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:
“Instead of calling on some scholar, I paid many a visit to particular trees, of kinds which are rare in this neighborhood, standing far away in the middle of some pasture, or in the depths of a wood or swamp, or on a hilltop.... These were the shrines I visited both summer and winter.”
—Henry David Thoreau (1817–1862)
“Lock in! Be alert, my acrobat
and I will be soft wood and you the nail
and we will make fiery ovens for Jack Sprat
and you will hurl yourself into my tiny jail
and we will take a supper together and that
will be that.”
—Anne Sexton (1928–1974)
“Cats seem to go on the principle that it never does any harm to ask for what you want.”
—Joseph Wood Krutch (1893–1970)