Nonlinear deterministic modelling of ecological scenarios - typical predictions and limitations

Modelling population and commwiity dynamics has evolved a lot after the early attemptsby Malthus (1798), Darwin ( 1878), Lotka ( 1925), and Volterra ( 1926). The power ofnonlinear simple deterministic models is usually that they show right directions andVolterra's principle still remain a remarkable example of that Another benefit is thatmany properties of the models can be made visible in a geometric way to scientists withlittle or limited backgrowid in mathematics.Today more is known about species response to competition, nutrient limitation,predation and what environments support longer food-chains. In this paper we show howtypical communities like competing species, predator-prey systems, and food-chainsreply to changes in the environmental parameters.