Study On Seasonal Variations And Influencing Factors Of Phytoplankton In Three Different Types Of Wetlands In Wuhan

Kuzhuhai Lake,Wanglang Lake,and Waisha Lake are three different types of lakes in Wuhan.In recent years,water environmental problems have become more serious.In order to explore the water quality and phytoplankton community changes of the three lakes under different protection measures,this paper set up 14 sampling points according to the basic shape characteristics of the three lakes during 2018,and collected phytoplankton in four seasons: spring,summer,autumn and winter Analyze the phytoplankton species composition,dominant species,biomass,chlorophyll and other community parameters of the three lakes and the temporal and spatial changes of water environmental factors,and analyze the correlation and canonical correspondence between the phytoplankton community parameters,chlorophyll and water environmental factors to determine The main environmental factors affecting phytoplankton,the main research results are as follows:(1)The water temperature of the three lakes of Kuzhuhai,Wanglang Lake and Waisha Lake varies significantly with the seasons,showing autumn(27.65 ±1.12?)>summer(24.76±1.61?)>winter(16.19±0.62?)> The trend of spring(7.33±1.82?);the p H values of the three lakes of Kuzhuhai,Wanglang Lake and Waisha Lake are 7.9-9.3,7.6-8.4 and 6.8-8.5,respectively;the three lakes all show summer In autumn,the transparency of Waisha Lake is the lowest in autumn.All three lakes have the highest dissolved oxygen concentration in spring,and the dissolved oxygen concentration in autumn and winter shows a downward trend.Among them,the dissolved oxygen concentration of Waisha Lake is the lowest in autumn;Wanglang Lake ammonia nitrogen in spring The concentration is significantly higher than that of the other two lakes;excessive nitrogen and phosphorus cause water pollution and odor,which is the main reason for lake eutrophication.The concentrations of total nitrogen and total phosphorus in the three lakes were the highest in autumn,and Wanglang Lake>Waisha Lake>Kuzhuhai,and the highest total nitrogen concentration in the three lakes all exceeded 2.0 mg/L in the season(surface water type V)Water quality standard limit).(2)A total of 97 species of phytoplankton in 7 phyla were identified in the dry bamboo sea,78 species of phytoplankton in 7 phyla were identified in Wanglang Lake,and 158 species of phytoplankton in 7 phyla were identified in Waisha Lake.The community structure and biomass of phytoplankton in three lakes They are mainly Chlorophyta,Cyanophyta and Diatoms.From the perspective of biomass,the biomass of Kuzhuhai and Wanglang Lake in each season is autumn>summer>spring>winter,whileWaisha Lake is different,it is summer>autumn>spring>winter.In terms of abundance,Wanglang Lake and Waisha Lake have the highest abundance in spring,and the three lakes have the lowest abundance in winter.From the perspective of the dominant groups,the cyanophyta dominates in the Kuzhuhai and Waisha Lake in autumn,the diatoms dominate in the dry bamboo sea in winter,and the chlorophyta dominates in the spring.Wanglang Lake and Waisha Lake both dominate in winter.The phylum Chlorophyta dominates,and the phylum Cyanophyta dominates in summer and autumn in Wanglang Lake.From the perspective of dominant species,the dominant species in the dry bamboo sea throughout the year are spore algae and microalgae,the dominant species throughout the year in Wanglang Lake is euglena,and the dominant species in Waisha Lake are microalgae and platanophyta.(3)The average chlorophyll-a content in summer was 86.72 UG / L,which was significantly higher than that in other seasons.The average chlorophyll-a content of kuzhuhai Lake in spring was 32.06 UG / L,which was significantly higher than that in spring.The average chlorophyll-a content in summer was 240.30 UG / l was about 8times higher than that in spring;the spatial variation of Wanglang lake and Waisha lake was higher than that of northeast lake,while that of kuzhuhai lake was higher than that of southern Lake.(4)The annual average species diversity of phytoplankton in the three lakes was the highest in spring.From summer to winter,kuzhuhai lake and Waisha Lake showed the same trend.The species diversity of Wanglang Lake did not change significantly with the seasons.In terms of spatial distribution,the species diversity index of Wanglang lake and Waisha Lake were lower in the west of Lake area in autumn,while that of kuzhuhai lake and Waisha lake was lower in summer.(5)The biomass parameters(chlorophyll-a,cell density,biomass)of phytoplankton in kuzhuhai were mainly affected by water temperature,p H,permanganate and water depth,and species diversity was mainly affected by water temperature,transparency and nitrate nitrogen.Phytoplankton biomass parameters(chlorophyll a,cell density,biomass)in Wanglang Lake were mainly affected by water temperature,p H,transparency,ammonia nitrogen and water depth,and species diversity was mainly affected by dissolved oxygen,total nitrogen and nitrate nitrogen.The biomass parameters(chlorophyll,cell density,biomass)of phytoplankton in Waisha Lake were mainly affected by water temperature,p H,transparency,dissolved oxygen,total nitrogen and nitrate nitrogen,and species diversity was mainly affected by ammonia nitrogen,nitrate nitrogen,electrical conductivity and water depth.(6)The results showed that the growth of Chlorophyta,Bacillariophyta andCyanophyta was significantly affected by water temperature in kuzhuhai Lake;nitrate nitrogen had a significant effect on the growth of Chlorophyta and bacillariophyta in Wanglang Lake;water temperature had a significant impact on the growth of Cyanophyta,while p H had a significant impact on the growth of gymnophyta;ammonia nitrogen in Waisha lake had a significant effect on the growth of Chlorophyta,Cyanophyta and bacillariophyta in phytoplankton Significant impact.