Phytoplankton populations were examined at three sites in Lake Cheongpyeong, South Korea from March 2008 to December 2016, including measurement of phytoplankton communities and their dominant species, abundance and environmental factors. The annual average ranges of water temperature, dissolved oxygen and conductivity were 15.2-18.8℃ , 10.3-12.2 mg/L, 86-140 μS/cm, respectively, with similar values at all studied sites. The highest phytoplankton cell density was observed in spring and fall, and it subsequently decreased rapidly during heavy rainfall. Diatoms were dominant in spring (mainly Stephanodiscus hantzschii, Asterionella formosa) and fall (mainly Aulacoseira granulata), while greenalgae and cyanobacteria had high appearance in early-summer and summer, respectively, indicating that water temperature is the most important factor influencing their growth. Stephanodiscus hantzschii and Asterionella formosa frequently occurred at low water temperature (4.5-15.0℃ and 5.4-21.6℃ , respectively) while Aulacoseira granulata and Anabaena spp. were favored by high water temperature (8.6-28.4 and 14.9-26.2℃ , respectively) and phosphorus. Additionally, Fragilaria crotonensis occurred at low nutrient conditions. Rhodomonas spp. frequently appeared year-round.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 조사지점 및 조사기간
  2.2. 물리․화학적 환경요인
  2.3. 식물플랑크톤 분석
 3. 결과 및 고찰
  3.1. 물리․화학 환경요인의 변화
  3.2. 시기별 식물플랑크톤의 변동 및 천이
  3.3. 우점종의 시기별 천이 양상
 4. 결 론
 REFERENCES

• 윤석제(국립환경과학원 한강물환경연구소) | Seok Jea Youn (Han River Environment Research Center, National Institute of Environmental Research)
• 김헌년(국립환경과학원 한강물환경연구소) | Hun Nyun Kim (Han River Environment Research Center, National Institute of Environmental Research)
• 임종권(국립환경과학원 한강물환경연구소) | Jong Kwon Im (Han River Environment Research Center, National Institute of Environmental Research)
• 김용진(국립환경과학원 한강물환경연구소) | Yong-Jin Kim (Han River Environment Research Center, National Institute of Environmental Research) Corresponding author
• 백준수(국립환경과학원 한강물환경연구소) | Jun-Soo Baek (Han River Environment Research Center, National Institute of Environmental Research)
• 이수웅(국립환경과학원 한강물환경연구소) | Su-Woong Lee (Han River Environment Research Center, National Institute of Environmental Research)
• 이은정(국립환경과학원 한강물환경연구소) | Eun Jeong Lee (Han River Environment Research Center, National Institute of Environmental Research)
• 유순주(국립환경과학원 한강물환경연구소) | Soon Ju Yu (Han River Environment Research Center, National Institute of Environmental Research)