| Abstract: | The uptake of phosphorus by Potamogeton pectinatus, P. lucens, Ranunculus fluitans, Elodea canadensis, Myriophyllum spicatum and Ceratophyllum demersum is investigated in batch tests at 0.02, 0.04, 0.4 and 4.0 mg/l PO in the medium for 4, 28 and 52 h. Uptake is strictly dependent on concentration, a saturation function being discernible already after 52 h. At rising concentration the mechanism of uptake is determined by a decreasing rate of incorporation. The rates of uptake are dependent also on the actual and maximum cell nutrient contents. Species with a low phosphorus content of <5 mg PO /g dry weight as Elodea canadensis, Potamogeton pectinatus and Myriophyllum spicatum show their maximum phosphorus incorporation at low substrate concentrations. At phosphorus contents >5 mg PO /g dry weight the phosphorus incorporation is increased only at substrate concentrations of 0.04… 0.4 mg/l PO . |
