船基围隔条件下沙尘和营养盐添加对近海浮游植物群落结构的影响

Effects of dust and nutrient additions on the phytoplankton community structures in enclosures onboard

为研究沙尘沉降和营养盐输入对中国陆架海域浮游植物群落结构的影响,于2017年3—4月在中国黄、东海进行沙尘和不同营养盐(NO_(3)^(-)、PO_(4)^(-)、尿素)添加的船基围隔培养实验。结果表明,与对照组相比,沙尘(2 mg/L)和尿素添加实验组的浮游植物群落细胞密度及群落结构变化不显著,叶绿素a含量差异不显著,优势种均为海链藻属(Thalassiosira)。不同比值的氮、磷无机营养盐添加对水体中叶绿素a含量和细胞密度的影响不同,其中氮磷比为64∶1的实验组叶绿素a含量和细胞密度最高,分别为18.20μg/L和7.86×10^(5) cells/L。沙尘和营养盐添加对浮游植物群落的影响主要表现为叶绿素a含量、细胞密度峰值及不同优势种所占比例的差异,而各个实验组的种类组成及优势种具有一定的相似性。

In order to investigate the influence of dust deposition and nutrient input on the phytoplankton community,including Chl a content,in the Chinese coastal area,incubations onboard added with artificial dust and nutrients were performed in the Yellow Sea and the East China Sea.Our results showed that the Chl a content and the phytoplankton community structure in the artificial dust and organic nitrogen input treatments were similar to those in the control with dominant species of Thalassiosira.While inorganic nitrogen and phosphate input significantly changed the Chl a content and the community structure,the treatment with the highest nitrogen input had the highest Chl a content and cell density,particularly.The important influences found were on the peak value of Chl a,cell density and the percentage of dominant species in the dust and nutrient treatments except for the species composition and dominant species which changed insignificantly.