• Title/Summary/Keyword: dominant period

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Ichthyofauna and Fish Community Structure in Chuncheon Reservoir (춘천호의 어류상과 군집구조)

  • Choi Jae-Seok
    • Korean Journal of Environmental Biology
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    • v.23 no.2 s.58
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    • pp.173-183
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    • 2005
  • The ichthyofauna and community structure in the Chuncheon Reservoir, Korea, were investigated from August 2003 to April 2004. The total number of fish caught from the period was 10,821 fish representing 41 species and 13 families. There were 16 Korean endemic species, including Hemibarbus mylodon, Acheilognathus yamatsutae and Odontobutis platycephala. Dominant species was Hypomesus olidus $(30.69\%) $ and subdominant species was Hemibarbus labeo $(14.70\%)$. Also, Zacco platypus $(10.57\%)$, Zacco temminckii $(9.66\%)$, Micropterus salmoides$(4.81\%)$, Rhinogobeus brunneus $(4.28\%)$ and Microphysogobio yaluensis $(3.10\%)$ were numerous. The biomass of collected fishes were Hemibarbus labeo (34.63 kg), Hypomesus olidus (19.01 kg), Cyprinus carpio (12.77 kg), Opsariichthys uncirostris amurensis (11.28 kg), Zacco platypus (8.04 kg). Among the 7 introduced fishes in Chuncheon Reservoir Carassius cuvieri, Hypophthalmichthys molitrix and Micropterus salmoides were originated from foreign countries, and others (Anguilla japonica, Hypomesus olidus, Oncorhynchus masou mason and Chaenogobius urotaenius) were introduced from other native river systems.

Vegetation Structure and Ecological Restoration Model of Quercus mongolica Community (신갈나무림의 식생구조와 생태적 복원모델)

  • Lee, Mi-Jeong;Song, Hokyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.1
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    • pp.57-65
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    • 2011
  • The composition of species for each community of Quercus by vegetation and soil survey, the community classification by TWINSPAN, the structural characteristics of communities were used and analyzed during the period of 2000~2004 for Quercus mongolica forest. And the resulting suggestions for a subsequent planting model for forest are as follows. The Quercus mongolica community had the highest importance value for Quercus mongolica followed sequentially by Acer pseudosieboldianum, Acer mono, Rhododendron schlippenbachii, Tilia amurensis, Fraxinus rhynchophylla, and Fraxinus sieboldiana. As a result of suggesting a planting modeling for the Quercus mongolica communities in the areas with the warmth index of both $60.90{\sim}79.79^{\circ}C$ and $53.96{\sim}64.82^{\circ}C$, Quercus mongolica was absolutely dominant in case of the subtree layer for the accompaniment species of distribution in the planting modeling by tree layer in the two areas depending on the warmth index, while there were distinct differences shown in case of the lower tree layer. While Acer pseudosieboldianum, Tilia amurensis, Fraxinus rhynchophylla, Sorbus alnifolia, Acer mono, etc. were appeared in the subtree layer for the areas with the warmth index of $60.90{\sim}79.79^{\circ}C$. Cornus controversa, Quercus mongolica, Fraxinus sieboldiana, etc. were many appeared in the subtree layer for the areas with the warmth index of $53.96{\sim}64.82^{\circ}C$. And, when we made ecological Quercus mongolica community, subtree layer planting is different by warmth index.

