Spatial shifts in size structure, phylogenetic diversity, community composition and abundance of small eukaryotic plankton in a coastal upwelling area of the northern South China Sea
Spatial shifts in size structure, phylogenetic diversity, community composition and abundance of small eukaryotic plankton in a coastal upwelling area of the northern South China Sea
复制标题
DOI：
10.1093/plankt/fbaa046
复制
发表时间：
2020-11-01
影响因子：
2.1
通讯作者：
Dolan, John
中科院分区：
文献类型：
--
作者：
Gong, Fahui;Li, Guihao;Dolan, John
海南岛（南海北部）夏季上升流受到较新鲜的沿海水团的影响。为了评估这种复杂海洋学的生态影响，我们于 2016 年 8 月进行了一次巡航。我们调查了整个上升流系统中浮游植物大小结构、多样性和小型真核生物（0.2-20 μm）数量的空间格局。在陆架内水域，纳米浮游植物对浮游植物生物量的贡献比例高于微型浮游植物和超微型浮游植物。 18S rRNA基因高通量测序和群落分析表明，小型真核生物群落结构的水平变异大于垂直变异。表层甲藻、硅藻、纤毛虫和微胞菌的相对序列比例从内陆棚到斜坡逐渐降低，而根藻、深球菌和骨球菌则呈现相反的趋势。分类单元特异性 rDNA 拷贝数的空间模式与基于相对比例的模式相似。冗余分析表明，浊度、盐度是构建小型真核生物群落的最重要的环境变量。光合超微真核生物的细胞丰度与马氏藻纲的 rDNA 丰度显着相关，纳米真核生物的细胞丰度与甲藻和硅藻的 rDNA 丰度显着相关。
Summer upwelling off Hainan Island (northern South China Sea) is influenced by fresher coastal water masses. To assess the ecological effects of this complicated oceanography, a cruise was conducted in August 2016. We investigated the spatial patterns of phytoplankton size structure, diversity and quantity of small eukaryotes (0.2-20 mu m) across the upwelling system. In the inner-shelf waters, nanophytoplankton contributed a higher proportion to phytoplankton biomass than microphytoplankton and picophytoplankton. High-throughput sequencing of 18S rRNA genes and community analysis indicated that the horizontal variation in community structure of small eukaryotes was larger than the vertical. The relative sequence proportions of dinoflagellates, diatoms, ciliates and Micromonas in the surface layer gradually decreased from the inner shelf to the slope, whereas the Rhizaria, Bathycoccus and Ostreococcus exhibited an opposite trend. The spatial patterns of taxon-specific rDNA copy numbers were similar to the patterns based on the relative proportions. Redundancy analysis revealed that turbidity, salinity and were the most important environmental variables in structuring the community of small eukaryotes. The cell abundance of photosynthetic picoeukaryotes was significantly correlated with the rDNA abundance of Mamiellophyceae and the cell abundance of nanoeukaryotes was significantly correlated with the rDNA abundance of dinoflagellates plus diatoms.