Effects Of Nitrogen And Phosphorus Nutrients On Interspecific Competition Of Four Algaes In Hanjiang River

The importance of competition in community construction and its mechanism of action have always been the focus of attention of ecologists,and a large number of studies have been carried out in terrestrial ecosystems.Phytoplankton is a primary producer in aquatic ecosystems,and changes in population and changes in community structure directly affect the structure and function of aquatic ecosystems.In recent years,thephenomenon of eutrophication in major waters of China has gradually intensified,and water pollution and human poisoning have emerged in an endless stream.Nitrogen and phosphorus are the most important controlling factors for the growth and proliferation of algae.The influence of nitrogen and phosphorus nutrient changes on algae growth has attracted more and more attention from the public,and has become a research hotspot in China and even the world's environmental science.In this paper,we selected four kinds of algae in the AnKang reservoir,such as Chlorophyta,cyanobacteria-Chlorella vulgaris,Phormidium corium,Scenedesmus quadricauda and Phormidium corium flos-aquae(Wittr).Kirchner,rely on laboratory research,from nitrogen source ratio,Nitrogen and phosphorus forms and nitrogen and phosphorus concentrations were studied in three competitive systems:Chlorella vulgaris and S.cerevisiae,Chlorella vulgaris and Microcystis aeruginosa,and Microcystis aeruginosa and Microcystis aeruginosa.The relationship between competition,the status of several algae in competition,and the changes of nitrogen and phosphorus nutrients on algae interspecific competition explored the relationship between algal biomass and nitrogen and phosphorus nutrients in freshwater algae.The main findings of this paper are as follows:(1)Effect of nitrogen to phosphorus ratio on algae grovwth and competition.In the green-green competition system,the degree of competition is:25:1>15:1>5:1.The higher the ratio of nitrogen to phosphorus,the more likely it is to compete and the more competitive,and the four-tailed algae has always been in a competitive position.In the blue-green competition system,the degree of competition is:25:1>15:1>5:1,the competition is fierce,and the competition is more likely to occur in the case of higher nitrogen-phosphorus ratio,and the ordinary chlorella has been competing.The dominant position,but the intensity of competition is not much increased,indicating that the nitrogen-phosphorus ratio is not particularly large for the competition of the two algae.In the blue competition system,the degree of competition is:25:1>15:1>5:1,the competition is extremely fierce,and the competition is more likely to occur when the ratio of nitrogen to phosphorus is higher.When the ratio of nitrogen to phosphorus is 5:1,The skin-like algae is in a competitive position.When the ratio of nitrogen to phosphorus is 15:1 and 25:1,the microcystis is in a competitive position(2)The effect of nitrogen source morphology on algae growth and competition.In the green-green competition system,the degree of competition is as follows:when the nitrogen source is sodium nitrate,the four-tailed cyanobacteria are in a competitive position.When the nitrogen source is ammonium chloride or urea,the common chlorella is in a competitive position,and the nitrogen source is The competition is more intense with ammonium chloride.In the blue-green competition system,the degree of competition is as follows:when the nitrogen source is sodium nitrate,the common chlorella is in a competitive advantage.When the nitrogen source is ammonium chloride or urea,the microcystis is competitive and the nitrogen source is chlorine The competition is more intense when ammonium is used.In the blue competition system,the degree of competition is as follows:when the nitrogen source is sodium nitrate,the skin-like algae is in a competitive advantage.When the nitrogen source is ammonium chloride or urea,the microcystis is competitive and the nitrogen source is chlorine.The competition is more intense when ammonium is used(3)The effect of phosphorus source morphology on algae growth and competition.In the green-green competition system,the degree of competition is:when the phosphorus source is potassium dihydrogen phosphate,the four-tailed algae is in a competitive advantage,and the phosphorus source is when the phosphorus source is sodium glycerophosphate or ATP,the common chlorella has a competitive advantage and The competition is more intense when the phosphorus source is sodium glycerophosphate.In the blue-green competition system,the degree of competition is:when the phosphorus source is potassium dihydrogen phosphate or ATP,the common chlorella is in a competitive advantage and the competition is more intense when the phosphorus source is ATP.When the phosphorus source is sodium glycerol phosphate,the water is Microcystis has a competitive advantage.In the blue competition system,the degree of competition is as follows:the phosphorus source is sodium glycerophosphate or potassium dihydrogen phosphate,and the common chlorella is in a dominant position.When the phosphorus source is ATP,the microcystis is the dominant alga.(4)The effect of nitrogen and phosphorus concentration on algae growth and competition.In the green-green competition system,the degree of competition is:medium-low nitrogen-phosphorus group>high-nitrogen phosphorus group>low-nitrogen phosphorus group>medium-high nitrogen-phosphorus group.In the low-nitrogen phosphorus group,the four-tailed algae is more competitive and competitive.The effect is small,and in the high nitrogen and phosphorus group,common chlorella is more competitive.In the blue-green competition system,the degree of competition is:medium-high nitrogen-phosphorus group>middle-low-nitrogen-phosphorusgroup>low-nitrogen-phosphorusgroup>high-nitrogen-pho sphorus group,and common chlorella is more competitive in the case of the highest concentration of nitrogen and phosphorus.Microcystis aeruginosa is more competitive when the concentration of nitrogen and phosphorus is low.In the blue competition system,the degree of competition is as follows:low nitrogen and phosphorus groups>medium and low nitrogen and phosphorus groups>high nitrogen and phosphorus groups>medium and high nitrogen and phosphorus groups.When the nitrogen and phosphorus concentrations are low,the microcystis is more competitive.The degree of competition is severe;when the ratio of nitrogen to phosphorus is high,the skin has a competitive advantage,and the higher the competition,the more intense the competition.