Climatic Conditions: Winters are long and severe, summers are cool and brief, very low mean annual temperature.
i. Conical shape, smooth leaf surface, needle leaf, sunken stomata.
ii. Evergreen and needle is a design that helps active useful working temperatures in temporarily productive periods at minimum cost of maintenance.
iii. Broad-leaved species (Maples) are deciduous.
iv. Special adaptations to restrict heat loss, e.g., trembling and vertical leaves.
v. Low species diversity, therefore, prone to pest attack.
vi. Forests covered by carpet of needles and leaf litter
Some herbivores (snow flies lepidoptera) are subject to eruptions when a section of forest has not been burned for some time.
i. Large mammalian herbivores (deer and bear) are adapted to make use of regenerating forest in burned areas for browse.
ii. Migratory animals.
iii. Aestivation, dormancy.
iv. Wolf plays an important role in checking moose caribou and deer population. When wolves are driven, moose and other plant eaters, cause devastation
On the Pacific coast a variant dominated by Douglas fir is found.