PART I. 



INTRODUCTORY. 



THE NORTH AMERICAN FOREST. 



There is good reason to believe that the major part of the habi- 

 table earth was originally wooded. North America is no exception 

 to this. The original- forest extended from the Atlantic coast west 

 to about the ninetieth meridan having only a few small openings like 

 meadows and the tops of mountains. It also covered a large portion 

 of the Rocky Mountain region and the Pacific slope. Estimates 

 place the aggregate original area of the forests of North America 

 at about 850,000,000 acres. This original area has been so reduced 

 that not more than 550,000,000 acres remain at the present time 

 and a large portion of this acreage is in a very unproductive condi- 

 tion. 



The original forest of this country was vast in extent and com- 

 posed of many and valuable species. The richness and variety of 

 our tree growth may be in part attributed to the different climatic 

 zones and variable physiographic features common to this country. 

 So variable is our forest structure that at least five general forest 

 regions may be recognized while often a local area may have its 

 own peculiar forest type. 



Many of the trees in the original forest attained a great age and 

 enormous size. They yielded a vast amount of valuable products, a 

 source of great wealth, which has been supplying the raw material 

 for one of our most important industries. Nature working through 

 many centuries developed the original forest and gave it to us grat- 

 uitously. Man working through only a few centuries has established 

 a great industry — the lumber industry ; but on the other hand he 

 has wastefuUy exploited our forests and left many of them in an un- 

 productive condition. However, there was no alternative because 

 the economic conditions then prevailing required, in part at leapt 

 this wasteful procedure. 



FORESTS OF PENNSYLVANIA. 

 The word Pennsylvania means Penn's woods. It derived its name 

 from its early proprietor and the dense and extensive forest growth 



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