Phytoplankton Community Structure and Its Relationship with Environ-mental Factors in Caohai Lake,Guizhou,China
In recent years,the aquatic ecosystem of Caohai Lake in Guizhou Province has significantly changed with the deterioration of water quality and lake ecosystem health.Phytoplankton is an important indicator of aquatic ecosystem.It is of great significance to investigate the phytoplankton community structure and its relationship with environmental factors in understanding the ecological status and developing feasible restoration measures for the Lake.This study conducted sampling surveys on the species,cell density and biomass of phytoplankton and water quality during different seasons in 2021.The results indicated that a total of 78 phytoplankton species were identi-fied,belonging to 7 phyla.The abundance and biomass of phytoplankton were(3.89±2.08)×107～(2.38±8.01)×108 cells·L-1 and(12.46±5.49)～(29.78±8.01)mg·L-1,respectively,showing seasonal changes in summer＞autumn＞spring＞winter.The composition of dominant species varied seasonally.Microcystis sp.,Pseudoanabaena sp.,Scenedesmus Meyen sp.and Cyclotella sp.were the dominant species all year round.The overall mean Shannon-Wiener diversity index(H')of phytoplankton ranged from 1.71 to 2.63,with an annual average of 2.20 The overall mean Pielou evenness index(J)ranged from 0.52 to 0.78,with an annual average of 0.67.The overall mean Margalef species richness index(Dm)ranged from 1.30 to 1.62,with an annual average of 1.46.And the comprehensive evaluation of water ecology showed the water quality was in eutrophication.The results of Pearson correlation analysis revealed that the main environmental factors were dissolved oxygen(DO),permanganate index(CODMn),total nitrogen(TN)and total phosphorus(TP).Redundancy analysis(RDA)and Pearson correlation analysis of phytoplankton community characteristics and environmental factors indicated that the key environmental factors affecting phytoplankton were TP and DO.Compared with the ecological survey of Caohai Lake since 2004,there exists a significant change in phytoplankton communities with an obvious increase in algal cell abundance in 2021,which is a key node for the transition from macrophyte-to phytoplankton-dominated state.Timely measures should be taken to promote the restoration of submerged macrophyte and prevent occurrence of algal blooms.
Caohai Lakecharacteristics of phytoplankton speciesseasonal patternsenvironmental factors
NETL
NSTL
万方数据
