Stability of stationary conditions of some population models with variable coefficients

There have been conducted a research of stability of stationary conditions of some mathematical models with variable coefficients which describe the dynamic of number of isolated and interacted populations. The case studies have been examined, when these coefficients have a limit if $t\to+\infty$ or when these are periodic functions, satisfying Lipschitz's condition with a sufficiently small Lipschitz's constant. Continuous models as well as discrete ones have been researched.