Natura - nature actualia - actual entities Mundus Plinius - physical world Astra Plinius - celestial bodies Universe (Supercluster) Virgo-Hydra-Centaurus Supercluster (Supercluster) Virgo Supercluster (Cluster) Local Group (Galaxy) Milky Way Galaxy veter. (Spiral arm) Orion Arm (Region) Local Bubble Local Interstellar Cloud (Planetary system) Solar System (Planet-satellite system) Earth System (Planet) Earth veter. "spheres" (Earth) (Sphere) Biosphere (Earth) - zone of life "terrestrial and freshwater ecoregions" (Bioregion) New World (Biogeographic realm) Nearctic "terrestrial ecoregions" (Nearctic) (Terrestrial ecoregion) Bermuda subtropical conifer forests (Nearctic) (Ecoregion complex) California Chaparral and Woodlands (Nearctic) (Terrestrial ecoregion) Central Mexican matorral (Nearctic) (Ecoregion complex) Chihuahuan-Tehuacán Deserts (Nearctic) (Terrestrial ecoregion) Colorado Plateau shrublands (Nearctic) (Terrestrial ecoregion) Great Basin shrub steppe (Nearctic) (Terrestrial ecoregion) Mojave desert (Nearctic) (Terrestrial ecoregion) Northwest Mexican Coast mangroves (Nearctic) (Ecoregion complex) Sierra Madre Oriental and Occidental Pine-Oak Forests (Nearctic) (Terrestrial ecoregion) Snake-Columbia shrub steppe (Nearctic) (Ecoregion complex) Sonoran-Baja Deserts (Nearctic) (Terrestrial ecoregion) Tamaulipan matorral (Nearctic) (Terrestrial ecoregion) Tamaulipan mezquital (Nearctic) (Terrestrial ecoregion) Western Gulf coastal grasslands (Nearctic) (Terrestrial ecoregion) Wyoming Basin shrub steppe (Nearctic) 1.1.1.1 (Terrestrial ecoregion) High Arctic tundra (Nearctic) 1.1.1.2 (Terrestrial ecoregion) Middle Arctic tundra (Nearctic) 1.1.1.3 (Terrestrial ecoregion) Davis Highlands tundra (Nearctic) 1.1.1.4 (Terrestrial ecoregion) Baffin coastal tundra (Nearctic) 1.1.2.1 (Terrestrial ecoregion) Kalaallit Nunaat high arctic tundra (Nearctic) 1.1.2.2 (Terrestrial ecoregion) Kalaallit Nunaat low arctic tundra (Nearctic) 1.2 (Terrestrial ecoregion) Alaska-St. Elias Range tundra (Nearctic) 1.2 (Terrestrial ecoregion) Canadian Low Arctic Tundra (Nearctic) 1.2 (Terrestrial ecoregion) Interior Yukon-Alaska alpine tundra (Nearctic) 1.2 (Terrestrial ecoregion) Ogilvie-MacKenzie alpine tundra (Nearctic) 1.2 (Terrestrial ecoregion) Pacific Coastal Mountain icefields and tundra (Nearctic) 1.2 (Terrestrial ecoregion) Torngat Mountain tundra (Nearctic) 1.2.1 (Ecoregion complex) Alaskan North Slope Coastal Tundra (Nearctic) 1.2.2 (Terrestrial ecoregion) Brooks-British Range tundra (Nearctic) 1.2.3 (Terrestrial ecoregion) Beringia upland tundra (Nearctic) 1.2.4 (Terrestrial ecoregion) Beringia lowland tundra (Nearctic) 1.2.5 (Terrestrial ecoregion) Aleutian Islands tundra (Nearctic) 2 (Terrestrial ecoregion) Alaska Peninsula montane taiga (Nearctic) 2 (Ecoregion complex) Canadian Boreal Forests (Nearctic) 2 (Terrestrial ecoregion) Central Canadian Shield forests (Nearctic) 2 (Terrestrial ecoregion) Cook Inlet taiga (Nearctic) 2 (Terrestrial ecoregion) Copper Plateau taiga (Nearctic) 2 (Terrestrial ecoregion) Eastern Canadian forests (Nearctic) 2 (Terrestrial ecoregion) Interior Alaska-Yukon lowland taiga (Nearctic) 2 (Terrestrial ecoregion) Mid-Continental Canadian forests (Nearctic) 2 (Terrestrial ecoregion) Midwestern Canadian Shield forests (Nearctic) 2 (Ecoregion complex) Muskwa/Slave Lake Boreal Forests (Nearctic) 2 (Terrestrial ecoregion) Newfoundland Highland forests (Nearctic) 2 (Terrestrial ecoregion) South Avalon-Burin oceanic barrens (Nearctic) 2 (Terrestrial ecoregion) Southern Hudson Bay taiga (Nearctic) 2 (Terrestrial ecoregion) Yukon Interior dry forests (Nearctic) 3 (Terrestrial ecoregion) Alberta Mountain forests (Nearctic) 