The tundra is a very cold biome located near the North Pole. It covers a fifth of the Earth's surface. The tundra has an average temperature of below 10 degrees Celsius year-round, making it too cold for trees to grow except for dwarf willows. When the sea freezes in the tundra, the salt forms ice flowers due to the extremely low temperatures. Despite the cold, various animal species have adapted to survive in the tundra, including polar bears, arctic hares, caribou, and snowy owls.