Characteristics and influencing factors of phytoplankton community in a river of South China
The water network and hydrothermal conditions in South China are unique.Figuring the characteristics of regional phytoplankton communities and their influence by seasonal changes and land use types can provide a scientific basis for targeted prevention and control strategies of water blooms in South China.In this study,a typical river in South China was selected as the research object,and 14 investigation sites in the river were sampled and investigated for physicochemical parameters of water quality and phytoplankton during the spring in 2021 and the autumn in 2022.Combined with the land use data of each sampling site,the relationship between phytoplankton community structure,seasonal changes and land use type was analyzed.The results showed that seasonal variations and land use type could directly or indirectly alter phytoplankton densities,community structure,community stability and diversity by impacting environmental factors such as water temperature,precipitation,and nutrient levels.Changes in water temperature and the impact of rainfall on pollutants and water disturbance significantly changed the densities,community stability and diversity of phytoplankton.In terms of nutrients,redundancy analysis revealed that total nitrogen and total phosphorus were the key factors affecting the differences of phytoplankton communities(p＜0.05).The difference analysis showed that there were significant differences in total nitrogen,total phosphorus,average densities and diversity index of phytoplankton in the spring and autumn(p＜0.05).The community composition also changed from Bacillariophyta-Cyanophyta type to Bacillariophyta-Chlorophyta type.Correlation analysis showed that total nitrogen and total phosphorus were negatively correlated with forest land,while agricultural land and urban land were positively correlated.The average densities of phytoplankton in urban area was higher than that in forest area and agricultural area,and the diversity index was lower than that in agricultural area,indicating that the risk of bloom outbreak was higher in urban area.Therefore,the prevention and control of bloom outbreak should focus on the period of high water temperature and the river section with more land used by towns and villages on both sides.
phytoplanktoncommunity characteristicsseasonal changesland use types
国家科技期刊平台
NSTL
万方数据
