This note presents a mathematical model using values far abundance to express the rate of natural regeneration in tropical forests. The proposed model is the following:
tr = { (A1/A0) - 1 }. 100, where:
tr = rate οf natural regeneration in percent;
A = abundance, as definid by Jardim (1985);
A1 = A0 + ne - ns = final abundance;
Α0 = initial abundance;
ne = in put of new individuals during the study period, by germination or change in size class;
ns = out put of individuals during the study period, by death or change in size class;
1 = constant which indicates mortality.
The results show that the forest is in a dynamic equilibrium, because the rate of natural regeneration was found to be + 0,10%. This rate can be used to describe the behavior of species, groups of species, or for the forest as a whole.