Modelling of Aerosol Vertical Distribution during a Spring Season at Gwangju, Korea

  • Shin, Sung-Kyun;Lee, Kwon-Ho
    • Asian Journal of Atmospheric Environment
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    • v.10 no.1
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    • pp.13-21
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    • 2016
  • The vertical distributions of aerosol extinction coefficient were estimated using the scaling height retrieved at Gwangju, Korea ($35.23^{\circ}N$, $126.84^{\circ}E$) during a spring season (March to May) of 2009. The aerosol scaling heights were calculated on a basis of the aerosol optical depth (AOD) and the surface visibilities. During the observation period, the scaling heights varied between 3.55 km and 0.39 km. The retrieved vertical profiles of extinction coefficient from these scaling heights were compared with extinction profile derived from the Light Detection and Ranging (LIDAR) observation. The retrieve vertical profiles of aerosol extinction coefficient were categorized into three classes according to the values of AODs and the surface visibilities: (Case I) the AODs and the surface visibilities are measured as both high, (Case II) the AODs and the surface visibilities are both lower, and (Others) the others. The averaged scaling heights for the three cases were $3.09{\pm}0.46km$, $0.82{\pm}0.27km$, and $1.46{\pm}0.57km$, respectively. For Case I, differences between the vertical profile retrieved from the scaling height and the LIDAR observation was highest. Because aerosols in Case I are considered as dust-dominant, uplifted dust above planetary boundary layer (PBL) was influenced this discrepancy. However, for the Case II and other cases, the modelled vertical aerosol extinction profiles from the scaling heights are in good agreement with the results from the LIDAR observation. Although limitation in the current modelling of vertical structure of aerosols exists for aerosol layers above PBL, the results are promising to assess aerosol profile without high-cost instruments.

Development and Succession of Marine Fouling Organisms on Artificial Substrata (인조기판 위에서 해양 부착생물의 발달 및 천이)

  • 심재형;정문섭
    • 한국해양학회지
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    • v.22 no.4
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    • pp.257-270
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    • 1987
  • Fouling communities developing in Jinhae Harbor and Masan Bay were studied by slide and panel immersion test during the period from Dec., 1982 to Nov., 1983. The total viable count of bacteria was estimated more than 1.7${\times}$ 10$\^$4/CFU/$\textrm{cm}^2$ after 15 days of immersion and 46 taxa of benthic diatoms were classified in micro-community. Progressional change of fouling communities was clearly shown and dominant diatom species are Licmophora flavellata, Navicula grevillei, and Nitzschia closterium Major macrofouling organisms are Mytilus edulis, Balanus amphitrite amphitrite, Hydroides ezoensis, and Celleporina sp. Wet weight production of macrofouling organisms exceeds 500g/100cm$\^$2/ after 5months of immersion. Regional defferences in community development are clearly shown in two study areas, and mainly due to the disparities of physicochemical stability and nutritional status of ambient water. Seasonality of larvae and the growth rate are the important factors in fouling community development. Overall process of community development is as follow : bacteria and diatoms-multicellular algae-barnacle, mussels and polychaete-sponge, anemone and ascidian.

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Comparison of Biosorption of N, P ions by Zygnema sterile and Lepocinclism textra Biomass under Irradiation Period in High Rate Algae Biomass Reactor (고율 조류 바이오매스 반응기에서 조사시간으로 본 Zygnema sterile과 Lepocinclism textra 바이오매스의 질소, 인 이온 생흡착의 비교)

  • Kong, Surk-Key
    • Journal of environmental and Sanitary engineering
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    • v.22 no.4
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    • pp.11-21
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    • 2007
  • The recent investigation indicates that the kinetic constants for anionic ions were merely the result of ion exchange between the algae cell wall surface and the anionic ion. In this study, Zygnema sterile and Lepocinclism textra, floating flagellate alga as the dominant algae strains, were cultivated using HRABR(High Rate Algae Biomass Reactor) and the cultivation conditions were 24 hrs. and 12 hrs. irradiation and it was studied how this algal biomass acts on the biosorption mechanism of anionic N and P. Results are as follows : 1. Calculating the specific chl.-a growth rate using Michaelis-Menten model, the one of 24hrs. irradiation was about 55 times higher than the one of 12 hrs. irradiation 2. Calculating the specific chl.-a growth rate using Kuo model, the one of 24 hrs. irradiation was about 2.26 times higher than the one of 12 hrs. irradiation 3. Langmuir model can apply to the biosorption mechanism of anionic N and P in HRABP. 4. Regarding the chlorophyll-a concentration as unit weight of sorbent, the ion selectivity coefficients for N and P are as follows : $(NH_3-N)+(NO_3-N)$ in 24 hrs. irradiation ; 44.984 $PO_4-P$ in 24 hrs. irradiation ; 24.237 $(NH_3-N)+(NO_3-N)$ in 12 hrs. irradiation ; 1432.851 $PO_4-P$ in 12 hrs. irradiation ; 599.076

