• 제목/요약/키워드: Assemblage

검색결과 493건 처리시간 0.028초

춘양 화강암체 주변 두음리층에 산출하는 십자석-흑운모-홍주석-석류석 광물조합: 대수학적 분석 (The SBAG assemblage in the Dueumri Formation mear the Chunyang granite : Algebraic analysis)

  • 양판석;조문섭
    • 암석학회지
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    • 제4권1호
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    • pp.49-58
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    • 1995
  • 춘양 화강암체 주변의 두음리층 변성이질암내에서 십자석-흑운모-홍주석-석류석 (SBAG)광물 조합과 부광물 조합(SBA 및 SBG)이 홍주석과 십자석대에 걸쳐 흔히 산출한다. SBAG 광물 조합은 KFMASH($K_2O-FeO-MgO-Al_2O_3-SiO_2-H_2O$) 모델 계에서 자유도가 1이기 때문에 광역적으로 산출하기 힘들다. 이 SBAG (부)광물 조합의 평형 관계를 밝히기 위하여 투영법과 특이치 분해법(Singular Value Decomposition, SVD, method)을 사용하였다. SBAG 광물 조합을 가지는 단일 시료는 SVD 모델 반응식을 보이지 않으면 비-KFMASH성분에 의해 안정되었음을 나타낸다. 한편, SBAG 및 부광물 조합은 AFM-Mn 성분공간 내에서 서로 교차하기 때문에 반응 관계를 시사한다. 그러나 SVD 모델링은 이들 사이에 반응 관계를 지지하지 못한다. 그러므로, SBAG와 부광물 조합은 전암 성분이나 ${\mu}_{H20}$의 차이에 의해 두음리층에서 비교적 넓게 산출함을 알수 있다. 두음리층이 홍주석대 및 규선석대에서 십자석이 안정함을 석류석-사정석-흑운모-백운모 지압계를 사용하여 구한 변성 압력과도 일치한다.

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가막만의 빈산소 퇴적층 형성과 저서성 유공충 군집변화 연구 (The Formation of Hypoxia Sediment and Benthic Foraminiferal Change in Gamak Bay, Southern Coast of Korea)

  • 이연규;정다운;강소라;김용완;김신;정은호;이정식
    • Ocean and Polar Research
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    • 제34권1호
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    • pp.53-64
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    • 2012
  • In order to understand the relationship between the formation of hypoxia sediment by eutrophication and changes in benthic foraminiferal assemblage, micropaleontological and geochemical analyses were carried out on one sediment box core (K-1) recovered in the northern Gamak Bay, which is one of the aquacultural areas in the South Sea of Korea. In this analysis, the PON content in the sediment rapidly increased, while the C/N ratio and the C/S ratio decreased since 1977. These results indicate that eutrophication commenced in 1977 in the northern Gamak Bay, and consequently, the hypoxia sediment is 20 cm thick. Ammonia beccarii-Buccella frigida assemblage occurs before the formation of hypoxia sediment. Trochammina hadai-Buccella frigida assemblage appeared in the transitional period toward hypoxia and Trochammina hadai assemblage with a low abundance and diversity is observed in the hypoxia sediment. The agglutinated species T. hadai is regarded as a bio-indicator (opportunistic species) of the organic pollution in northern Gamak Bay.

고리 주변 해역 새우류의 종조성과 계절 변동 (Species Composition and Seasonal Variation of Shrimp Assemblage in the Coastal Waters of Kori, Korea)

