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:

    The partridge and the rabbit are still sure to thrive, like true natives of the soil, whatever revolutions occur. If the forest is cut off, the sprouts and bushes which spring up afford them concealment, and they become more numerous than ever. That must be a poor country indeed that does not support a hare. Our woods teem with them both.
    Henry David Thoreau (1817–1862)

    I was struck by this universal spring upward of the forest evergreens.
    Henry David Thoreau (1817–1862)

    They say he is already in the forest of Arden, and a many
    merry men with him; and there they live like the old Robin
    Hood of England.
    William Shakespeare (1564–1616)