[Mathematical model of a two level ecosystem].

The model which consists of two trophical levels is developed. The species here are connected by "pray--predator" relationship. If one supposes rather narrow specialisation of predator and introduces the "ecological space", the model which was preliminary recorded as a system of common differential equations of great dimension can be modified to the system of two non-linear equations in partial derivatives. Linear approach was investigated analytically, the previous nonlinear problem was calculated on a computer. The most interesting result here is an appearance of space--time oscillations in the system, which can be regarded as the first stages of ecological succession.