30 The Farm Woodlot 



autumn, it is called deciduous. Even the evergreens do 

 not keep the same leaves all the time ; they are only called 

 evergreens because they never lose all their leaves at the 

 same time. The white pine needles remain on the trees 

 from two to four years, the red cedar seven or eight and the 

 other evergreens range between these two. In falling, 

 they give back to the soil chemicals that the tree has 

 drawn from it, and more besides. It is this which causes 

 the continued growth of forest on a piece of land to increase 

 the fertility of the soil. 



The roots supply most of the raw material with which 

 the leaves work. They are underground branches spe- 

 cially adapted to absorb moisture from the soil. 



Some trees, such as the oaks, hickories, walnuts and 

 some of the pines, have practically only one root, a large 

 one called a tap-root, running straight down into the 

 ground. This is an inherited quality and cannot be modi- 

 fied very much by a change in the environment. 



Others, such as the spruce, tamarack and balsam, have a 

 lateral system of roots which lie on or very near the sur- 

 face of the ground, while still others, like ourmaples, ashes 

 and elms, have a combination of the two, or a mixed system. 

 These are a little better able to change and adapt them- 

 selves to new conditions. 



These roots, by reason of very fine rootlets, or root hairs, 

 suck up water from the soil and in solution with it certain 

 small quantities of lime, magnesia and potash, the raw 

 materials for plant-food. This water passes through the 

 roots, up the stem of the tree and out the branches to 

 the leaves. Here the excess water evaporates through the 

 pores, and the leaves work up the mineral salts and the 



