Apparent 15 N uptake kinetics resulting from remineralization 1, 2

A computer model of phytoplankton 15 N uptake experiments in which simultaneous remineralization is occurring is used to demonstrate potential artifacts if remineralization is disregarded. In simulated experiments where a range of 15 N additions is made to obtain population kinetics, apparent kinetics can be obtained where none exist. Similarly, in simulated experiments where samples are taken over time there is an apparent decrease in uptake rates with time, which, when plotted against inferred changes in substrate concentration, gives rise to similar kinetics. In actual experiments, such artifacts could obscure any real kinetics and would lead to erroneous estimates of population characteristics.