Ī 2011 discovery in the Canadian province of New Brunswick yielded the earliest known plants to have grown wood, approximately 395 to 400 million years ago.
Dominant uses were for furniture and building construction. In 1991 approximately 3.5 billion cubic meters of wood were harvested. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. More recently it emerged as a feedstock for the production of purified cellulose and its derivatives, such as cellophane and cellulose acetate.Īs of 2005, the growing stock of forests worldwide was about 434 billion cubic meters, 47% of which was commercial. Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or woodchips or fiber. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. 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 the roots of trees or shrubs. It is an organic material – a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants.
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