Tundra is the vast, flat, treeless region in the Arctic where the land remains frozen year-round. It spans from Greenland to parts of Alaska, northern Canada, and northern Russia between latitudes 75° N and 60° N. Tundra has very low annual rainfall and average temperatures that remain below freezing for most of the year. Typical tundra plants include flowers, lichens, and cushion plants that form tight mounds to protect themselves from the cold. Common tundra animals are polar bears, arctic foxes, musk oxen, lemmings, and birds like snowy owls and arctic swans. Caribou herds migrate between tundra and southern