• 제목/요약/키워드: Tropical Oceanic Species

검색결과 3건 처리시간 0.016초

New records of three dinophycean genera Dinophysis, Histioneis, and Parahistioneis (Dinophysiales, Dinophyceae) from coastal waters of Jeju Island, Korea

  • Lee, Joon-Baek;Kim, Hyeung-Sin;Chung, Han-Sik
    • Journal of Ecology and Environment
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    • 제38권4호
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    • pp.599-609
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    • 2015
  • A total of 19 species of three genera Dinophysis, Histioneis, and Parahistioneis of the family Dinophysaceae are reported here from samples obtained using a 20-µm mesh net from June 2006 to December 2014 around Jeju Island including the East China Sea, and 16 of these species are new to Korean waters. A checklist of the three genera of dinoflagellates reported from coastal and oceanic Korean waters is presented. Short descriptions and synonyms are given for each species. The dinoflagellates of the family Dinophysaceae belong to mostly marine species, and include many tropical and/or subtropical species. Recently, the composition of dinoflagellate species has changed around Jeju Island as well as in Korean waters due to global warming and climate change. Tropical and subtropical dinoflagellates occur frequently in the coastal waters of Jeju Island, which reflects the ecosystem shift around the sea adjacent to Jeju Island from a temperate to a subtropical / tropical region.

열대 해역 지표종 Ornithocercus 속 와편모조의 출현 동향으로 본 한반도 온난화 (The Korean Peninsula Warming Based on Appearance Trend of Tropical Dinoflagellate Species, Genus Ornithocercus)

  • 김형신;정민민;이준백
    • 한국해양학회지:바다
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    • 제13권4호
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    • pp.303-307
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    • 2008
  • 제주도 서부해역인 차귀도 연안 해역에서 2006년 10월부터 2007년 11월 사이 5회에 걸쳐 식물 플랑크톤의 일종인 와편모조의 종 조성 변화를 조사하였으며 총 32종의 와편모조가 관찰되었다. 이들 와편모조 중 19종 즉, Amphisolenia bidentata, Ceratium gravidum, C. hexacanthum, C. platycorne, C. praelongum, C. ranipes, C. reflexum, C. geniculatum, Dissodinium elegans, D. bicorne, Ornithocercus heteroporus, O. magnificus, O. quadratus, O. splendidus, O. steinii, Protoperidinium excentricum, Pseliodinium vaubanii, Ptychodiscus noctiluca, Pyrocystis hamulus 등의 종은 한국 연안 해역에서는 매우 드물게 출현이 보고된 종이거나 미기록 종이었다. 그리고 채집된 시료에서 열대 해역 지표종인 Ornithocercus 속의 월별 단위체적당 출현량을 분석한 결과 2006년 10월, 2007년 2, 4, 9 및 11월에 각각 28, 22, 0, 3 및 $502\;cells/m^3$이었다. 또한 월별 총 와편모조류 출현량에 대한 Ornithocercus 속의 점유율은 각각 8, 3.9, 0, 0.2 및 97.9%로 2007년 11월에 최고치를 나타내었다. 이상의 연구 결과는 심각하게 진행되고 있는 지구 온난화에 발맞추어 한반도 연안 해역 역시 온난화 되어지고 있음을 부분적으로 나타내고 있다고 판단된다.

Secondary human impacts on the forest understory of Ulleung Island, South Korea, a temperate island

  • Andersen, Desiree
    • Journal of Ecology and Environment
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    • 제43권2호
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    • pp.202-211
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    • 2019
  • Oceanic islands are biologically important for their unique assemblages of species and high levels of endemism and are sensitive to environmental change because of their isolation and small species source pools. Habitat destruction caused by human landscape development is generally accepted as the main cause of extinction on islands, with exotic species invasion a secondary cause of extinction, especially on tropical islands. However, secondary impacts of human development (e.g., general degradation through resource use and exotic species introduction) are understudied on temperate islands. To determine secondary impacts of human development on the understory vegetation community, 90 field sites on Ulleung Island, South Korea, were sampled during the summer of 2016. Understory vegetation was chosen as it is a proxy for ecosystem health. Diversity and percent cover of introduced, native, and endemic species were tested against proximity to developed areas and trail usage using a model selection approach. Diversity was also tested against percent cover of three naturalized species commonly found in survey plots. The main finding was that distance to development, distance to town, and trail usage have limited negative impacts on the understory vegetation community within best-supported models predicting native and introduced cover and diversity. However, endemic species cover was significantly lower on high usage trails. While there are no apparent locally invasive plant species on the island at the time of this study, percent cover of Robinia pseudoacacia, a naturalized tree species, negatively correlated with plot diversity. These findings indicate that forests on Ulleung Island are not experiencing a noticeable invasion of understory vegetation, and conservation efforts can be best spent preventing future invasions.