BIOTIC COMMUNITIES OF NORTH AMERICA

Source: Brown, David , editor, 1994, Biotic Communities: Southwestern United States and Northwestern Mexico: Appendix I, pp. 302ff. Salt Lake City: University of Utah Press

Biogeographic REALM

1,000 = Nearctic (Biogeographic Realm -- continental North America outside the Tropics, plus some highland tropical and subtropical areas in and adjacent to the North American Southwest and the Caribbean); 2,000 = non-tropical Eurasia & Africa north of the Sahel; etc.

First digital level: VEGETATION TYPE

1,100 = Upland vegetation; 1,200 = Wetland vegetation

Second Level: FORMATION TYPE (Upland vegetation focus)

(1,)120 = Forest Formation; (1,)130 = Scrubland Form.; (1,)140 = Grassland Form.; (1,)150 = Desertland Form.

Third Level: WORLD CLIMATIC ZONE

1 = Arctic-Boreal; 2 = Cold Temperate; 3 = Warm Temperate; 4 = Tropical-Subtropical

(this classification cuts across Formation Type)

Examples: 123 = Warm Temperate Forests and Woodlands; 132. = Cold Temperate Scrublands; 133 = Warm Temperate Scrublands; 134 = Tropical-Subtropical Scrublands; 142 = Cold Temperate Grasslands; 143 = Warm Temperate Grasslands; 153 = Warm Temperate Desertlands; 154 = Tropical-Subtropical Desertlands; etc.

Fourth Level: MAJOR BIOTIC COMMUNITY (= BIOME)

"Biomes are natural communities characterized by a distinctive vegetation physiognamy within a formation" -- not necessarily always a continuous area (which may contain several biomes). "Biomes are characterized by a distinctive evolutionary history within a formation; thus they tend to be centered in, but are not restricted to particular biogeographic regions or provinces." (Brown et al., cited above, Appendix I, p.305)

Examples: 123.3 = Madrean Evergreen Forest & Woodland; 133.3 = Interior Chaparral; 142.1 = Plains Grassland; 143.1 = Scrub-Grassland (Semidesert Grassland); 153.2 = Chihuahuan Desertscrub; 154.1 = Sonoran Desertscrub;

Fifth Level: "SERIES" -- Principal plant-animal communities (distinctive "climax plant dominants")

Examples:123.31 = Encinal (Oak) series; 123.32 = Oak-Pine Series; 143.11 = Grama Grass-Scrub Series; 143.15 = Mixed Grass-Scrub Series; 153.21 = Creosotebush-Tarbush Series; 153.23 = Sandpaperbush Series; 154.12 = Paloverde-Mixed Cacti ("Arizona uplands") Series ; etc.

Sixth Level: Distinctive Plant ASSOCIATIONS -- occurrence of particular dominent species

Examples: 143.111 = Bouteloua eriopoda-Yucca elata Association; 153.213 = Larrea divaricata-Flourensia cernua Association; 154.122 = Ambroasia deltoidea-Canegiea gigantea-mixed scrub Association; etc.