Permafrost – Permanently frozen ground, found in polar and tundra regions

To remember the meaning of the term Permafrost, use the following mnemonic:

Permanently frosty (permafrost), the ground was solid, permanently frozen.

Even at the height of summer, the ground beneath the surface remains frozen in these polar and tundra regions. Plants that need deep root systems are unable to survive. The tundra can only support low-growing plants such as shrubs, mosses and lichen.

The combination of permafrost, very short summers and seasonal waterlogging – when water submerges land and makes it marshy – makes it impossible for trees to grow in these areas.