The Growth and Nutrient Removal Efficiency of Hydrophytes at an Artificial Vegetation Island, Lake Paldang (팔당호 인공 수초재배섬에서 수생식물의 생장 및 영양염류 제거 효율)

  • Choi, Myeong-Jae;Byeon, Myeong-Seop;Park, Hae-Kyung;Jeon, Nam-Hui;Yoon, Suk-Hwan;Kong, Dong-Soo
    • Journal of Korean Society on Water Environment
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    • v.23 no.3
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    • pp.348-355
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    • 2007
  • We investigated temporal changes of composition, habitat area, growth rate and elements content of hydrophytes at the artificial vegetation island (AVI) in Kyungan Stream within Lake Paldang. We also assessed nutrient removal rate through cutting off the emergent part of hydrophytes. The kinds of hydrophytes have increased from four species (P. australis, P. japonica, T. angustifolia and the Z. latifolia) at initial stage of installation to more than 29 species for 6-year operation. P. japonica was most dominant species at the AVI in 2006. The habitat area of have increased about 2.5 times compared to the initial planting area, occupying 63% of AVI's vegetation area. The incoming species of S. fluviatilis and B. frondosa have adapted successively and expanded habitat area in the AVI. The relative growth rate of P. japonica and P. australis was highest in spring sprouting period. Their hights and weights have increased until summer, by the time they were cutting off the emergent part. They started regrowth immediately after cutting and continued to grow until September and withered away in November. The carbon contents of P. japonica and P. australis have increased during growth phase, on the contrary, the nitrogen and phosphorus contents have decreased. By cutting off and removing the emergent part (leaves and branches) of hydrophytes twice from AVI, $17.6gN/m^2/y$ of nitrogen and $1.3gP/m^2/y$ of phosphorus was removed from AVI in 2006.

Identifying dominant parameters of storm-sewer-overflows in seperate sewer system (강우시 도시배수구역의 유출특성 지배인자 분석)

  • Jung, Si Mon;Park, In Hyeok;Ha, Sung Ryong
    • Journal of Wetlands Research
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    • v.10 no.2
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    • pp.105-114
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    • 2008
  • Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Separated sewer overflows(SSO) have been considered as a major cause of water-quality deterioration of natural water-courses in the vicinity of the heavily urbanized areas. The factors defining the magnitude and occurrence of SSO are site-specific. It is important to know exact properties of pollutants contained in SSO to address water quality impacts that are caused by SSO inputs to the receiving waters. Site and event parameters found to have significant influences on urban runoff pollutant EMCs include total event rainfall, antecedent dry period, rainfall intensity. In this study, a field survey was carried out in some selected areas of Cheongju city. Literature from previous similar studies was consulted and some important factors affecting the runoff characteristics of urban drainage areas were analyzed for some selected survey points. It was found that the factors most affecting BOD are the number of dry days prior to rainfall and the intensity of the rainfall. The factor most affecting CODcr is the number of dry days prior to rainfall. The factors most affecting SS are the amount of rainfall and the number of dry days prior to rainfall. The factor most affecting TN is the amount of rainfall. The factor most affecting TP is the amount of rainfall and the number of dry days prior to rainfall.

