A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending on various cultural definitions, what is considered a forest may vary significantly in size and have different classifications according to how and of what the forest is composed. A forest is usually an area filled with trees but any tall densely packed area of vegetation may be considered a forest, even underwater vegetation such as kelp forests, or non-vegetation such as fungi, and bacteria. Tree forests cover approximately 9.4 percent of the Earth's surface (or 30 percent of total land area), though they once covered much more (about 50 percent of total land area). They function as habitats for organisms, hydrologic flow modulators, and soil conservers, constituting one of the most important aspects of the biosphere.
A typical tree forest is composed of the overstory (canopy or upper tree layer) and the understory. The understory is further subdivided into the shrub layer, herb layer, and also the moss layer and soil microbes. In some complex forests, there is also a well-defined lower tree layer. Forests are central to all human life because they provide a diverse range of resources: they store carbon, aid in regulating the planetary climate, purify water and mitigate natural hazards such as floods. Forests also contain roughly 90 percent of the world's terrestrial biodiversity.
Read more about Forest: Etymology, Distribution, Classification, Forest Loss and Management
Famous quotes containing the word forest:
“The forest of Compiegne. Look at it. Like a kind grandmother dozing in her rocking chair. Old trees practicing curtsies in the wind because they still think Louis XIV is king.”
—Billy Wilder (b. 1906)
“I perceive that in these woods the earliest settlements are, for various reasons, clustering about the lakes, but partly, I think, for the sake of the neighborhood as the oldest clearings. They are forest schools already established,—great centres of light.”
—Henry David Thoreau (1817–1862)
“A favorite of outdoor alcoholics, connoisseurs and Fundamentalists, these pills turn water into wine. In 10 minutes the most fetid swamp scum in the forest can become modest red, elusive and light on first taste, yet playful—one might say a trifle impudent—on the afterbite. Saves pack space by eliminating need for bulky corkscrew, decanter and bottles. Store pills on their sides in a cool dark place.”
—Alfred Gingold, U.S. humorist. Items From Our Catalogue, “Wine Pills,” Avon Books (1982)