In summer the northward movement of the subtropical high pressure cell reduces precipitation. Agriculture is practised along milder coastal areas. Species diversity is low but the number of individuals is high. Permafrost is permanently frozen ground overlain by an active layer that thaws during the summer. The tundra climate is cold enough to create continuous permafrost , frozen ground with few gaps or interruptions.
Discontinuous permafrost occurs in patches and is found in the boreal forest climate.