Nearctic realm

The Nearctic realm is one of the eight biogeographic realms making up Earth's land surface, encompassing most of North America, including Greenland, central Florida, and the highlands of Mexico. Its southern boundary excludes most of coastal and southern Mexico, southern Florida, Central America, Bermuda, and the Caribbean islands, which belong instead to the Neotropical realm. The realm is organized into four major bioregions: the Canadian Shield, with its arctic tundra and boreal forests; Eastern North America, with temperate forests and grasslands; Western North America, with coniferous forests and deserts; and Northern Mexico, with a mix of forest and desert ecosystems. Historical land bridges across the Bering Strait link the Nearctic biogeographically to Eurasia's Palearctic realm, together forming what scientists sometimes call the Holarctic realm, a shared northern heritage that distinguishes it from the tropical regions to its south. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/