The Online Library of Knowledge



A trailer picks up logs from newly felled treesA trailer picks up logs from newly felled trees Wood is an important material, with many uses in the timber industry (construction and products) as well as for fuel. The world's forests are a vital renewable resource. 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. But as well as being sources of wood, forests slow down soil erosion from wind and water, and are vital wildlife habitats. They are also important absorbers of carbon dioxide, one of the greenhouse gases that contribute to global warming. Forestry is the practice of ensuring that trees are harvested sustainably—in a way that protects the future of forests. When a section, or “stand”, of forest is cut down, new seedlings are used to reforest the area.

A timber harvester in operation, FinlandA timber harvester in operation, Finland
A cross-section through a tree trunkA cross-section through a tree trunk


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 timber and as a fuel.

There are about 1 trillion tonnes of wood in the world. (A trillion is a million million, or a 1 followed by 12 zeros; 1 tonne is roughly the weight of a family car.)

© 2020 Q-files Ltd. All rights reserved. Switch to Mobile