春秋两季西大洋水库生态修复示范区浮游植物群落结构特征

Community structure of phytoplankton in demonstration area for ecological restoration in Xidayang Reservoir in spring and autumn

为了解西大洋水库示范区内春秋两季浮游植物种类、丰度和生物量变化,分别于2018年10月秋季及2019年5月春季进行了调查。结果表明:秋季共检出浮游植物7门53属93种(含未鉴定种),生物量为30.34 mg/L,浮游植物密度为4745.39×104 cells/L;春季共鉴定出8门52属82种(含未鉴定种),生物量为1.19 mg/L,浮游植物密度为367.52×104 cells/L;春秋两季优势种更替较为明显,相似度仅为11.7%;生物多样性分析显示,春、秋两季Shannon-Wiener多样性指数(H′)分别为3.87、4.19,为典型的蓝-绿藻为主的群落结构;Pearson相关性分析显示,春秋季节浮游植物密度和生物量与NH+4-N、SD和pH呈显著负相关(P<0.05),与水温(T)、Chl-a、CODMn、NO-3-N、NO-2-N呈极显著正相关(P<0.01)。研究表明,西大洋水库示范区浮游植物多样性较好,群落结构较稳定,修复工程对示范区内浮游植物群落结构有积极作用。

Community structure of phytoplankton was surveyed at 8 sampling sites in ecological floating island,artificial fish nest area,and littoral restoration zone in demonstration area for ecological restoration in Xidayang Reservoir in October 2018 and May 2019 in order to understand the changes in phytoplankton species,abundance and biomass in the demonstration area in Xidayang Reservoir in spring and autumn.A total of 93 species of phytoplankton(including uncertain species),and 53 genera in 7 phyla were observed in autumn,with biomass of 30.34 mg/L and density of 4745.39×104 cells/L.Totally,82 species of phytoplankton(including uncertain species),52 genera in 8 phyla were found in spring,with biomass of 1.19 mg/L and density of 367.52×104 cells/L.There was significant dominant species succession both in spring and autumn,with the similarity of only 11.7%.The Shannon-Wiener diversity index(H′)was shown to be 3.87 in spring and 4.19 in autumn,showing a typical community structure dominated by members in Cyanophyta-Chlorophyta.The Pearson correlation analysis revealed that the phytoplankton density and biomass were very significantly positively correlated with temperature(T),and levels of Chl-a,CODMn,NO-3-N and NO-2-N(P<0.01),and negatively correlated with levels of NH+4-N,SD,and pH(P<0.05)in spring and autumn.The findings indicated that the phytoplankton diversity and community structure were in good performance in the Xidayang Reservoir demonstration area,and the restoration project had a positive effect on the phytoplankton community structure in the Xidayang Reservoir demonstration area.