FOREST INFLUENCES 



the ground and must deal with. This committee recognized 97 differ- 

 ent types in the eastern part of the United States. Each type must 

 occupy in the aggregate hundreds of thousands of acres and must be 

 distinctive and easily separated from other cover types. Species form 

 the basis of type names rather than location, age, site, or moisture. 



Forest types may be constantly undergoing certain fundamental 

 changes. Artificial exigencies, such as burning, logging, and land 

 clearing for agriculture, interrupt the natural forces of nature. These 



Southern Bottom 

 Land Hardwoods 



FIG. 32. Distribution of forest types of the South. (After U. S. Forest Service.) 



disturbances have a considerable effect upon the development and 

 output of forest types. Climax types are those which are recognized 

 by the forester as the type which is most suitable and natural for a 

 given site. It is commonly believed that natural forces should pre- 

 vail in the culture and development of forest types. For this reason, 

 native rather than exotic species are generally favored in planting. 

 The study of ecology of forest types has occupied the attention of 

 many foresters. In the cutting of mixed hardwoods and softwoods of 

 the Northeast, the native white pine and spruce have generally been 

 the more valuable; therefore, they have been cut first. This un- 



