According to one of the popular ecological theories, populations are self-governing systems, which maintain themselves in existence by utilizing “density-dependent factors”, whose effect becomes more intense as the population increases and less intense as it decreases. This theory is connected with a mathematical model developed by V. A. Bailey and A.J. Nicholson, 1935, to represent the results of the interaction of predator and prey populations. According to the theory, as expressed verbally, a disturbance of the conditions of stability – the “steady state” – produces oscillations which tend to re-establish the stable conctition. In fact, however, when numbers are inserted in the equations, the population values, at the end of one or more cycles – which increase in amplitude if there are more than one – fall below unity, which, on a common sense view may be considered to mean the extermination of the prey, followed by that of its predator or parasite.
Modeling the Effect of Density-Dependent Chemical Interference upon Seed Germination