Objectives; Building on past efforts; Approach; Project flow & structure; Terminology and classification scheme; Criteria for calculating index values and ranking evosystems; Graphical analyses and the development of appropriate conservation strategies; Ecoregion maps and text; Identifying ecorregions; Classification of ecoregions; Extant original habitat; Disjunct ecoregions; Endemism & "Hotspots"; The importance of beta diversity; Marine and freshwater ecosystems; Assessing conservation potential and degree of threat among ecoregions; Conservation potential; Degree of threat; Alternative schemes; Index range; Weighting criteria; Multi-national ecoregions; Criteria for five dynamically similar ecosystems (DSEs); Tropical broadleaf forests; Conifer & temperate broadleaf forests; Grasslands, savannahs, wetlands, shrublands; Xeric ecosystems; Mangrove forests; Ecoregion classifications.