Only plants with a shallow root system can survive. Plants with larger root systems cannot survive because the permafrost acts as a barrier to root growth.
The flat, low-land nature of these regions means that many areas become waterlogged in summer. This favours mosses that can adapt to wet and arid conditions.
Perennials keep their leaves year round to maximise photosynthesis during the short growing season.
Plants tend to have small hairs to capture heat and are low to the ground to avoid harsh cold winds.

Biodiversity in these regions is low.
Animals in cold regions tend to have large pelts and high body fat.
Most of the mammals here hibernate during the winter to avoid harsh conditions.
Many of the animals have white coats to acts as a camouflage in the snow.
Caribou have two layers of fur to keep them warm and hooves that can break ice to access water.
A high proportion of mammals and birds migrate elsewhere in the winter to stay warm.