| The relationship between plankton diversity and water environment has become a research hotspot of many scholars in recent years.Although there are many studies on plankton and water environment,there are few systematic studies on plankton and water environment in Taiyuan Fenhe scenic area.In this study,the water quality of Taiyuan Fenhe scenic spot was analyzed by monitoring the seasonal and inter-regional variation of environmental factors.The species identification and abundance statistics of plankton in Taiyuan Fenhe scenic area were carried out,and the temporal and spatial distribution characteristics of plankton communities in Taiyuan Fenhe scenic area were systematically investigated.Correlation analysis and redundancy analysis were used to explore the relationship between plankton community and environmental factors in Taiyuan Fenhe scenic spot.The prediction model was established by stepwise regression analysis to study the main environmental factors affecting chlorophyll a content in water.The main research results are as follows :(1)The average water temperature of Fenhe scenic spot in Taiyuan has significant differences among different seasons,while there is no significant difference among regions.The water is weakly alkaline throughout the year,the seasonal difference is not obvious,and the regional difference is large.There were significant differences in phosphate content between seasons and regions.The dissolved organic carbon content in autumn was the lowest in the whole year,and its content was significantly different among regions.The content of chlorophyll a was the highest in summer and autumn,and the lowest in winter.There was a significant difference in the content of chlorophyll a between regions,indicating that the phytoplankton growth in Taiyuan Fenhe scenic area in summer and autumn.The results showed that the water quality of Fenhe scenic area in Taiyuan was polluted to a certain extent during the investigation period,and the water quality was poor.The annual nutrient content was high,which belonged to nutrient-rich water body.(2)According to the observation identification and metagenomic sequencing analysis,8 phyla 163 genera,8 phyla 181 genera,8 phyla 140 genera and 4 phyla 40 genera of phytoplankton were identified in Taiyuan Fenhe scenic spot in spring,summer,autumn and winter in 2019.The species composition of phytoplankton throughout the year was dominated by green algae,diatoms and cyanobacteria.Four phyla 41 genera,four phyla 55 genera,four phyla 39 genera and four phyla 17 genera were identified in spring,summer,autumn and winter,respectively.In the annual composition of zooplankton species,rotifer species were the most,followed by linear animals,and copepods and protozoa were the least.The linear discriminant analysis of each season showed that the species with significant differences varied with seasons.The species with significant differences were identified most in autumn and least in summer.The study on plankton community showed that the water body of Taiyuan Fenhe scenic spot was between the level of mesotrophication and eutrophication.(3)Shannon-Wiener index and Chao index of Fenhe scenic spot in Taiyuan showed that the diversity of plankton community was the highest in spring and autumn,and the lowest in winter;Phytoplankton abundance is relatively high in spring,while zooplankton abundance is highest in summer.Secondly,the annual average of Shannon-Wiener index of phytoplankton was between 2.190 and 2.917,indicating that the water quality of Taiyuan Fenhe scenic spot was at a medium pollution level.(4)The correlation analysis between plankton and environmental factors showed that there were significant correlations between plankton communities and water temperature,p H,phosphate,nitrate,nitrite,dissolved organic carbon,and environmental factors affecting plankton communities were also different in different seasons.The main factors affecting phytoplankton community are nutrient salt concentration,while water temperature and p H are the main factors affecting zooplankton community.The relationship between plankton and environmental factors in Fenhe scenic area of Taiyuan was studied by detrended analysis and redundancy analysis.The results showed that in spring and winter,the greatest impact on plankton community was phosphate.Water temperature and p H were the control factors of plankton community in summer and autumn,respectively.(5)Chlorophyll a concentration in water can represent the biomass of phytoplankton to a certain extent,and its value can directly reflect the dynamic change of eutrophication degree in water.Correlation analysis between chlorophyll a and environmental factors showed that nitrite was closely related to chlorophyll a concentration.The model between chlorophyll a and environmental factors was established by stepwise regression analysis.It was found that the main environmental factors affecting chlorophyll a concentration were different in different seasons,and p H and phosphate had a greater impact on chlorophyll a concentration in four seasons. |
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