• Title/Summary/Keyword: chemical diversity

Search Result 257, Processing Time 0.024 seconds

Zooplankton Community and Distributions of Copepods in Relation to Eutrophic Evaluation in Chinhae Bay (진해만 수질 환경과 동물플랑크톤 군집 및 요각류 분포 특성)

  • KANG Young-Shil;PARK Joo-Suck;LEE Sam-Seuk;KIM Hak-Gyoon;LEE Phil-Yong
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.29 no.4
    • /
    • pp.415-430
    • /
    • 1996
  • Spatio-temporal variations in zooplankton community and ropepod indicator species were investigated along with the interaction between zooplankton distribution and environmental factors in Chinhae Bay. Zooplankton samples were monthly collected at 7 stations from February to September in 1993. A NORPAC net was vertically hauled from bottom to surface, At the same station, environmental factors such as temperature, salinity and COD (chemical oxygen demand) were measured at two different water layers, surface and bottom. In August and September, salinity declined below 30.00‰ , while eutrophic parameters such as COD showed the higher concentrations than those in other months, with higher concentrations at inner bay stations. Salinities were, however, higher at bay mouth areas. These distributional patterns were believed to be caused by input and dispersion of organic matters from nearby land. Zooplankton communities were composed of 7~14. Of these, Noctiluca scintillans was predominant and occupied 90.6‰ of total zooplankton abundance. Cladocera and Copepoda were secondly abundant taxa. Among 6 to 10 copepod species appeared, Acartia omorii and A. hudsonics were most common species during the survey months except March and September. Species diversities were greater, in general, at inner bay than outer bay. The lowest diversity index was observed in February, while the highest in July. Cluster analysis could divide the study area into 2 or 4 zones for each month. Zone 1, mouth area of the bay, was characterized by the influence of offshore waters. Zone II was mixing area. Zone III and IV seemed to be affected by nearby land.

  • PDF

Long Term Variations and Environment Factors of Zooplankton Community in Lake Soyang (소양호 동물플랑크톤 군집의 장기변동과 환경요인: 2003~2014)

  • Kim, Moon Sook;Kim, Bomchul;Jun, Man-Sig
    • Korean Journal of Ecology and Environment
    • /
    • v.51 no.1
    • /
    • pp.29-39
    • /
    • 2018
  • Long-term variation of zooplankton community and species composition was studied from 2003 to 2014 in a deep reservoir, Lake Soyang, in monsoon climate region, Korea. In addition, we examined the correlation with environmental factors. Annual precipitation of watershed showed a large variation in the $705{\sim}1,779mm\;yr^{-1}$ and more than 70% of it was being concentrated from June to September. The water quality of Lake Soyang was shown a clearly seasonal variations and particularly turbid water flowing into the lake during rainy season was the most important environmental factors. Zooplankton community in Lake Soyang showed a significant difference before and after 2006. Zooplankton biomass has shown a large increase and also showed a change in the zooplankton community structure since 2006. The of zooplankton showed positive correlation with temperature and BOD, Chl. a, TP concentration. These results are considered that nutrient and organic matter contained in the turbid water influences the increase in zooplankton biomass and species composition. However, water quality was limited to account for the increase in biomass of zooplankton. For example, increase of small zooplankton density (rotifer; Keratella cochlearis, Polyarthra vulgaris) in spring which is dominated by diatoms (large size; Melosira, Synedra etc.) is considered as a bottom-up effect by the microbial loop. And increased density of crustaceans in autumn was considered a top-down effects by the relationship between predator and prey of microzooplankton and mesozooplankton. In other words the inflow of allochthonous organic matter during rainy season also affected to zooplankton food web in Lake Soyang. In conclusion, biomass, diversity and long-term variations of zooplankton in Lake Soyang were determined by physico-chemical factors but also it is considered that biological interactions is important.

