A simulation study of the effect on simple ecological systems of making rate of increase of population density-dependent

A simulation study has been carried out of the effect on Lotka-Volterra type ecological systems of the presence of density-dependent terms (of the type population-square) in the corresponding differential equations. It is found, as previously believed, that such terms do stabilize such a system, but the extent of the stabilization depends on the characteristics of the species to which they are applied. The lower trophic levels of a system are more important than the upper ones, herbivores collectively usually being the most important level. The numerical properties of the several species compare in importance with the organiza tion of the system: the importance of any individual species increases with the flux of protoplasm through it; the im portance of a pair of species increases with the flux of protoplasm between them. A possible method of extending this study to approach the status of a proof is suggested.