Permafrost is frozen ground which never thaws.This frozen ground is important to tracking climate change through the centuries, as any temperature change leaves its mark on the permafrost.
The tundra begins at the tree line. There are no trees in the tundra. The tundra's long summer days allow a variety of plants to thrive. Tundras are teaming with grasses and wild flowers, and rocks are covered in lichen. These plants all represent life thriving in one of the most extreme climates on earth.
The caribou and the reindeer, technically a single species, are spread across the entire tundra. Other creatures native to the tundra include doll sheep, brown and polar bears, and snow geese---all of which would lose their habitat were the tundra to disappear. Contrary to popular belief, there are no penguins in the tundra; penguins live in Antarctica, the farthest place away from the tundra on the planet.