Using a Monte Carlo approach we study a simple lattice model of populations living in a habitat where the external conditions are changing in space and in time. We show that above a certain value of the climatic gradient, the population gathers at a restricted part of the lattice. The average...

The influence of habitat destruction on a population of predators and prey is studied. We show, via Monte Carlo simulations of a lattice model, that with growing devastation the oscillations in the densities of both species, as well as cross-correlations between the two densities diminish. As...