Forest

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:

    It is as when a migrating army of mice girdles a forest of pines. The chopper fells trees from the same motive that the mouse gnaws them,—to get his living. You tell me that he has a more interesting family than the mouse. That is as it happens.
    Henry David Thoreau (1817–1862)

    Look at this poet William Carlos Williams: he is primitive and native, and his roots are in raw forest and violent places; he is word-sick and place-crazy. He admires strength, but for what? Violence! This is the cult of the frontier mind.
    Edward Dahlberg (1900–1977)

    How old the world is! I walk between two eternities.... What is my fleeting existence in comparison with that decaying rock, that valley digging its channel ever deeper, that forest that is tottering and those great masses above my head about to fall? I see the marble of tombs crumbling into dust; and yet I don’t want to die!
    Denis Diderot (1713–1784)