Spruce–fir forests

[5] Forests of the Southern Appalachian Mountains had covered approximately 140 square kilometres (54 sq mi) on peaks and ranges.

[6] The Waterrock Knob fire was composed of different group of plant species than are normally found in burned spruce and fir forests.

These vegetation characteristics suggest that possibly a hot fire in conjunction with a steep rocky slope and shallow soils have been some of the reasons for the reduced development of a typical spruce and fir stand.

In the years following the fire, precipitation combined with short term ash and nutrient influx led to a stunning display of wild flowers on the burned areas.

[12] This creates a heterogeneous, diverse stand structure which leads to an assortment of fire types which usually leave patches of unburned trees.

[9] It may be much more difficult for fir and spruce to be established on a slope, not only because of the dispersion technique, but also because erosion is greatly increased by fire, making it harder for the seeds to take root.

[13] Spruce has a much lower establishment rate, but the larger basal area increases its chances of survival and allows it to regenerate by both wind dispersion and growth from the roots remaining after a fire.

The fungus Amylostereum areolatum weakens trees and allows insects such as the Sirex noctilio (European wood wasp) to take over massive numbers of forests.

Bark beetles are the most common insect killer of spruce and fir forests because they can spread quickly, breed rapidly, and can easily devour thousands of acres before actions can be taken against them.

[16] A number of larger animals are supported by fir and spruce forests, such as moose, deer, elk, birds, snowshoe hares, and other small mammals.

[6] Within the spruce and fir community type, trees often lose their lower branches, becoming unavailable to hare and other small mammals for food or cover during the seven to nine months of winter.

[12] The trees all grow older, close the canopy, the understory is repressed, branches fall off during the winter, and for the majority of the year there is no available food.

No patches will be left for shelter and the fir and spruce will take much longer to regenerate because of the distance from the remaining stands to the center of the burned site.