38 MISC. PUBLICATION 217, U. S. DEPT. OF AGRICULTUEE 



Forest types may be compared to the make-up of various associ- 

 ations of people within a large city where, over rather extensive areas, 

 one or different races predominate, either as a single race or, as often 

 happens, two or more compatible races that are able to cooperate or 

 supplement each other in making the best of existing conditions. 

 The forest types that prevail over extensive areas have been defined 

 and named by the one or more dominating kind or species of trees 

 and have come to be well known. Such, for example, are the spruce- 

 fir and the birch-beech-maple types within the northern forest region, 

 and the Douglas fir and sugar pine-ponderosa pine types of the Pacific 

 coast forest region as shown below. 



Forest types corn-posing each of the six forest regions of continental United States 16 



Northern: Acres 



Pines 14, 487, 000 



Spruces and firs 29, 908, 000 



Aspen 21, 688, 000 



Birch-beech-maples 17, 118, 000 



Total 83,201,000 



Central hardwood: 



Oaks-hickories 44, 342, 000 



Oaks-pines 35, 575, 000 



Oaks-chestnut-yellow poplar 52, 459, 000 



Total 132,376,000 



Southern: 



Southern pines (8 species) 126, 027, 000 



Cypress-southern hardwoods 23, 412, 000 



Total 149,439,000 



Tropical: 



Mixed hardwoods (tropical) 400, 000 



Total 400,000 



Rocky Mountain: 



Ponderosa pine 21, 811, 000 



Western white pine-western larch 12, 984, 000 



Lodgepole pine 16, 541, 000 



Spruces-firs 11, 563, 000 



Total 62,899,000 



Pacific coast: 



Douglas fir 27, 687; 000 



Ponderosa pine 25, 070, 000 



Sugar pine-ponderosa pine 10, 183, 000 



Western white pine-western larch 669, 000 



Spruces-firs 1, 532, 000 



Coast redwood-bigtree 1, 544, 000 



Total 66,685,000 



United States 495,000,000 



is Does not include Alaska, Puerto Rico, and Hawaii (figs. 8, 9, and 10). (See fig. 7.) 



