United States

United States, spanning Arctic tundra to tropical Hawaii, ranks among Earth’s most biodiverse nations. Its vast landscapes host 400+ mammal species (e.g., bison, grizzlies), 1,100+ birds (bald eagles to flamingos), and the world’s largest temperate rainforest (Alaska’s Tongass). Hotspots like the California Floristic Province and Appalachian forests teem with endemic species, while coral reefs (Florida Keys) and deserts (Sonoran) add ecological depth. Though challenged by urbanization, the U.S. leads in conservation with 63 national parks and endangered species acts—protecting natural heritage from redwoods to prairie ecosystems.