• EMIGRATION EFFECT ON A SINGLE SPECIES ECO SYSTEM

Abstract

This paper deals with a single species ecosystem with emigration. This can be characterized by a mathematical model equation , where N is the population strength at a time‘t’, ‘K’ is the carrying capacity  and ‘Kb’ is natural birth rate of species assumed to be constants. Further f (N) denotes the Emigration function. The birth rate and the carrying capacity of the species are effected by the emigrants. The equilibrium points are disturbed and also their stability criteria included Special cases of emigration function considered are when emigration function f (N) is

(i) A constant (ii) linear in N  (iii)  proportional to

In each of the cases the effective birth rate, carrying capacity are computed, equilibrium points are identified, criteria of stability established, the trajectories are illustrated, the threshold results are stated.