长江口及其邻近水域叶素a的垂直格局及成因初析.PDF

植物生态学报 2009, 33 (2) 369~379 Chinese Journal of Plant Ecology 长江口及其邻近水域叶绿素a 的垂直格局 及成因初析 1, 2 1* 1 宋书群 孙 军 俞志明 (1 中国科学院海洋研究所海洋生态与环境科学重点实验室, 山东青岛 266071) (2 中国科学院研究生院,北京 100049) 摘 要 根据2005年9月～2006年5月逐季进行的4次多学科综合调查, 报道了长江口及其邻近水域叶绿素a 的垂直 分布特征, 并探讨了环境因子和长江冲淡水过程对浮游植物生物量垂直分布的影响。结果表明, 水柱平均叶绿素a 在春季最高、冬季最低, 高值区位置因季节而异, 常出现在低盐或等盐线密集的水域; 河口区和外海区水体垂向混 合均匀, 除夏季外叶绿素a 的垂直变化均较小; 冲淡水区水体呈现层化特征, 叶绿素a高值集中分布在浅层水体。低 盐的长江冲淡水占据上层水体, 良好的营养盐条件促进了浮游植物的生长; 外海高盐水控制的下层水体, 较低的 营养盐浓度和较弱的光强不利于浮游植物生物量的积累。 关键词 叶绿素a 垂直剖面 长江口 冲淡水 VERTICAL PATTERN OF CHLOROPHYLL A IN THE YANGTZE RIVER ES- TUARY AND ITS ADJACENT WATERS SONG Shu-Qun1, 2, SUN Jun1*, and YU Zhi-Ming1 1Key Laboratory of Marine Ecology Environmental Science, Institute of Oceanology , Chinese Academy of Sciences, Qingdao, Shandong 266071, China, and 2 Graduate School of the Chinese Academy of Sciences, Beijing 100049, China Abstract Aims The Yangtze River Estuary (YRE) is a complex aquatic system, and large environ- mental gradients and complicated hydrological conditions make the vertical pattern of chlorophyll a perplexing. Our aims are to 1) describe the vertical profile of chlorophyll a and 2) analyze the environ- mental factors impacting the vertical pattern. Methods Four seasonal, multidisciplinary cruises were carried out from September 2005 to May 2006 in YRE and its adjacent waters. Chlorophyll a concentration was determined fluorometrically (Parsons et al., 1984) by means of Turner Fluorometry Model 10 (Turner Designs Inc.). Seawater temperat