3 (Terrestrial ecoregion) Alberta-British Columbia foothills forests (Nearctic) 3 (Terrestrial ecoregion) Arizona Mountains forests (Nearctic) 3 (Terrestrial ecoregion) Atlantic coastal pine barrens (Nearctic) 3 (Terrestrial ecoregion) Blue Mountains forests (Nearctic) 3 (Terrestrial ecoregion) Cascade Mountains leeward forests (Nearctic) 3 (Terrestrial ecoregion) Central and Southern Cascades forests (Nearctic) 3 (Terrestrial ecoregion) Central British Columbia Mountain forests (Nearctic) 3 (Terrestrial ecoregion) Colorado Rockies forests (Nearctic) 3 (Terrestrial ecoregion) Eastern Cascades forests (Nearctic) 3 (Terrestrial ecoregion) Florida sand pine scrub (Nearctic) 3 (Terrestrial ecoregion) Fraser Plateau and Basin complex (Nearctic) 3 (Terrestrial ecoregion) Great Basin montane forests (Nearctic) 3 (Terrestrial ecoregion) Klamath-Siskiyou Coniferous Forests (Nearctic) 3 (Terrestrial ecoregion) Middle Atlantic coastal forests (Nearctic) 3 (Terrestrial ecoregion) North Central Rockies forests (Nearctic) 3 (Terrestrial ecoregion) Northern transitional alpine forests (Nearctic) 3 (Terrestrial ecoregion) Okanogan dry forests (Nearctic) 3 (Ecoregion complex) Pacific Temperate Rainforests (Nearctic) 3 (Terrestrial ecoregion) Piney Woods forests (Nearctic) 3 (Terrestrial ecoregion) Puget lowland forests (Nearctic) 3 (Terrestrial ecoregion) Sierra Juarez and San Pedro Martir pine-oak forests (Nearctic) 3 (Terrestrial ecoregion) Sierra Nevada Coniferous Forests (Nearctic) 3 (Terrestrial ecoregion) South Central Rockies forests (Nearctic) 3 (Ecoregion complex) Southeastern Coniferous and Broadleaf Forests (Nearctic) 3 (Terrestrial ecoregion) Wasatch and Uinta montane forests (Nearctic) 4 (Terrestrial ecoregion) Allegheny Highlands forests (Nearctic) 4 (Ecoregion complex) Appalachian and Mixed Mesophytic Forests (Nearctic) 4 (Terrestrial ecoregion) Central U.S. hardwood forests (Nearctic) 4 (Terrestrial ecoregion) East Central Texas forests (Nearctic) 4 (Terrestrial ecoregion) Eastern forest-boreal transition (Nearctic) 4 (Terrestrial ecoregion) Eastern Great Lakes lowland forests (Nearctic) 4 (Terrestrial ecoregion) Gulf of St. Lawrence lowland forests (Nearctic) 4 (Terrestrial ecoregion) Mississippi lowland forests (Nearctic) 4 (Terrestrial ecoregion) New England-Acadian forests (Nearctic) 4 (Terrestrial ecoregion) Northeastern coastal forests (Nearctic) 4 (Terrestrial ecoregion) Ozark Mountain forests (Nearctic) 4 (Terrestrial ecoregion) Southern Great Lakes forests (Nearctic) 4 (Terrestrial ecoregion) Upper Midwest forest-savanna transition (Nearctic) 4 (Terrestrial ecoregion) Western Great Lakes forests (Nearctic) 4 (Terrestrial ecoregion) Willamette Valley forests (Nearctic) 5.1.1 (Terrestrial ecoregion) Canadian Aspen forests and parklands (Nearctic) 5.1.2 (Terrestrial ecoregion) Montana Valley and Foothill grasslands (Nearctic) 5.1.3 (Ecoregion complex) Northern Prairie (Nearctic) 5.1.4 (Terrestrial ecoregion) Northern mixed grasslands (Nearctic) 5.1.5 (Terrestrial ecoregion) Northern tall grasslands (Nearctic) 5.2.1.1 (Terrestrial ecoregion) Palouse grasslands (Nearctic) 5.2.1.2 (Terrestrial ecoregion) California Central Valley grasslands (Nearctic) 5.2.2 (Terrestrial ecoregion) Western short grasslands (Nearctic) 5.2.3 (Terrestrial ecoregion) Central tall grasslands (Nearctic) 5.2.4 (Terrestrial ecoregion) Central forest-grasslands transition (Nearctic) 5.2.5 (Terrestrial ecoregion) Central and Southern mixed grasslands (Nearctic) 5.2.6 (Terrestrial ecoregion) Flint Hills tall grasslands (Nearctic) 5.3 (Terrestrial ecoregion) Edwards Plateau savanna (Nearctic) 5.3 (Terrestrial ecoregion) Texas blackland prairies (Nearctic)