ON THE PERIODIC LOTKA-VOLTERRA COMPETITION MODEL

We analyze the existence, stability, and multiplicity of T-periodic co existence states for the classical nonautonomous periodic Lotka-Volter ra competing species model. This is done by treating the average value s of the birth rates of species as parameters, and studying the global structure of the set of coexistence states as these parameters vary. As a result of this analysis, we can explain the interesting differenc es between the results for the periodic case and the associated autono mous model. (C) 1997 Academic Press.