ABSTRACT
Cyanobacteria, the ecologically important organisms, are a dominant flora of wetland soils, especially in rice-paddy fields where they serve as natural biofertilizers by virtue of their nitrogen- fixing ability utilizing the enzyme nitrogenase. Frequency and intensity of rainfall events will increase with longer drought periods in between promoting cyanobacterial growth due to a greater nutrient input into water bodies during heavy rainfall events, combined with potentially longer periods of high evaporation and stratification. Phytoplankton communities of lakes are thought to be effected by changes taking place in climate recently and relative abundance of cyanobacteria will increase under the predicted future climate. Effects of different environmental factors, such as ocean acidification, warming, ultraviolet radiation, pollution, eutrophication, in a combined manner on cyanobacteria are unclear. The chapter discusses the effects of the ecological stress factors on ecologically and economically important primary producers, cyanobacteria.
