Structure And Dynamics Of Phytoplankton Community Based On The Redundancy Analysis (RDA)

In order to study the seasonal variations in the structure and dynamics of phytoplanktoncommunity of the Baiyangdian Lake in China, quantitative samples were collected in eachseason during2010to2011.The Redundancy analysis method was used to study therelationship between phytoplankton and environmental factors,so as to explore the mainfactors affecting the phytoplankton community structure in Baiyangdian Lake.The main findings were as following:1.The spatial and temporal heterogeneity of water physical and chemical factors changedwith the season. The pollution type and pollution degree of8sample sites was different,mainly as nitrogen and phosphorus pollution and organic pollution.2. Results show that209species belonging to8Phylums were identified in BaiyangdianLake. Chlorophyta accounted for36.4%of total number algae species, which had76species.Bacillariophyta accounted for20.1%of total number algae species, which had42species.Cyanophyta accounted for16.7%of total number algae species, which had35species.Euglenophyta accounted for15.3%of total number algae species, which had32species.Cryptophyta accounted for3.8%of total number algae species, which had8species.Pyrrophyta accounted for3.8%of total number algae species, which had8species.Chrysophyta accounted for2.4%of total number algae species, which had5species.Xanthophyta accounted for1.4%of total number algae species, which had3species. Theannual average cell density of phytoplankton was7509.38×104ind./L in2010and5750.00×104ind./L in2011.3. The relationship between the phytoplankton community stucture and dynamic changesand environmental factors was analysised and discussed by Redundancy analysis(RDA). Theresults showed that: water temperature and nitrogen and phosphorus were the mainenvironmental factors that affect the distribution of phytoplankton community, SD was alsothe main factor in winter. Chlorophyta can tolerate higher concentration of nitrogen andphosphorus. The density of the Chlorophyta was higher in the eutrophic lake. Cyanobacteria and Cryptophyta had a strong adaptability of high concentration of nitrogen and phosphorousnutrients and organic pollution.The most serious problem of Baiyangdian Lake is eutrophication now, and the density ofphytoplankton is too high. This survey work at a more comprehensive and detailed study ofphytoplankton community structure, and the main environmental factors that affect thephytoplankton community structure with redundancy analysis method, to provide the basis forthe protection and governance of Baiyangdian Lake. Combining the results of thisinvestigation, the recommendation on protection and governance as follow:1curbingexogenous pollutions;2controlling internal pollution;3to handle the relationship ofprotection and development validly.