Human communities can mix like the species in a natural community. On a rocky shore, one finds groups of barnacles, mussels and whelks. Sometimes one species will dominate, as barnacles do in the area exposed at low tide. But in nature this is hardly ever to the exclusion of other species. There are always zones of transition, and a singular zoning policy (Figure 10.10) would be absurd. In landscape ecology, the most typical pattern is of patches and corridors. A patch will be a mix of plant and animal species that have learned to live together, with many symbiotic relationships. Corridors tend to be transition zones. It is a good model for contextual planning, as shown by the "patch' diagrams in (Figure 9a-f). Overlaid, the plural assemblage of zones may be confusing (Figure 9g). But each project team need only fix their eyes on the zones within which the project falls (Figure 9g).
