<P> Wood has traditionally been used for fuel, especially in rural areas . In less developed nations it may be the only fuel available and collecting firewood is often a time consuming task as it becomes necessary to travel further and further afield in the search for fuel . It is often burned inefficiently on an open fire . In more developed countries other fuels are available and burning wood is a choice rather than a necessity . Modern wood - burning stoves are very fuel efficient and new products such as wood pellets are available to burn . </P> <P> Charcoal can be made by slow pyrolysis of wood by heating it in the absence of air in a kiln . The carefully stacked branches, often oak, are burned with a very limited amount of air . The process of converting them into charcoal takes about fifteen hours . Charcoal is used as a fuel in barbecues and by blacksmiths and has many industrial and other uses . </P> <P> Wood smoke can be used to preserve food . In the hot smoking process the food is exposed to smoke and heat in a controlled environment . The food is ready to eat when the process is complete, having been tenderised and flavoured by the smoke it has absorbed . In the cold process, the temperature is not allowed to rise above 100 ° F (38 ° C). The flavour of the food is enhanced but raw food requires further cooking . If it is to be preserved, meat should be cured before cold smoking . </P> <P> Timber, "trees that are grown in order to produce wood" is cut into lumber (sawn wood) for use in construction . Wood has been an important, easily available material for construction since humans started building shelters . Engineered wood products are available which bind the particles, fibres or veneers of wood together with adhesives to form composite materials . Plastics have taken over from wood for some traditional uses . </P>

Which tree contains more wood than any tree in the world