FORESTS The world production and consumption of wood amounts to approximately 56,000,000,000 cu.ft., which is an average of 32 cu.ft. per caput. About 26,000,000,00o ft. is saw-timber, and 30, 000,000,000 ft. is firewood.
As populations grow and as living standards rise and human wants become more complex, timber consumption increases, in spite of the extensive and growing use of substitute materials, and in spite of the tendency to utilize wood more economically.
In Great Britain timber consumption has increased much more rapidly than has the population. Even in France with a practi cally stationary population, timber consumption was slowly in creasing until 1914; that of Germany more than doubled within the century; in the United States at least four times as much lumber is (1937) used as in 185o. Judging from the rates of in crease in these and other important consuming countries, the world's timber needs may be expected to double within approxi mately 5o years. The per caput consumption in North America of saw-timber (177 cu.ft.) is five times as great as that of Europe, and if the tropical countries south of the United States be dis regarded, it is six and one-half times that of Europe. Europe, South America and Australia use about equal amounts of wood per caput (39 cu.ft.). The proportion of saw-timber to total amount of wood used, however, is quite different, being only one ninth in South America, two-fifths in Australia and over one-half in Europe. Asia and Africa use comparatively small amounts of wood (9 and 5 cu.ft. respectively).
The total quantity of wood grown in the world each year is roughly estimated at about 38,000,000,000 cubic feet. If this increment were spread evenly over the whole forest area, it would amount to only 5.1 cu.ft. per acre. It is apparent that the pres ent annual growth of 38,000,000,000 cu.ft. is not replacing the present annual cut of 56,000,0oo,000 cubic feet. The amount of growth each year represents the growth of only a small part of the forest. Vast areas of virgin forests must be left out of the calcu lation, because in their present condition there is no net growth in them. If all the forests of the world were placed in a growing condition, with a moderate amount of management and protec tion against devastation, they could produce annually at least 355,000,000,00o cu.ft. of wood, or nearly so cu.ft. per acre.
With about 7,500,000,00o ac. of productive forest area in the world, bearing heavy stands of virgin timber, having possible growth many times the world's present timber requirements, it would seem that there is enough timber to last for centuries. This would be true if all kinds of wood were equally capable of satisfying human wants. There are about 2,645,000,00o ac. of softwoods or conifer forests in the world; some 1,204,000,000 ac. of temperate hardwoods or broad leaf forests, and 3,638,000,00o ac. of tropical hardwoods. Although the softwoods and temperate hardwood forests together form only one-half of the total forest area of the world, 91% of all the timber cut and used comes from the softwood and tem perate hardwood forests of the Northern Hemisphere, and only 9% from the tropical hardwoods. The softwood forests are furnishing three-fourths and the temperate hardwoods one-fifth of the construction timber of the world. The temperate hard woods, in addition, supply three-fourths of all the firewood. The amount of standing timber in the tropics is far greater than the amount remaining in the temperate regions, yet until recently, the tropical forests have played a minor part in supplying the world's timber. There has been prevalent an idea that the tropical forests are composed chiefly of cabinet woods, dyewoods and similar kinds of hard, heavy, deeply coloured wood, suitable for furniture and special uses, but not for construction. Recent explorations have shown that there are many excellent construc tion woods, equal if not superior to the woods of conifers for use in the tropics because more resistant to decay and termites. Before the tropical forests are able to supply a large part of the world's requirements there must be developed adequate systems of cheap transportation and adequate supplies of efficient labour. Another difficulty is that the tropical forests are mostly composed of a variety of species, intermingled in the greatest confusion, and can be exploited economically only if practically all the important species can be utilized. The crux of the world's timber supply problem, during the next two or three generations at least, lies in the available supplies of softwood and temperate hardwood.