Here at DNR we often talk about trees in terms of their value for habitat as well as for revenue to state trust land beneficiaries, such as public schools, state universities, many counties, and others. Then there are the trees whose main value is for habitat and beauty. Cottonwoods fall squarely into this latter category.
Cottonwoods aren’t worth much on the timber market, they can crowd out and shade new conifer plantations, and they don’t have many BTUs of energy for firewood use. They sprout when and where they aren’t wanted and form impenetrable stands. They can clog septic drain fields. They are notorious for breaking apart during minor storms and, among other annoying habits, their billowing cottony seeds can clog water intake structures and screens. Yet, they are one of the most widespread and important wildlife trees in the western United States and Canada.
Cottonwoods belong to genus Populus. There are at least four primary species of Populus in North America: eastern cottonwood (Populus deltoides), balsam poplar (P. tacamahacca), black or western cottonwood (P. trichocarpa), and quaking or trembling aspen (P. tremuloides). Two of these–western cottonwood (also called black cottonwood) and quaking aspen–are found on appropriate sites across Washington.
Balsam poplar occurs throughout the intermountain west and is most prevalent in northern Canada and Alaska while aspen, the most widespread native poplar throughout the northern hemisphere, is unique enough for an article of its own. In this article, we will focus on the black or western cottonwood. (more…)