Elementary biology; an introduction to Elementary biology; an introduction to the science of life elementarybiolog00grue Year: 1924 384 ELEMENTARY BIOLOGY increasing the actual amount of growth, it is plain that the value of the growth can be increased if the trees do not have curved or twisted trunks or branches. By selecting straight-growing varieties and by concentrating the growth in the best trees (by thinning out the least desirable ones) it is possible to increase the yield of a forest area. Fig. 20I. United States forest reserves The economy of national control of forests, as well
Elementary biology; an introduction to Elementary biology; an introduction to the science of life elementarybiolog00grue Year: 1924 384 ELEMENTARY BIOLOGY increasing the actual amount of growth, it is plain that the value of the growth can be increased if the trees do not have curved or twisted trunks or branches. By selecting straight-growing varieties and by concentrating the growth in the best trees (by thinning out the least desirable ones) it is possible to increase the yield of a forest area. Fig. 20I. United States forest reserves The economy of national control of forests, as well as the protection of public interests thereby, has been strikingly demonstrated since our entrj' upon the Great War 424. Avoiding wood waste. In the national forests the lum- bermen are given a practical demonstration of the value of scientific cutting, seeding, reforesting, etc., and also of the economical handling of growth. Damage to trees often results from careless lumbering. The tree that is being cut down is sometimes damaged, and it is sometimes allowed to injure trees that are left standing. When wood was cheap, a great deal from each tree was left to rot on the ground. Now everything that can possibly be used is saved, and the remaining brush- wood is carefully burned, instead of being left under the trees as a constant fire risk.
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