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Ecological Studies on Yeasts in the Waters of the Yeong San River Estuary (榮山江 汽水域의 酵母에 關한 生態學的 硏究)

  • Chun, Soon-Bai
    • Korean Journal of Microbiology
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    • v.22 no.1
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    • pp.1-18
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    • 1984
  • With 156 water samples collected from 39 locations in the Yeong San River estuary during the 12month period from March 1976 to February 1977, the seasonal distribution of yeast and the distributional pattern of yeast on salinity gradient have been investigated. An overall average number of yeast ranged from 52 to 487 viable cells (c.f.u.) per 100ml water sample. The highest count of yeast was obtained in spring while the lowest value came in summer. 933 yeast and one yeast-like fungus pertaining to 14 genera and 83 species were recovered, of which Candida were 29%, Debaryomyces 17.3%, Rhodotorula Glutinis were dominant forms in all locations as well as throughout the year. The population size of total aerobic bacteria, the amount of terrestrial imputs, and some of geographical and/or climatic factor appear to reflect the seasonal distribution of yeast as well as the composition of yeast species in an estuarine environ. Average number of yeast, species diversity, and particularly the number of fermentative and pseudomycelium-producing yeasts increased with decreasing salinity whereas nitrate-utilizing yeasts showed opposite trend, suggesting that salinity gradient can be used as a feasible detector for the distributional pattern of yeast in estuarine habitat.

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The Fish Fauna and Population of Zacco koreanus in the Upper Region of the Gapyeong Stream (가평천 상류역의 어류상과 참갈겨니의 개체군 특징)

  • Choi, Jun-Kil;Jang, Chang-Ryeol;Byeon, Hwa-Kun
    • Korean Journal of Environment and Ecology
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    • v.25 no.1
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    • pp.65-70
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    • 2011
  • The fish fauna and population of Zacco koreanus in the upper region of the Gapyeong Stream was investigation from April, 2005 to August, 2009. The collected species during the survey period were 16 species belonging to 6 families. Dominant species was Z. koreanus and subdominant species was Pungtungia herzi. korea endemic species were Pseudopungtungia tenuicorpa, Coreoleuciscus splendidus, Hemibarbus mylodon, Gobiobotia brevibarba, Microphysogobio longidorsalls, Z. koreanus, Koreocobitis rotundicaudata, Iksookimia koreensis, Silorus microdorsalis, Liobagrus andersoni, Coreoperca herzi and Odontobutis platycephala, which showed a ratio of 75 % in all collected species. The species of H. mylodon was identified as natural monument, and P. tenuicorpa and G. brevibarba were endangered species. Length-weight relationship in the population of Z. koreanus was 3.44, and condition factor in the popuation was 0.004. The spawning season of Zacco koreanus was May and June.

The Characteristic of Fish Fauna by Habitat Type and Population of Zacco platypus in the Tan Stream (탄천의 서식처별 어류상과 피라미 개체군의 특징)

  • Choi, Jun-Kil;Jang, Chang-Ryeol;Byeon, Hwa-Kun
    • Korean Journal of Environment and Ecology
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    • v.25 no.1
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    • pp.71-80
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    • 2011
  • The fish fauna and characteristics of population of Zacco platypus in the 9 microhabitat at the Tan Stream was investigated from August, 2009 to April, 2010. The collected species during the survey period were 17 species belong to 7 families. Korea endemic species were Hemiculter eigenmanni and Odontobutis interrupta, which showed a ration of 11.8% in collected species. Dominant species was Z. platypus and subdominant species was Carassius auratus. Dominated species of C. auratus was at the dam-type pool, Meander-type pool, run, and rock-type pool, Pseudogobio esocinus was side channel, Rhinogobius brunneus was riffle, and Z. platypus was channel connected pool, substrate-type pool and channel unconnected pool. Length-weight relationship in the population of Z. platypus was 3.29. PCA analysis was in to the 3 groups identified. Bary-curtis cluster analysis indicated that the substrate-type pool and channel unconnected pool 65.9% showed the most similar, riffle, and dam-type 30.4% were identified as the most contrast.