||Optimum N:P Ratios and Coexistence of Planktonic Algae (Journal Version).
Rhee, G-Yull ;
Gotham, Ivan J. ;
||New York State Dept. of Health, Albany. Div. of Labs. and Research.;Environmental Research Lab.-Duluth, MN.
Diurnal variations ;
Mathematical prediction ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
The optimum atomic ratio of N to P, the ratio at which one nutrient limitation changes over the other, was determined in seven species of freshwater planktonic algae. The ratio varied over a wide range among species; the average for these species was 17. If the cellular nutrient ratios in marine species are comparable with those in freshwater organisms, Redfield's ratio of 15 is remarkably close to the average. Cellular N:P ratios varied over a 24-h period under a light:dark cycle. The variation of the optimum ratio between species and diel change in cellular N:P ratios within a species could play an important role in population dynamics by enhancing the probability of coexistence of species.