Competitive growth of blue-greens and diatoms (Fragilaria) in the Saidenbach Reservoir, saxony

摘要: Since 1975, different patterns of the growth Fragilaria and Cyanobacteria in mid or late summer have been observed Saidenbach Reservoir. In most years, there was a mutual exclusion mass growths these two groups. High yields caused low blue-greens vice versa. first always to achieve growth, followed by Cyanobacteria. Then, last were succeeded . Only some large simultaneous both It has shown, that supply silicon phosphorus immediately before controlled pattern succession midsummer period. Mostly, Si:P ratio regulating factor, but also years which absolute concentration level nutrients either non-limiting high below minimum resource necessary compensate for losses. cases, lost its controlling function. Other influencing factors are discussed, particular effect turbulent mixing. The special nutrient conditions not only determined external load Si depletion during spring development diatoms other than , mostly is physically controlled. Therefore, sensitive meteorological extent.