Renewable Natural Resource — Wood
Wood is the hard, fibrous tissue
that comprises the major part of stems, branches and roots of trees belongings to the plant groups known as the gymnosperms and the dicotyledonous angiosperms. Its function in living trees is to transport liquids, provide mechanical support, store food and produce secretions.
Woods are classified as either hardwoods or soft woods, the distinction is botanical and is reflected in details of wood structure. Most (but not all) softwoods are needle-bearing evergreen trees, whereas the hardwoods are broad-leaved trees. `
The progress of humanity from the primitive state
to the present day’s highly advanced technology has been closely associated with dependence on wood. The relative case of working it and its almost universal availability have made wood as an essential material for human survival. Wood has been used for shelter, fuel, weapons, and tools since prehistoric times. As technology developed, wood came to be used for boats, vehicles and bridges.
The annual world production of wood
is about 2.4×109t used as industrial round wood (e.g. saw logs. Veneer logs, poles and pilings, and pulpwood) and the remainder (about 53%) used as fuel wood and charcoal. Developed and developing countries differ sharply in the ratio of industrial round wood to fuel wood and charcoal is, on average 18% of total wood production, in developing countries, it is 80%. In recent years, as energy sources other than petroleum have received increased attention, considerable interest has developed in the use of wood not only as a fuel directly but also as raw materials for the production of alcohol and similar sources of energy. The forest products industry is in a unique position to use its own wood residue for generation at least part of its energy needs, and is already extensively taking advantage of this possibility. How far the use of wood as an energy source scan be developed will depend on economic factors. As the technology for manufacturing wood and wood-based materials continues to develop, the tendency is for a reduction of wood residue in manufacturing operations, which will ultimately affect the availability of such residue in the factories.
The world production of industrial round wood
is of the same order of magnitude (by weight) as the production of steel and iron. Unlike steel, however, wood represent a renewable resources that can be (and is) constantly replenished as it is being used. As long as the rate of removal does not exceed the rate of growth, forests will be perpetual sources of wood and lumber. The composition of the forest with respect to tree species may change, as May the size of trees at the time of harvesting, but under proper management the resource will always be there. Increasing the intensity of management (tree farming) can lead to substantial increases in productivity on a given area of forest land.