Willow Family (Salicaceae)
Economic And Ecological Importance Of Willows
Many species of willows are important ecologically. Willows are often species of early succession, and they are important in the early and middle stages of successional recovery after disturbance. Willows are commonly an important browse of mammals such as deer, moose, rabbits, hares, and other species, especially during the winter when herbaceous forage is not very available.
Tree-sized willows are sometimes used for lumber. The black willow is the only species used much for this purpose in North America. Because its wood is not very strong, it is generally used to manufacture boxes and similar goods.
Because willows can be so productive, there has been research into the cultivation of tree-sized willows in
plantations for use as a biomass fuel. This use of willows as a source of renewable energy may prove to be important in the future. The willow biomass can be burned directly, or it can be chemically converted into more easily portable liquid fuels such as alcohol or a synthetic, petroleum-like mixture which can be manufactured under heat and pressure.
Because willows grow quickly and are so easy to propagate using stem cuttings, they are often used to vegetate stream banks to help prevent erosion and sometimes to re-vegetate other types of disturbed lands.
Willows have long had some use in folk medicine. Many cultures are known to have chewed willow twigs to relieve pain and fever. The original source from which salicylic acid was extracted was the bark of the white willow (S. alba) of Europe. This chemical is used to manufacture acetylsalicylic acid or ASA (sometimes known as aspirin), an economically important analgesic useful for treating pain, fever, and inflammation.
Willows may be an important source of nectar for bees in the early spring, a time when few other species of insect-pollinated plants are flowering. Willow honey may be a locally significant product in some areas.
Willow twigs are rather flexible and have been used to weave baskets, for caning, and to make woven fences and other lattices.
Some species of willows have good aesthetics and are utilized in horticulture. One of the best known species for this purpose is the weeping willow (Salix babylonica), a beautiful, pendulous tree. This species is native to northern China. However, the weeping willow was considered to be so beautiful by the famous Swedish botanist Carl von Linnaeus, who gave the species its scientific name, that he decided that it must have been present in the biblical Garden of Babylon; hence, the origin of the geographically inaccurate, scientific binomial of the weeping willow.
The weeping willow has been widely introduced to North America as an ornamental tree. Other non-native species that are commonly used in horticulture include the crack willow (S. fragilis) of Eurasia and the white willow (S. alba) and basket willow (S. viminalis) of Europe. Some of these species have escaped from cultivation and have become locally invasive in natural habitats.
Wild willows also have pleasant aesthetics. Most famous in this sense are the several species known as "pussy willows," especially the pussy willow (Salix discolor). These species produce large, attractive catkins in the early springtime. In fact, stems of these species can be collected in the late winter before they have bloomed and placed in water in a vase. In a short time, the pussy-willow stems will bloom indoors to pleasantly herald the arrival of spring.
Judd, Walter S., Christopher Campbell, Elizabeth A. Kellogg, Michael J. Donoghue, and Peter Stevens. Plant Systematics: A Phylogenetic Approach. 2nd ed. with CD-ROM. Suderland, MD: Sinauer, 2002.
Klein, R.M. The Green World. An Introduction to Plants and People. New York: Harper and Row, 1987.