| 摘要: |
| 对渤海调查区浮游植物的群落及其动力学进行了初步研究。结果表明， 浮游植物群落主要由硅、甲藻组成，也有少数的蓝藻、绿藻和硅鞭藻出现，其生态类型主要为温带近岸型。粒级大小以微型浮游植物为主， 依次为小型浮游植物(包括网采浮游植物) 、微微型浮游植物。浮游植物群落的平面分布与各环境因子密切相关，其中水体中化学和生物相互作用所形成的浮游植物团块是其平面分布的主要特征。调查海域存在三个典型的浮游植物区划: 渤海海峡区、渤海湾区和黄河河口区。追踪实验的结果表明，调查区浮游植物群落短周期( 几天) 的变化是由关键种所驱动而非优势种。渤海海峡浮游植物群落的周年变化为双周期型，春季水华主峰出现在4 月，而秋季次高峰出现在9 月。春季浮游植物以小型细胞硅藻占优群落为主，秋季以大型细胞硅藻-甲藻联合占优群落为主。群落季节和周年的变化以种类演替( species succession) 为主而非种类接替( species sequence) 。与历史调查资料相比， 1998-1999 年的观测表明浮游植物群落由硅藻占绝对优势逐渐转变为硅藻-甲藻共存为主的群落。甲藻的占优以及绿藻在特定时期的普遍出现反映了渤海海区营养盐结构比例变化对海区生态系统结构的影响， 氮/磷比率的增加和硅/氮比率的降低是造成这一结果的直接原因。 |
| 关键词: 浮游植物, 群落结构, 动力学, 渤海, 粒级结构, 赤潮 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目, 49576298号; 青岛海洋大学海洋生态环境教育部重点实验室开放基金资助; 国家基础研究与重点项目, G1999043703和2001CB409702号 |
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| THE PRELIMINARY STUDY ON PHYTOPLANKTON COMMUNITY STRUCTURE IN THE CENTRAL BOHAI SEA AND THE BOHAI STRAIT AND ITS ADJACENT AREA |
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SUN Jun1, LIU Dong-Yan1, YANG Shi-Min2, GUO Jian3, QIAN Shu-Ben1
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1.Marine Life Science College, Ocean University of Qingdao;2.Dong FangHong Ⅱ Research Vessel , Ocean University of Qingdao;3.Marine Fishery College, Ocean University of Qingdao
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| Abstract: |
| Phytoplankton species composition and species succession were analyzed in 1998-1999 during 2 nestle investigation cruises in the Central Bohai Sea, the Bohai Strait and adjacent waters, and two monthly monitoring stations at Penglai and Changdao for 15 months. The results show that diatoms and dinoflagellates are the major components of phytoplankton community in the survey region, with cynobacteria, green algae and siliconflagellates being also common found in some stations. The ecotype of these phytoplankters is temperate and neritic species; some warm oceanic species can be imposed from the Yellow Sea and distributed near the Bohai Strait. The size fractional features of phytoplankton community in the survey area show that nanophytoplankton was a major component and the picophytoplankton was also important (i.e., it accounted for 21.3% and 28.4% biomass separately in autumn 1998 and spring 1999). The horizontal distribution of phytoplankton in the survey area has a close relationship with physical chemical conditions in ambient waters. Three phytoplankton provinces can be discerned at the Huanghe Estuary, north of Bohai Bay and the Bohai Strait. Shortterm (days) development of phytoplankton community in the central Bohai Sea depends on the species changes of the dominant species but the key species. Annual variations of the phytoplankton community in the Bohai Strait show a typical double-peak cycle in the north hemisphere. The higher cell abundance peak is in April and the lower peak in September. In spring, the phytoplankton community is mainly made of small cell diatoms, and in autumn the phytoplankton community is characterized by big cell diatoms coexisting with dinoflagellates. The species succession was the major process of seasonal changes of phytoplankton community development pathway in the Bohai Sea. Long-term observations from 1958-1999 in the Bohai Sea show that the replacement of diatom by dinoflagellates is the main feature of phytoplankton community changes in recent years, which is indicated by N/P ratio increment and Si/N ratio decrement. Red tides are inescapable in the Bohai Sea due to the anthropogenic nutrient input and drying up of the Huanghe River. |
| Key words: Phytoplankton, Community structure, Dynamics, Bohai Sea, Size fraction, Red tides |
