Abstract :
In this paper, we study the persistence of a periodic Kolmogorov system which
models the growth of n interacting biological species. The system is assumed to
have a simple dynamic, in the sense that each coordinate subsystem possesses a
global attractor. Our research is mainly addressed to the case in which there exists
at least a predator among the n species. However, we also obtain a result about
persistence for a class of competitive systems
