THE PROMISE AND LIMITATIONS OF SPATIAL MODELS IN CONSERVATION BIOLOGY

We review the application of spatially explicit models to conservation biology, and discuss several problems regarding the use of these mode ls. First, it is unclear whether increasing the complexity of spatial models to include age structure enhances our ability to predict popula tion growth in temporally varying environments. Second, if simulations of individual behavior are used to identify options for landscape man agement, predictions about the fate of dispersing organisms are likely to be hugely in error unless dispersal attributes are known to a far greater degree of accuracy than is reasonable to expect. Third, the co mpelling metaphor of extinction debts resulting from habitat destructi on in competitive communities stands firm as a cautionary tale even wh en the metapopulation models include multiple trophic levels - but the question remains of how widespread and tight are the tradeoffs betwee n dispersal capacity and competitive superiority. Given the shakiness of spatial models as a foundation for specific conservation recommenda tions, we conclude they may be more useful as a tool for exploring the design of spatially-structured monitoring schemes, so that management mistakes might be detected before they become irreversible.