Characteristics of Phytoplankton Communities and Their Relationship to Water Environmental Factors in the South Dongting Lake in the Normal Water Period
The south Dongting Lake is a typical river-communicating lake.After September every year,it gets into the normal water period,the water level drops,a large number of marshlands are exposed,and the water environment changes.In order to investigate the health status of water environment in the south Dongting Lake during the normal water period,samples were collected in three lake areas from September to October 2020,to study the characteristics of phytoplankton communities and their relationship with environmental factors,and to evaluate the water quality.The results showed that a total of 49 species of phytoplankton belonging to 35 genera and 6 phyla were detected in the Dongnan Lake,the Wanzi Lake,and the Hengling Lake,and the number of phytoplankton species in the Dongnan Lake was the highest,with 29 species of 23 genera.The average abundance of phytoplankton was 34.22× 104 cells/L,with the Hengling Lake having the highest value(42.05× 104 cells/L).The average biomass of phytoplankton was 0.54 mg/L,with the Hengling Lake having the highest(0.61 mg/L).The dominant species of phytoplankton in the three lakes were mainly Microcystis densa.The Dongnan Lake and the Wanzi Lake had more dominant species of phytoplankton,while Hengling Lake had the least.The Shannon-Wiener diversity index,Margalef richness index and comprehensive trophic level index(TLI)ranged from 2.60 to 2.84,0.64 to 0.72 and 61.95 to 65.74,respectively,indicating that the water body of the south Dongting Lake was in a state of medium eutrophication-β moderate pollution,with the Hengling Lake being the most severely polluted.Redundancy analysis showed that water temperature,permanganate index and total nitrogen concentration were the main environmental factors affecting the spatial distribution of phytoplankton in the south Dongting Lake.This study provided data support for the ecological protection and restoration of large river-communicating lakes,as well as the monitoring and early warning of watershed ecosystems.
the south Dongting Lakephytoplanktoncommunity structureenvironmental factorsredundant analysis
NETL
NSTL
万方数据
