THE FOREST 29 



thrusting its way above a lower story of birch and poplar. 

 Gradually the higher trees deprive this lower story of light. 

 The stand of poplar and birch is being crowded out and will 

 soon be gone. A little later, the pines, maples, and oaks sow 

 their own seeds over the area and in the next tree generation 

 they will have crowded out all other species. Once again nature 

 has brought back the same forest that grew there before the 

 days of the cutting and burning. 



Long and roundabout is this process of restoring the original 

 forest trees after destructive cutting and heavy fires. Sometimes 

 it is centuries before replacement is complete. In parts of the 

 Adirondacks where fires have burned not only the trees but 

 destroyed the soil itself many hundreds of years will pass before 

 trees of any kind can grow there. 



When undisturbed by man or fire, nature works constantly 

 toward the perpetuation of certain forest types. These are called 

 climax types, for they represent the type of forest best fitted 

 to survive in that particular place. Although this climax type 

 changes with the region, with altitude, and often with the soil, 

 it is the ultimate type that nature will grow in that particular 

 environment. Even on opposite sides of the same hill we may 

 find different types of climax forest. In some regions it may be 

 our mixture of pine, oak and maple. In others a mixture of 

 white and red pine and in still others, as over a great portion 

 of the west, yellow pine alone is the climax type. 



But for each locality and soil type, there is a species or com- 

 bination of species that does best there the so called climax 

 type. Toward this type nature is constantly working. Man or 

 fire may for a time overthrow nature's purpose and other trees 

 may come in and temporarily seize the soil, but gradually if 