  • 허성회;안용락
    • 한국수산과학회지
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    • 제32권6호
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    • pp.784-790
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    • 1999
  • 고리 주변 해역에 서식하는 새우류의 종조성과 계절 변동을 알아보기 위해 1996년 1월부터 12월까지 소형 otter trawl을 이용하여 새우류를 매월 소조기에 채집하였다. 조사기간 동안 채집된 새우는 6과 11종이 었으며, 자주새우 (Crangon affinis)가 매우 높은 점유율로 연중 우점하였다. 출현량의 계절 변동을 살펴보면, 6$\~$7월과 11월에 높은 값을 보였으며 겨울과 초가을에 낮은 간을 보였다. 출현종수는 다른 계절에 비해 겨울과 봄에 많았다. 종다양도지수는 1월$\~$3월에 높은 값을 보였고, 7$\~$8월과 11월에 낮은 값을 보였는데, 이 시기의 낮은 값은 자주새우의 극우점에 의해 초래되었다. 본 연구 해역에서 채집된 새우류는 출현 양상에 따라 주거종과 계절종으로 나눌 수 있었다.

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독도 주변해약에서 삼중자망으로 어획한 어류의 종조성 및 계절변동 (Seasonal Variation in Species Composition of Fish Collected by Trammel Net Around Dokdo, East Sea of Korea)

  • 이해원;홍병규;손명호;전영열;이동우;최영민;황강석
    • 한국수산과학회지
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    • 제43권6호
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    • pp.693-704
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    • 2010
  • Seasonal variation in species composition around Dokdo, East Sea of Korea, was investigated using trammel-net catches, from 2006 to 2009. A total of 53 fish species belonging to 23 families in 12 orders were captured; the orders Perciformes (12 families, 22 species) and Scorpaeniformes (four families, 22 species) were dominant. Between 2008 and 2009, 43 species were collected by trammel net. The number of species was highest in August 2009 (25 species) and lowest in February 2009 (11 species). The number of individuals and total biomass peaked in November 2009. Diversity indices for fish catches were highest in August 2008 (2.4368) and lowest in November 2009 (0.4253). The dominant species were Thamnaconus modestus and Sebastes schlegeli. Hierarchical clustering analysis showed five fish groups, with frequency and number of individuals similar to results of correspondence analysis (CA), which showed a closer relationship to the year term than the season term. CA showed that temperature was an important factor influencing fish species richness and abundance. Three main fish assemblage types coexisted around Dokdo: an East Sea coastal fish assemblage, a subtropical fish assemblage, and a cold water fish assemblage.

가막만의 저서다모류군집 (Benthic Polychaetous Community in Kamak Bay, Southern Coast of Korea)

  • 신현철
    • 한국해양학회지
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    • 제30권4호
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    • pp.250-261
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    • 1995
  • 본 연구는 남해안 가막만의 저서다모류군집의 분포 특성을 조사하기 위하여 1993 년 여름에 수행되었다. 다모류는 전체 저서동물중 개체수에 있어서 74.5%를 점하는 가 장 우점하는 동물군으로서 총 84종이 채집되었으며, 평균 서식밀도는 253 indiv.m/SUP -2/ 이었다. 대체로 가막만의 내해역과 의해역을 연결하는 북동쪽 수로와 남쪽 입구역 부근에서 출현 종수가 많았고 서식밀도가 높았다. 우점하는 다모류는 Tharyxsp sp.(31.9%), Lumbrineris longifolia (27.5%), Chone sp.(4.5%), Glycera chirori(4.2%) 등이었다. 조화분석 결과 가막만은 저서다모류의 종수와 서식밀도에 따 라 4개의 구역으로 나뉘어졌다. 만의 양쪽 입구에 해당되는 북동수로와 암쪽입구역은 Tharyx-Chone 군집이 형성되어 있으며, 가막만에서 저서다모류상이 가장 풍부한 해역 이었다. 반면 북서내만역과 백야도 인근해역은 저서동물의 서식이 거의 불가능할 정도 로 다모류가 빈약한 해역이다. 그리고 만의 중앙에 위치하는 해역은 Praxillella-Terebellides 군집이, 중앙의 구릉역에는 Glycera군집이 형성되어 있으 며, 종수 및 서식밀도에 있어서 만의 입구역과 북서내만역의 점이역에 해당되는 해역 이라 할 수 있다. 즉 가막만은 양 입구역만 해수교안이 불량하고, 과다한 퇴적물내 유 기물 함량, 저층수의 낮은 용존산소 농도로 인하여 빈약한 다모류 군집이 형성되어 있 다.

