19∼4.23 in Sasang park indicated a high acidity condition. High levers of K, Na, Mg, Ca are shown in the areas composed of high soil hardness. 2. Pinus thunbergii in the overstory tree layer, Alnus japonica in the understory tree layer, and Rhus sylvestris in the shurb layer are shown respectively as dominant species based on the ground survey and the compution of important value. Pinus thunbergii is decreasing, while Alnus japonica and increasing. 3. Oplismenus undulatifolius which has a strong tolerance for air pollution, is shown as a dominant species of herbaceous plants in Sasang park. There are 10 species of Harbaceous in Sasang park compared to 20 species in Molundae park. This shows that deversity in herbaceous plants are imported by air pollution. 4. Species diversity indices of Sasang park is 0.8738∼0.9700 compared to 1.0817∼ 1.233 in Molundae park is due to the good condition of soil environment in addition to air pollution effects. 5. The vitality of Pinus thunbergii is 16.41∼20.42ER in Sasang park, and 12.42∼ 16.81ER, in Molundae park. This shows that tree vitality are impacted by soil characteristics. The regression analysis between tree vitality and soil environment shows the effects of is soil hardness, soil moisture, soil acidity, K, Na, Mg, Ca.

Aquatic Ecosystem Health Assessment in Middle Reach of Suyoung River using Characteristics of Benthic Macroinvertebrate and Fish Fauna (수질, 저서성 대형무척추동물 및 어류의 생태특성을 이용한 수영강 중류 수생태 건강성 평가)

  • Jeon, Dae-Young;Lee, So-Lim;Son, Jung-won;Cha, Young-Uk;Kwon, Ki-Won;Yoo, Pyung-Jong
    • Journal of Korean Society on Water Environment
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    • v.26 no.6
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    • pp.934-942
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    • 2010
  • Bentic macroinvertebrate and fish fauna were investigated from September 2008 to October 2009 in the middle reach of the Suyoung river in Busan. During the survey period benthic macroinvertebrates were collected total 35 species at the three sites (Hanmul-gyo, Dongcheon-gyo, Seokdae Jct.) of Suyoung river. At that sites, species diversity index was 1.9, 1.5, 1.6, dominance index was 0.75, 0.81, 0.86 and Korean Saprobic Index (KSI) was 1.8(B), 4.4(D), 4.4(D) on average, respectively. Dominant species was Caenis Kua, Chironomidae sp., at Hanmul-gyo site and Limnodrilus gotoi, Chironomidae sp., at Dongcheon-gyo and Seokdae Jct. sites. Fish fauna was also investigated at the two sites (Hanmul-gyo and Seokdae Jct.) of Suyoung river. Total caught fishes were 10 species 32 individuals in the first survey and 6 species 26 individuals in the second survey. Dominant species was Carassius auratus in the both surveys. Index of Biological Integrity (IBI) value was C grade at the Hanmul-gyo and D grade at the Seokdae Jct.

The Mycoflora of Higher Fungi in Mt. Paekdu and Adjacent Areas (I) (백두산(白頭山)의 고등균류상(高等菌類相)에 관(關)한 연구(硏究)(I))

  • Park, Seong-Sick;Cho, Duck-Hyun
    • The Korean Journal of Mycology
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    • v.20 no.1
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    • pp.11-28
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    • 1992
  • Some 420 species of higher fungi were collected from the Mt. Paekdu, Songwha river and their adjacent areas from 28th July to 12th of August, 1991 and identified to 2 subdivisions, 4 classes, 2 subclasses, 12 orders, 51 families, 141 genera and 336 species. The dominant species were Clitocybe gibba, C. clavipes, ystoderma amianthinum, Hygrocybe flavescens, H. miniata, Russula cyanoxantha, R. metica, Lactarius lignyotus, L. torminosus and Phellinus igniarius. The species found in Mt. Paekdu were newly described; Amanita muscaria var. regaris, Volvariella species var. speciosa, Cortinarius alboviolaceus, C. violaceus, Inocybe geolilacina, I. hirtella var. hirtella, Boletinus paluster, Crepidotus badiofloccosus, Lactarius circellatus var. circellatus, L. controversus and L. cilicioides.

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