CHAPTER II 

 THE TREE 



In order to manage a woodlot intelligently and successfully 

 it is necessary first to know something about the life and 

 structure of trees, and also to understand something of the 

 factors that influence their growth and development. 



Trees are living organisms, that is, they carry on certain 

 life processes such as breathing, transpiration, digestion and 

 assimilation of food material. They are the highest type 

 of vegetation found on the earth, that is, they have the most 

 complex structure and life history of any plant growth. Trees 

 differ from herbs in having woody structure and perennial life 

 and from shrubs in developing single stems that elevate the 

 crowns above other forms of vegetation. 



THE PARTS OF A TREE AND THEIR USES 



The Roots. — A tree is made up of three main parts — roots, 

 stem and crown. The root system of a tree is composed of 

 larger and smaller roots, each serving a definite purpose. 

 They may be compared in form to the large and small branches 

 in the crown. The large roots tend to hold the tree firmly in 

 the ground and prevent its being blown over by the wind. 

 They conduct water and salts absorbed from the soil b)' the 

 smaller roots. These substances are absorbed by root hairs 

 that grow near the ends of the roots. As the roots grow and 

 force their way through the soil the root hairs die and are 

 replaced by new ones formed nearer the tips of the growing 

 roots. It is through these small root hairs, far out from the 

 stem of a tree, often beyond the ends of the branches, that a 

 tree takes in most of its food from the soil. 



10 



