金沙江上游叶巴滩至苏洼龙段浮游植物群落特征及影响因子分析

Analysis of phytoplankton community characteristics and their relationship with environmental factors from Yebatan to Suwalong in the upper reaches of Jinsha River

为探明金沙江上游叶巴滩至苏洼龙段浮游植物群落特征及其与环境因子的关系,于2019年平水期(5月)和丰水期(8月)对设置的13个断面进行浮游植物群落调查,并运用冗余分析(RDA)研究了浮游植物群落结构与环境因子之间的关系。结果显示:调查共鉴定出浮游藻类4门44属120种,其中硅藻门为优势门类。各样点浮游植物细胞密度和生物量平均值分别为0.13×10^(6) cells/L和0.08 mg/L。t检验表明丰水期浮游植物种类、细胞密度、Shannon-wiener多样性指数和Margalef丰富度指数均显著高于平水期。冗余分析(RDA)显示:在平水期,N营养盐(TN、NH_(3)-N)和pH是影响浮游植物空间分布的最主要因素;在丰水期,除N营养盐(NH3-N)和pH外,水温(WT)和溶解氧(DO)也是影响浮游植物空间分布的关键因素。

The phytoplankton community survey was conducted at 13 sections in normal season(May)and wet season(August)in 2019 to explore the phytoplankton community characteristics and its relationship with environmental factors in the Yebatan-Suwalong section of the upper Jinsha River.The survey results used redundancy analysis to study the phytoplankton community structure and its relationship with environmental factors.The results showed that a total of 120 species in 44 genera of 4 phyla of phytoplankton were identified,among which diatoms were the dominant phyla.The average density and biomass of phytoplankton cells were 0.13×10^(6) cells/L and 0.08 mg/L.t-test results showed that phytoplankton species,cell density,Shannon-Wiener diversity index and Margalef richness index in wet season were significantly higher than normal season.RDA analysis showed that N nutrients(TN,NH_(3)-N)and pH were the most factors affecting the spatial distribution of phytoplankton in the normal season.In the wet season,water temperature(WT)and dissolved oxygen(DO)were also the key factors affecting the spatial distribution of phytoplankton,in addition to N nutrients(NH_(3)-N)and pH.