RAPD Analysis for the Evaluation of Genetic Diversity Among the Fusarium Species from Various Sources (각종 작물로부터 분리한 Fusarium속 균의 RAPD 기법을 이용한 유전분석)

  • Choi, Hei-Sun;Kim, Kyong-Soo;Kim, Myong-Jo;Shim, Jae-Ouk;Kim, Byong-Sup;Lee, Min-Woong;Lee, Youn-Su
    • The Korean Journal of Mycology
    • /
    • v.25 no.3 s.82
    • /
    • pp.202-208
    • /
    • 1997
  • In this study, we evaluated the use of RAPD method to discriminate among strains of Fusarium species including F. oxysporum and f. sp. of F. oxysporum. As a result of the amplication, fifteen primers showed total 180 bands ranging from 0.2 to 3 Kb. Among those 180 bands, 126 polymorphic bands were used for bionominal matrix code (0, 1), and UPGMA dendrogram analysis. Fusarium oxysporum isolate 355 showed high similarity with F. oxysporum isolate 358 at 0.9603. Fusarium roseum isolate 87 and F. oxysporum isolate 358, F. o. f. sp. lycopersici isolate 69 and F. o. f. sp. melongena 68 showed low similarity of 0.3809. Fusarium oxysporum isolate 361 and F. o. f. sp. raphani isolate 218 showed similarity of 0.8730, F. oxysoprum isolate 354 and unidentified Fusarium sp. isolate 228 showed similarity matrix of 0.7936, and F. roseum isolate 87 and F. o. f. sp. raphani isolate 57 showed similarity matrix of 0.5873.

  • PDF

Zooplankton Community Dynamic in Lentic Freshwater Ecosystems in the Nakdong River Basin (낙동강 유역권 내 정수생태계의 동물플랑크톤 군집 동태)

  • Kim, Seong-Ki;Hong, Dong-gyun;Kang, MeeA;Lee, Kyung-Lak;Lee, Hak Young;Joo, Gea-Jae;Choi, Jong-Yun
    • Korean Journal of Environment and Ecology
    • /
    • v.29 no.3
    • /
    • pp.410-420
    • /
    • 2015
  • In order to estimate the influence of environmental factors on zooplankton communities in lentic freshwater ecosystems, 20 reservoirs and wetlands were monitored by season in 2013. A total of 109 species of zooplankton were identified during the study period. Zooplankton assemblage showed a different distribution in its density and diversity in accordance with the seasons. In particular, the density of zooplankton (98 species and 603ind. L-1) was the most in autumn when compared to the other seasons. In order to effectively analyze zooplankton distribution that are affected by various environmental factors, a Self-Organizing Map (SOM) was used, which extracts information through competitive and adaptive properties. A total of 11 variables (8 environment factors and 3 groups of zooplankton) were patterned on to the SOM. Based on a U-matrix, four clusters were identified from the model. Among zooplankton communities, rotifer displayed a positive relationship with water temperature, and cladocerans and copepod were positively related to conductivity, chlorophyll a, and nutrient factor (i. e. TN and TP). In contrast, high dissolved oxygen appeared to have a negative effect on zooplankton distribution. Consequently, the SOM results depicted a clear pattern of zooplankton density clusters partitioned by environmental factors, which play a key role in determining the seasonal distribution of zooplankton groups in lentic freshwater ecosystem.

Mineralization and Characterization of Boseung Kaolin in Gaya Area (가야 지역 보성 고령토의 광화작용 및 광물 특성)

  • Noh, Jin-Hwan
    • Journal of the Mineralogical Society of Korea
    • /
    • v.21 no.4
    • /
    • pp.397-413
    • /
    • 2008
  • In Gaya area, the Boseong kaolin deposits exhibit locally unusual occurrences such as downward enrichment of kaoin minerals, characteristic hydrothermal alterations (illite and stilbite), and phase relations among kaolin minerals in addition to the extensive weathering of anorthositic country rocks. This indicates that the kaolin deposits seem to be genetically formed as a mixed hydrothermal and residual model. The kaolin ores can be divided into five types on the basis of differences in occurrence, mineral composition and characters. These consist of two types of high-grade ores ranging above 80% in grade and low-grade ores as low as less than 80% including feldspar residuals or the peculiar impurity phase of illite-vermiculite-stilbite. Halloysite and kaolinite are mostly coexisted in the Boseong kaolin, and these kaolin minerals exhibit diverse appearances in crystallinity and morphology. Such a diversity in mineral phase and crystallinity seems to be originated from the complexity in genesis. In addition to these diverse characters of the kaolin, its applied-mineralogical characteristics such as chemical composition, thermal properties, whiteness, viscosity, and etc. made it disadvantageous in terms of ore quality.

