Community Structure Characteristics Of Phytoplankton And Related Effecting Factors In Four Typical Habitats Of Lakes Connected To The Yangtze River,Anhui Province

Anhui Province has four distinct seasons,abundant rainfall and numerous water bodies.There are certain connectivity among water bodies,and the distribution of aquatic vegetation in different water bodies is different.In this paper,several different types of water body are divided into four habitats: natural lake habitat(Wuchang lake and Shengjin Lake),submerged vegetation habitat(jinbaowei),emergent vegetation habitat(yanwowei and Wuchang lake aquatic vegetation restoration demonstration project area),artificial fish pond habitat.Taking phytoplankton as the research object,the effects of different nutrient concentrations and different aquatic vegetation types are discussed The differences of phytoplankton community composition and its population dynamics in four habitats with different water system connectivity,such as water type,coverage and so on.Based on the data analysis,this paper compares the differences of phytoplankton community structure characteristics in four different habitats in Anhui Province,and discusses the correlation between the differences and the environmental factors of the habitats.From the ecological point of view,it provides the necessary scientific research for the ecological protection,rational utilization of resources,protection of biodiversity and future ecological restoration of wetlands in Anhui Province This is the basis.The main findings are as follows:(1)In summer,235 species of phytoplankton were detected in the four habitats,belonging to 8 phyla and 94 genera.Among them,83 species of Chlorophyta,70 species of Cyanophyta,45 species of Bacillariophyta,21 species of gymnophyta,7 species of Cryptophyta,6 species of dinoflagellate,2 species of Xanthophyta and 1 species of Chrysophyta were themost.(2)The annual average cell density of phytoplankton in the four habitats was 191.60 × 105 cells / L.according to the seasonal analysis,the change trend of average cell density of phytoplankton was as follows: Autumn > spring > winter > summer;according to the spatial analysis,the order was as follows: artificial fish pond habitat > submerged vegetation habitat > emergent vegetation habitat > Natural Lakehabitat.(3)The average annual biomass of phytoplankton in the four habitats was 9.78 mg / L.According to the seasonal analysis,the total biomass in winter was 14.03 mg / L,which was the highest among the four seasons;the total biomass in summer was the lowest,which was8.03 mg / L,and the difference was not obvious in spring and autumn.According to the seasonal analysis,the change trend of phytoplankton biomass in the four habitats was winter > autumn > spring > summer;according to the spatial analysis,the total biomass of artificial fish pond was 56.10 mg / L,which was the highest in the four habitats.According to the spatial analysis,the order is artificial fish pond habitat > submerged vegetation habitat >emergent vegetation habitat > Natural Lakehabitat.(4)Shannon Wiener distribution of phytoplankton in four habitats The average value of(H '),.According to the seasonal analysis,Shannon Wiener diversity index and marglef richness diversity index had the same change trend,in the order of summer > spring > winter > autumn,Pielou evenness diversity index had the same change trend: spring > summer > winter > autumn.According to spatial analysis,Shannon Wiener index was the highest in natural lake habitat(2.68 ± 0.24),and the lowest in artificial fish pond habitat(1.93 ± 0.51).According to spatial analysis,Shannon Wiener index and marglef richness diversity index had the same change trend,and the order was natural lake habitat > submerged vegetation habitat >emergent vegetation habitat > artificial fish pond habitat.Pielou diversity index was natural lake habitat > emergent vegetation habitat > submerged vegetation habitat >artificial fish pond habitat.(5)The physical and chemical factors of the four habitats also had significant changes according to the seasonal and spatial analysis.The results show that the water temperature reaches the peak value of 32.37 ± 0.56 ? in summer(July 2018),with obvious seasonal variation,and reaches the lowest value of 6.7 ± 0.74 ? in winter(January 2019).Turbidity reached the maximum value of 62.3 ± 65.9 NTU in spring and the minimum value of 35.5 ± 31 NTU in winter;NH4 +-N concentration in artificial fish pond habitat was the highest in winter,0.28 ± 0.31 mg /L,and the lowest in spring,0.15 ± 0.08 mg / L;Chl.A concentration was the highest in summer,4.23 ± 1.95 mg / L,and the lowest in winter,1.5 ± 0.96 mg / L.Spatially,the transparency of natural lake habitat in Tongjiang lake was 0.60 ± 0.19 M,which was significantly higher than that of other habitats(P < 0.05).The turbidity of artificial fish pond habitat was 61.5 ± 43.5ntu,and the turbidity of natural lake habitat was 33.79 ± 26.9ntu.The total phosphorus concentration of artificial fish pond habitat was significantly higher than that of other habitats,which was 0.33 ± 0.05mg/l The lowest was 0.06 ± 0.03mg/l;the p H value of artificial fish pond was 9.06 ± 0.28,which was significantly higher than other habitats(P < 0.01);the chlorophyll-a concentration of submerged vegetation habitat was 6.51 ± 4.78 ?g / L,which was significantly higher than other habitats;the electrical conductivity of artificial fish pond habitat was 218 ± 49.6 ?s / cm,and the lowest was 88.4 ± 19.1 ?s / cm.Pearson correlation analysis and redundancy analysis(CCA)showed that water temperature,transparency,turbidity,chlorophyll a,p H,nutrients and other environmental factors were closely related to the seasonal spatial dynamics of phytoplankton community structure in four habitats.