Western Washington’s Sitka spruce is not afraid to stand out from the rest. This tree can be seen sporting a variety of forms, from bizarrely shaped root systems to huge buttresses. Its unique shape has a lot to do with growing in a coastal environment. Being near the water, Sitka spruce faces challenges that inland trees don’t, such as a dense forest floor and extreme elements. These challenges force the tree to bend and twist in irregular ways.
How exactly does the forest floor of the coast affect the shape of Sitka spruce? The moist floor is often thick with bryophytes and other plants which makes it challenging for a tiny seed to grow. Therefore, Sitka spruce prefers to grow on elevated organic surfaces, such as logs and stumps. When these logs decay and disappear, the resulting Sitka spruce can display an oddly shaped root system and huge buttresses.
Another factor that contributes to the individuality of Sitka spruce is its exposure to coastal elements. Violent winds can alter the shape of a Sitka spruce and if the tree’s top is rotten, the winds might even cause it to snap off.
Interesting facts like this and more can be found in DNR’s guides for identifying old trees and forests in Washington: Identifying Mature and Old Forests in Western Washington and Identifying Old Trees and Forests in Eastern Washington, both written by Robert Van Pelt, PhD. Both guidebooks are free to download.
Conservation of old-growth and other “structurally unique” trees is part of the State Trust Lands Habitat Conservation Plan that DNR uses to guide its management of working forests and provide habitat for endangered species on state trust lands.