Environmental Factors and Growth Properties of Sasa borealis (Hack.) Makino Community and Effect its Distribution on the Development of Lower Vegetation in Jirisan National Park (지리산국립공원 조릿대의 입지환경 및 생장특성 분석과 하층식생에 미치는 영향)

  • Park, Seok-Gon;Yi, Myung-Hoon;Yoon, Jung-Won;Sin, Hyun-Tak
    • Korean Journal of Environment and Ecology
    • /
    • v.26 no.1
    • /
    • pp.82-90
    • /
    • 2012
  • In this study, we investigated the environmental factors and growth characteristics of Sasa borealis community inside a temperate deciduous forest and reviewed its effect on the lower vegetation and natural regeneration. The S. borealis community in the Jungsan-ri region of Jirisan National Park was chosen as the study area, and the vegetation and the environmental factors were investigated. The dominance value, height and foliage layer thickness were investigated as the growth characteristics of S. borealis in the area. As the environmental factors, we investigated the photosynthesis photon flux density (PPFD) of the shrub and ground layers as well as the chemical characteristics of the soil. Additionally, we investigated the flora on the ground layer of the area as well as the number and height of woody plants. The result showed that the height and foliage layer thickness of the S. borealis was closely related to the light conditions but the distribution was not determined simply by the effect of the environment or vegetation of the particular area. This may be deeply related with the unique survival strategy of S. borealis, a vegetably propagated plant, that it can extensively distributed on a heterogeneous resources environment in a forest as multiple culm are interconnected with each other through the rhizomes. The dense dominance and great height of S. borealis reduced the plant species diversity in the ground layer by decreasing the PPFD on the ground surface.

Application Possibility of Naphthoquinone Derivative Nq 4-6 for Mitigation of Winter Diatom Bloom (겨울철 규조류 대발생 제어를 위한 Naphthoquinone 유도체 Nq 4-6의 적용 가능성)

  • Byun, Jung-Hwan;Joo, Jae-Hyoung;Kim, Baik-Ho;Han, Myung-Soo
    • Ecology and Resilient Infrastructure
    • /
    • v.2 no.3
    • /
    • pp.224-236
    • /
    • 2015
  • We conducted the algicidal activity screening tests using 10 L microcosm to investigate the possibility of the field application of naphthoquinone derivative Nq 4-6 compound as an algicide. We determined its application range to assess its algicidal effects on the phytoplankton and to evaluate the response of the planktonic community and the water environment to this chemical. From results of the microcosm experiments, Nq 4-6 compound showed high algicidal activity on the centric diatoms such as Stephanodiscus hantzschii and Cyclotella meneghiniana, but it had no effect on other phytoplankton. The abundance of S. hantzschii continuously increased in the control, but its cell density decreased 1 day after the Nq 4-6 treatment. In particular, Nq 4-6 showed algicidal activity of 94.4% against S. hantzschii 7 days after the treatment. The dominance index of phytoplankton community was lower in the treatment than in the control. The diversity index, richness index and evenness index of phytoplankton community was higher in the treatment. Environmental factors and biological factors did not show specific changes after the Nq 4-6 compound treatment. Therefore, the results of this study demonstrates that Nq 4-6 is an effective agent for the control of S. hantzschii blooms, and that the microcosm tests play a crucial role when assessing field application.

Prevalence of Multi-drug Resistant Bacteria Belonging to Gram Negative Enterobacteriaceae Isolated from a Domestic Stream (국내 하천에서 분리된 그람 음성 Enterobacteriacaea의 항생제 다제내성)

