Synoptic tinkering: Integrating strategies for large-scale conservation

The geographical distribution of endangered species and threatened habitats should provide useful information for identifying areas in need of special protection. It is naive, however, to assume that the identification of endangered species "hot spots" will lead to the development of a system of reserves that most efficiently protects a maximum amount of biodiversity. To achieve this also requires information on the underlying pattern of species diversity, the distribution of threats to diversity (such as relative rates of habitat loss), and the value of land in different areas. Here we focus on information for five U.S. states for which data are available on the underlying pattern of overall species diversity in one or more taxa, human population density, and land value. We analyze data for plants in California and Texas, birds in Oregon and Iowa, and "herptiles" in Florida. Our analysis indicates that the observed distribution of endangered species reflects the modification of the underlying pattern of species diversity by anthropogenic activities. This suggests that a mixture of strategies is required to protect biodiversity; these should focus on both species and habitats. Our results indicate that, although protecting wilderness is valuable and relatively easy, conserving the most biodiversity will require greater focus on those areas that are also of highest value to humans.