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Phylogeographic and Feeding Ecological Effects on the Mustelid Faunal Assemblages in Japan

  • Sato, Jun J.
    • Animal Systematics, Evolution and Diversity
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    • 제29권2호
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    • pp.99-114
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    • 2013
  • Phylogeographic and feeding ecological studies of seven terrestrial mustelid species (Carnivora, Mustelidae), the Japanese marten Martes melampus, the sable Martes zibellina, the Japanese badger Meles anakuma, the ermine or the stoat Mustela erminea, the Japanese weasel Mustela itatsi, the least weasel Mustela nivalis, and the Siberian weasel Mustela sibirica, representing four biogeographic patterns in the Japanese archipelagos (Hokkaido, Honshu-Shikoku-Kyushu, Tsushima, and Hokkaido-Honshu), were reviewed in order to clarify causes for the faunal assemblage processes of those mustelid species in Japan. Here, three main constraints were extracted as important factors on the mustelid assemblage. First, fundamental evolutionary differences maintained by niche conservatism in each ecologically diversified lineage ("evolutionary constraint") would enable the species to co-occur without any major problem (coexistence among Martes, Meles, and Mustela species). Second, "ecological constraints" would force two closely related species to be allopatric by competitive exclusion (Mu. itatsi and Mu. sibirica) or to be sympatric by resource partitions (Mu. erminea and Mu. nivalis). Third and most importantly, "geological constraints" would allow specific species to be embraced by a particular geographic region, primarily deciding which species co-occurs. The allopatric distribution of two Martes species in Japan would have been established by the strong effect of the geological separation in Tsugaru Strait. Elucidating both phylogeny and ecology of co-existing species in a community assemblage is important to know which species possess distinct lineage and which ecological traits are adapted to local environments, fulfilling the requirement of the field of conservation biology that endemism and adaptation should both be considered. The Japanese archipelagos would, therefore, provide valuable insight into the conservation for small carnivoran species.

사천바다목장해역 어류군집의 변동특성 (Seasonal variation of fish assemblage in Sacheon marine ranching, the southern coast of Korea)

  • 김영섭;최정화;김정년;오택윤;최광호;이동우;차형기
    • 수산해양기술연구
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    • 제46권4호
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    • pp.335-345
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    • 2010
  • Species composition and seasonal variation of fish assemblage in Sacheon marine ranching, Korea were examined. Sampling was seasonally made by a shrimp trawl from February 2009 to November 2009. A total of 55 species were collected. Of these, five species was dominant species comprising 51.1% of the total number of individuals. Nine species represented 57.3% of the total biomass. While total abundance (number of individuals) was high in spring, total biomass and species richness (number of species) and diversity were high in autumn. Cluster analysis, based on seasonally abundance data of the 21 most common species, showed that the species were separated into 4 different groups. Group A composed of Pholis nebulosa, Pleuronectes yokohamae, Hypodytes rubripinnis, Hexagrammos otakii, Tridentiger trigonocephalus and Paracercis sexfasciata, which were year round residents, group B Congr myriaster, Leiognathus nuchalis, and Platycephalus indicus, which were abundant in autumn, group C Sillago japonica, Pseudaesopia japonica, Zoarces gilli, Pholis fangi, and Pleuronichthys cornutus which were abundant in spring, and group D Sillago sihama, Cociella sp., Johnius grypotus, Cynoglossus joyneri, Cynoglossus robustus, and Pennahia argentata, which were abundant in summer. Principal component analysis revealed that seasonal variation in the fish assemblage was attributed to the abundance of temporal species such as conger and sand smelt fishes, which were abundant in summer, due to seasonal variation of water temperature.

