Wood is a hard tissue found in the trunks, branches and roots of trees and shrubs. Wood is made up of fibres of cellulose, the substance that forms the cell walls of all plants, bound together with lignin, the substance that gives wood its rigidity. Wood is strong, long-lasting, easily cut and burnable. These properties make wood valuable as a raw material both for products and as a fuel. Logging is the process of cutting down trees, dragging them out of the forest, then loading them up for transportation to a mill for cutting.

Uses in construction

Since humans first started to build shelters, wood has been used as a construction material, for elements such as frames, walls, floors and roofs. Wooden frames and other structural elements are still commonly used in new buildings today. Some new buildings are constructed with engineered wood, in which the wood is bound together with adhesives to make it extra strong. Wood used in this way is called timber.

Uses in products

Products commonly made from wood include paper, packaging, boats, furniture, tools and utensils (paintbrush handles, chopsticks or spoons), musical instruments and sports equipment (cricket bats or lacrosse sticks). Particular woods are carefully selected for each of these items, depending on the properties required. For example, white willow is used for cricket bats because it is light but tough.

Uses as fuel

Wood was the first source of energy, used by humans for warmth and light. Fuelwood is still widely used for cooking, heating and sometimes for running steam turbines to generate electricity. Despite the widespread use of coal and oil and the development of other sources of energy, such as nuclear and wind power, wood still provides 9% of the world’s energy. More than 2 billion people depend on wood for cooking and heating, mostly in developing nations. Unlike coal or oil, wood is a renewable energy source—as long as more trees are planted to replace those cut down.