PART I. PRODUCTION OF TIMBER : , ; /. 



CHAPTER I. TIMBER TREES 

 Sedlion 1. Roots, Stem and Foliage. 



1. For the purpose of study a tree may be divided into 

 three parts; roots, stem, and foliage. 



2. The roots penetrate the soil and give the tree a base 

 to stand on. They also absorb water and other substances 

 which the tree needs in its life-processes. The absorbing 

 surface of the roots is increased by throwing out root-hairs. 

 These are not rootlets, but are outgrowths from the roots 

 and rootlets. They live for a few days and then die away: 

 others are thrown out as needed. 



3. The stem and branches lift the foliage from the 

 ground and expose it to the light and air; and it is through 

 them that water and other substances (in solution) pass from 

 the roots to the foliage. The stem grows in diameter and 

 height by the addition of new wood. In most trees the old wood 

 can be distinguished from the new; and the age of the tree 

 can be found by counting the annual layers. The stem may 

 be likened to a set of cones, one fitting over the other. The 

 growth of the branches is like the stem; and as they 

 grow outward they become larger: when they die and are 

 broken off the wood closes over them. Branches make knots 

 in lumber, and the kind of knots influences the quality of the 

 lumber: they will be referred to again. 



4. The foliage of a tree is its kitchen; for there is 

 where its food is prepared. Water and other substances 

 from the soil and carbon dioxide (C02) from the air are brok- 

 en up in the leaves in the presence of light, and are made 

 into compounds that are used by the tree in building up its 