해수 투입에 따른 동천 주변 환경 개선 평가를 위한 어류상 변화 및 관리 방안 (Management for Improvement in Water Quality and Change of Fish Assemblage in Urban Dong Stream with Input of Seawater)

  • 곽석남;김동명;정용현
    • 수산해양교육연구
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    • 제27권1호
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    • pp.253-261
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    • 2015
  • The chemical water quality and fish assemblage of Dong Stream to assessment of environmental improvement after discharge seawater were investigated from July to December 2013. BOD and DO were significantly different between before and after discharge seawater, while pH and SS did not significant. A total of 11 fish species, 218 individuals and 10,525.1g were collected. Dominant fish species were Mugil cephalus, Konosirus punctatus, Acanthogobius flavimanus and Leiognathus nuchalis which account for 77.5% of total individuals collected, and they were estuarian species. Peak number of species and individuals, and biomass occurred in September, whereas diversity index were highest in November. The water ecosystem of Dong Stream have been changed estuarian environment. As a result of stream assessment on water quality and ecosystem, water quality have been improved as 'III' grade. These results suggested that stream restoration policies such as drain pipes maintenance, management of pollution sources and riverbed dredging to improve environment and recover habitate of Dong Stream were need for set up and establishment of regular monitoring system.

소리도 주변 해역 새우류의 종조성과 계절변동 (Species Composition and Seasonal Change of Shrimp Assemblage in the Coastal Waters of Sorido, Korea)

  • 윤호섭;서호영;최상덕
    • 한국양식학회지
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    • 제17권1호
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    • pp.51-57
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    • 2004
  • 소리도 주변해역에서 서식하는 새우류의 종조성과 계절변동을 파악하기 위하여 2000년 6월부터 2001년 5월까지 매월 1회씩 사리기간중 간조시에 채집하였다. 조사기간 동안 채집된 새우는 6과 16종이었으며, 그라비새우, Ρ. gravieri, 꽃새우, Τ. curvirostris, 마루자주새우, C. hakodatei, 중하, Μ. joyneri등이 연중 우점하였다. 월별 출현종수는 8월, 10월, 11월에 14종으로 가장 많이 출현하였으며, 하계인 6월과 7월에 각각 8, 10종으로 가장 적은 종이 출현하였다. 종다양도 지수는 0.14∼0.82의 범위를 나타내었으며, 5∼7월에는 비교적 낮은 값을 보였는데, 이는 균등도 지수에서도 마찬가지 결과였으며, 반면 9∼12월에는 비교적 높은 종다양도 지수 값을 보였다. 본 연구 해역에서 채집된 새우류는 출현 양상에 따라 주거종과 계절종, 일시방문종으로 나눌 수 있었다.

Ground beetle (Coleoptera: Carabidae) assemblage in the urban landscape, Korea

  • Jung, Jong-Kook;Kim, Seung-Tae;Lee, Sue-Yeon;Park, Chang-Kyu;Lee, Eun-Heui;Lee, Joon-Ho
    • Journal of Ecology and Environment
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    • 제35권2호
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    • pp.79-89
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    • 2012
  • This study was conducted with the intention of clarifying the effects of land-use types on a species of ground beetle's richness, abundance, and composition; the study focused on urban landscapes. We also selected the potential bioindicators classifying land-use types; eleven sites were selected from an urban landscape in Korea. Overall, land-use types in urban landscapes did not appear to cause significant decrease in species richness or the abundance of total ground beetle assemblage. According to habitat preferences, several land-use types and distances from the forest significantly affected the species richness and abundance, while the open-habitat species were not affected by these variables. Land-use types were classified into two major groups, forest and non-forest areas, based on ground beetle assemblage; several indicators, such as $Dolichus$ $halensis$ $halensis$ and subfamily Carabinae species, were of particular consideration. In conclusion, environmental change by anthropogenic disturbance can cause different effects on ground beetle assemblages, and forest specialists can be negatively affected.