Dynamics of a Materially Closed Model Ecosystem

This paper deals with model ecosystem consisting of biotic and abiotic components. The biotic component was represented as populations of organisms with particular eco-physiological traits and individual properties. Interspecific relationships consisted of exploitation competition and prey-predator interactions. The system was composed of populations that consume energy, represented as amount of matter for life activities, and was closed materially. The system was studied for the conditions under which populations coexist. Results showed that the total amount of substances, represented as the summation of standing stocks of organisms and inorganic materials, was important for the coexistence of the populations. Also, if the length of the food chain were less than four, and the traits were closer to real values, the system was stable in a state of competition for the same food, regardless of the differences in the traits between the populations competing.