Dynamics of landscape islands: A systems simulation modeling approach

The dynamics of populations and species diversity are modeled for fragmented landscapes using System Dynamics methodology. Results provide insights for metapopulation theory, conservation biology, and landscape ecology. The plant metapopulation model shows that a metapopulation always persists when one subpopulation is above MVP, but persistence depends on interpatch immigration rate when subpopulations are all below MVP. The animal metapopulation model demonstrates that system persistence is impossible when all subpopulations are below MVP and depends on interpatch immigration rate, patch connectivity, and patch arrangement when at least one subpopulation is above MVP. Population sink effect plays a more important role in metapopulation persistence for animals than for plants.; The System Dynamics model of the MacArthur-Wilson theory of island biogeography synthesizes current perspectives and provides a comprehensive simulator for greater understanding the species diversity dynamics of real and landscape islands. Simulations suggest that different monotonic rate-species curves do not affect the essential predictions from the theory, although the equilibrium species diversity value may be greatly affected, and that non-monotonic rate-diversity curves may result in multiple equilibria. The area-based species diversity model relates static spatial data obtainable from field work to temporal dynamics of species diversity of landscape islands, incorporating effects of environmental differentiation and time delays in community-level responses. Simulations of the model show that interior and edge species respond differently to fragmentation and that changes in species diversity become obvious only when the forest island area is below some threshold.