Modeling the risks of nonindigenous species introductions using a patch-dynamics approach incorporating contaminant effects as a disturbance.

摘要: The establishment and spread of invasive or nonindigenous species has caused concern from stakeholders in affected areas, prompted many field modeling studies. We used stochastic two species, circular three patch dynamic models to investigate the patterns invasion impacts upon species. Both persistent degradable toxicants were incorporated as parts model system act disturbance regimens. There is a clear series that result these simulations. Competition increases population variability, but decreases number distinct outcomes possible same initial conditions. Isolation introduction was main determinant successful through process we call beachhead effect. Coexistence often local patches, contrary analytical solutions Lotka-Volterra equations numerous Contaminants their resultant disturbances are important contributors nature models. stochasticity leads variety some sets Different have different probabilities occurrence dependent specific conditions simulation. A pattern apparent "beachhead effect," where establishes within relatively remote before migrating remainder landscape. make predictions provide research hypotheses causes effects establishment, spread, impacts.