Economic And Ecological Importance Of Spruces
Spruces are commonly harvested for use in the manufacturing of pulp, paper, and cardboard. Spruces are excellent raw material for these uses because their light-colored wood has relatively long and straight fibers. In addition, the cellulose concentration of the wood is high, while the concentrations of tannins, gums, resins, and other waste components are relatively small.
Spruce logs are also sawn into lumber and other wood products and used to build structures, furniture, and other value-added products. Larger spruce logs may also be used to manufacture plywood and other composite materials.
These uses of spruces in the forest industries are very important economically throughout the range of these trees in the Northern Hemisphere and elsewhere. Depending on the local ecological conditions and the type of forestry being practiced, the post-harvest regeneration may rely on small spruce plants that were present before the harvest, on seedlings that establish naturally afterwards, or on seedlings that are deliberately planted. Subsequent management of spruce plantations may include the use of herbicides to reduce the competition from weeds, and thereby increase the growth rate of the economically valued spruce trees. The plantation may also be thinned to achieve optimal spacing, and insecticides may be sprayed if there is an epidemic of a significantly damaging insect.
A relatively minor use of spruce bark is for the commercial extraction of tannins, chemicals useful in the tanning of raw animal skins into leather. Sometimes, spruce gum, especially of red spruce, is collected and used as a chewing gum with a pleasant, resinous taste. The spruce gum must be properly aged for this particular usage.
Spruces are also commonly used for horticultural purposes. In North America, use is most frequently made of native white spruce, red spruce, and blue spruce, a species that is particularly attractive because of its glaucous, bluish foliage. The Norway spruce of Europe and tigertail spruce (P. polita) of China are also widely planted as ornamentals in North America.
In the winter, spruce trees are commonly harvested for use as Christmas trees. They do well for this purpose, although they tend to shed their leaves if they are kept in a warm, dry, indoor environment for too long.
Many species of resident and migratory wildlife require spruce-dominated forests as their critical habitat for breeding or other purposes. Spruces are important because they provide habitat for these species of plant and animal wildlife over great regions of the Northern Hemisphere
Because they are the dominant trees of many types of forests, spruces also confer a major element of the aesthetics of many remote landscapes. This is a major service of spruces because of the increasingly important economic impact of outdoor recreation and ecotourism.
See also Pesticides.