  • Jang, Yejin;Song, Ki-Bong;Chung, In-Young;Kim, Hyuk;Seok, Kwang-Seol;Go, Eun Byeul;Kim, Byeori;Yoo, Yong-Jae;Rhee, Ok-Jae;Chae, Jong-Chan
    • Microbiology and Biotechnology Letters
    • /
    • v.43 no.4
    • /
    • pp.396-400
    • /
    • 2015
  • Enterobacteriaceae is one of the major families responsible for public health threats. Due to the emergence of pathogens with antibiotic resistance, great concern has been raised regarding the prevalence of antibiotic resistant bacteria in natural environments. Therefore, the diversity of Gram negative Enterobacteriaceae was investigated in water samples collected from five streams in Korea using the cultivation method. Profiling of multi-drug resistance was conducted with isolates via disk diffusion assay. The results indicated that the Gram negative Enterobacteriaceae consisted of the following genus; Citrobacter, Enterobacter, Escherichia, Klebsiella, Kluyvera, Pantoea, Plesiomonas, Raoultella, Shigella and Enterobacter. These latter strains represented 49% of identified isolates. In addition, 78.3% of the identified genus exhibited resistance against more than seven out of thirteen tested antibiotics, suggesting a high prevalence of multi-drug resistant bacteria in natural environments.

Effect of Environmental Variables on the Inter- and Subtidal Macrobenthic Communities in the Iwon Dike Area (이원방조제 주변의 조간대 및 조하대 대형저서동물의 군집과 환경요인과의 관계)

  • LEE Jae-Hac;YU Ok Hwan;LEE Hyung-Gon;PARK Ja-Yang
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.37 no.4
    • /
    • pp.295-306
    • /
    • 2004
  • Spatial patterns in the macrobenthic community structure in the inter- and subtidal zones in front of the Iwon Dike and environmental variables were examined in August 2001, In total, 156 macrobenthic species(123 intertidal species and 90 subtidal species) were recorded during this study, predominately polychaetes $(40{\%})$, bivalves $(22{\%})$, and crustaceans $(22{\%})$. Polychaetes made up less than $40{\%}$ of the intertidal communitr, but more than $50{\%}$ of the subtidal community. The mean density during this study was $1,456ind./m^{2}.$ Multivariate analysis (multidimensional scaling) revealed significant differences in community structure among four regions: near the Iwon dike (B1), the high and middle intertidal zone (B2), low intertidal zone (Al), and subtidal zone (A2). The number of species, total density, and diversity (H') varied significantly among the four regions. The distribution of macrobenthic community was affected by environmental variables, such as ${\%}$ silt/clay content, total sulfide, lose of ignition, and chemical oxygen demand. These environmental variables were negatively correlated with the dominant species (Nephtys polybranchia, Umbonium thomasi, and Scoloplos armiger) in the intertidal area, but positively correlated with the dominant species (Lumbrineris cruzensis, Notomastus latericeus, and Moerella sp.) in the subtidal area. Environmental variables $({\%}\;silt/clay content and total sulfide)$ were positively correlated with the dominant species (Heteromastus filiformis) in region Bl, but negatively correlated with the dominant species (Umbonium thomasi and Scoloplos koreanus) in region B2. Amphipods Urothoe spp. and Monoculodes koreanus were the dominant species in region Al. Umbonium thomasi, the dominant species in region B2, was not found in regions Bl or Al. We suggest that the inter-specific competition for territory and exposure to seawater may be important factors controlling the macrobenthic community structure in the inter- and subtidal zones in front of the Iwon Dike.

The Association of Auditive and Visual Meanings in (영화 <이미테이션 게임>에 나타난 청각적·시각적 의미의 연합)

  • Ahn, Soo Hwan
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.7
    • /
    • pp.83-92
    • /
    • 2021
  • The goal of this paper is to explore the relationship between visual and auditive meanings of the film "The Imitation Game"(2013) which is directed by Morten Tyldum, and with music composed by Alexandre Desplat. The author accepted Zwikowski's idea of analyzing how film music and visual information created a chemical and meaningful signal for the audience. Lawrence Zbikowski has used Conceptual Integration Networks (CIN), devised by Golles Fauconnier and Mark Turner, to analyze latent meanings which was produced by the association of visual and auditive meanings. Therefore, The author applied the CIN analyzing methodology to the research combination of music and imagery in "The Imitaion Game." Desplat, the composer, has used aeolian instead of tonality to represent the main character. The aeolian melodic line was changed to create a similar atmosphere of imagery and narratives. The irregular time and minor chord was associated with unstable emotion and familiar intervals, while the major chord was associated with stable feelings. Desplat also applied instrumental diversity and extreme changes of dynamic to create positive or negative cognition. The author, therefore, found how the meanings of auditive materials and visual information combined and emphasized encoded messages in the film.