of the relative ease with which logistical problems can be overcome. Equally, modelling has aided our understanding of ecological processes at quite small spatial scales (e.g. With and Crist, 1996). Modelling has thus become a valuable strategy for increasing our ecological understanding at both small and large spatial scales (Jackson et al., 2000). Modelling now plays several key roles in the progression and consolidation of knowledge in ecology, from cases where we are relatively knowledge- and data-poor (in which heuristic models help guide development), to cases where our knowledge and data are rich, permitting the creation of complex predictive models (Figure 7.1; Peters, 1991; Jackson et al., 2000).