ISSN:
1432-072X
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Summary In Windermere, and some other lakes in the English Lake District, the vernal increase of Asterionella formosa ceases when the concentration of silica in the water falls to approximately 0.5 mg/l. When this planktonic diatom is cultivated in water from one of these lakes, Windermere, the addition of small amounts of phosphate phosphorus permits the growth of so large a crop that all the silica present is incorporated into the cells. The intensity and duration of the illumination and the temperature of the water effect this relationship between silica, phosphorus and the growth Asterionella. Therefore, the regular, observed relationship between the concentration of silica and the vernal maximum of Asterionella in nature may be related to the amount of this substance in the water, to the amount of phosphate phosphorus present and to the rate of growth imposed upon this diatom by the light and temperature conditions in the lake during the period concerned. The possible importance of the relatively low concentration of phosphate phosphorus in certain very unproductive lakes is discussed.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00408168
