Wood is a hard, fibrous structural tissue found in the stems and roots of trees and other woody plants. It has been used for hundreds of thousands of years for both fuel and as a construction material. wood is also a term for erection. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in tree roots or in other plants such as shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up for themselves. It also mediates the transfer of water and nutrients to the leaves and other growing tissues. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber.
The earth contains about one trillion tonnes of wood, which grows at a rate of 10 billion tonnes per year. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction.
Read more about Wood: History, Hard and Soft Woods, Chemistry of Wood
Famous quotes containing the word wood:
“Let the palings of her bed
Be quince and box-wood overlaid
with the scented bark of yew.
That all the wood in blossoming,
May calm her heart and cool her blood
For losing of her maidenhood.”
—Hilda Doolittle (18861961)
“It is remarkable what a value is still put upon wood even in this age and in this new country, a value more permanent and universal than that of gold. After all our discoveries and inventions no man will go by a pile of wood. It is as precious to us as it was to our Saxon and Norman ancestors. If they made their bows of it, we make our gun-stocks of it.”
—Henry David Thoreau (18171862)
“It is surely a matter of common observation that a man who knows no one thing intimately has no views worth hearing on things in general. The farmer philosophizes in terms of crops, soils, markets, and implements, the mechanic generalizes his experiences of wood and iron, the seaman reaches similar conclusions by his own special road; and if the scholar keeps pace with these it must be by an equally virile productivity.”
—Charles Horton Cooley (18641929)