A comprehensive assessment of biodiversity in the US and Canada. The authors, scientists with the World Wildlife Fund, use a rigorous ecoregion approach, rather than the less relevant state-by-state approach. Six chapters present the rationale for the approach, defining the ecoregions and analyzing the threats to each. From this the authors develop a conservation agenda and set out recommendations for preserving and restoring biodiversity to the continent. Thirteen colour maps provide essential information about each ecoregion and its biodiversity.