Abstract
Different protozoa taxa present in soil aggregates were counted by a modification of the ring method described by Singh (1946), and the number of positive rings was simulated by the following model:
Nt=N∞[1-e-k(t-tr)] (t>tr)
where Nt is the cumulative number of positive rings at time t, N∞ is the expected total number of positive rings at infinite time, k is the rate of appearance of positive rings, and tr is the retardation time. Data sets from short time observations of the aggregates closely fitted with the calculated curves of the model. Nt of mixed population of flagellates or small ciliates increased according to a stepwise curve, in which each step may correspond to a different species group.
