The time and space dynamics of phytoplankton and its driving factors were studied in Hongfeng Reservoir, southwestern China, from March 2016 to December 2019 to explore the spatiotemporal dynamics and driving factors of the phytoplankton community structure. The structural equation model (SEM) was used to analyze the relationship between abundance of phytoplankton and environmental factors in order to determine the main environmental factors that affect changes in phytoplankton. A total of 110 phytoplankton taxa were obtained from six sites. They were members of seven phyla and 68 genera with 12 dominant species or genera. The SEM showed that the main environmental factors that affected the cyanobacteria and diatoms were the temperature (WT), total nitrogen (TN), nitrite nitrogen, nitrate nitrogen, dissolved oxygen, and transparency (SD). Those that affected the Chlorophyta were the pH, TN, ammonia nitrogen (NH₄⁺–N), and orthophosphate phosphorus (PO₄³⁻–P). We concluded that changes in the WT, SD, and the concentration of nutrients significantly affected the abundance of phytoplankton and the dominance of Cyanobacteria and diatoms, whereas these factors had insignificant effects on green algae. The WT, SD, TN and NH₄⁺–N were found to be important environmental factors that affect the structure, growth, and reproduction of the phytoplankton community in Hongfeng Reservoir. This study should provide a scientific reference for the reservoir phytoplankton community ecology and a database on the changes in water quality.

2016年3月至2019年12月在西南地区红峰水库开展浮游植物时空动态及其驱动因子研究，探索浮游植物群落结构的时空动态和驱动因子。采用结构方程模型（SEM）分析浮游植物丰度与环境因素的关系，以确定影响浮游植物变化的主要环境因素。从六个地点共获得了 110 个浮游植物类群。它们是7个门和68个属的成员，具有12个优势种或属。SEM显示，影响蓝藻和硅藻的主要环境因素是温度（WT）、总氮（TN）、亚硝酸盐氮、硝酸盐氮、溶解氧和透明度（SD）。₄ ⁺ -N) 和正磷酸盐 (PO ₄ ^3- -P)。我们得出结论，WT、SD 和营养物质浓度的变化显着影响浮游植物的丰度以及蓝藻和硅藻的优势，而这些因素对绿藻的影响微乎其微。发现WT、SD、TN和NH ₄ ⁺ -N是影响红峰水库浮游植物群落结构、生长和繁殖的重要环境因子。该研究可为水库浮游植物群落生态学提供科学参考，并为水质变化提供数据库。