Phytoplankton community structure characteristics and influencing factors in major tributaries of Shaoguan section of the Beijiang River
To study the effects of land use types and water environmental factors on the phytoplankton community,phytoplankton and their influencing factors were investigated and monitored at 25 sampling sites from the Mojiang River,Jinjiang River,Wujiang River,and Nanshui River,which are major tributaries of the Shaoguan section of the Beijiang River,during January and July 2022.69 species of phytoplankton belonging to 6 phyla were detected in the dry season,while 68 species of phytoplankton belonging to 6 phyla were detected in the wet season.The number of species of Bacillariophyta and Chlorophyta during different water periods accounted for more than 80%.The average density(5.65×105 cells·L-1)and biomass(1.20 mg·L-1)of phytoplankton in the wet season were significantly higher than those in the dry season(2.89×105 cell·L-1 and 0.72 mg·L-1).The Shannon-Wiener diversity index(H′)and Margalef index(D)showed that species diversity in the dry season was higher than that in the wet season,while the Pielou evenness index(J)was similar for different water periods.pH,water temperature(WT),turbidity(TUR),permanganate index(CODMn),total nitrogen(TN),and total phosphorus(TP)were selected as key water environmental factors to participate in redundancy analysis(RDA).The proportion of land use type area from the 3 000 m buffer zone and water environmental factors had greatest explanatory ability(56.94%)for the change in phytoplankton during dry season.For the wet season,the proportion of land use type area from the 1 200 m buffer zone and water environmental factors could explain the change in phytoplankton to the greatest extent(43.91%).The results of RDA showed that WT was the major factor affecting distribution of Bacillariophyta during dry season.Chlorophyta and Cyanophyta were primarily affected by TP and CODMn.Cryptophyta was primarily affected by the proportion of forest area and pH.During wet season,Cyanophyta and Cryptophyta were primarily affected by pH,water area,and the proportion of forest area.Bacillariophyta was primarily affected by TP,CODMn,and the proportion of construction land area.Chlorophyta was primarily affected by WT and TUR.The phytoplankton influencing factors were different for different water periods.Identifying the major influencing factors is conducive to formulating reasonable water ecological restoration and protection measures to ensure phytoplankton diversity along with a healthy and balanced water ecosystem.
Beijiang Riverphytoplanktoncommunity structureland use typewater environmental factor
国家科技期刊平台
NSTL
万方数据
