Figure 2.1 



Forest and Range Land Areas in the Contiguous United States 



Medium - Mixed Forest, Range, and 

 Cropland 



Darl< - Cropland, Irrigated and 



Urban 



based on vegetation. Closely related plant communi- 

 ties have been aggregated into single ecosystems. 

 Forest ecosystems are synonymous with forest cover 

 types developed and defined in the Forest Survey 

 conducted by the Forest Service.' Rangeland ecosys- 

 tems are based on potential natural plant communi- 

 ties termed phytocoenoses.- Detailed descriptions of 

 each ecosystem can be found in "Vegetation and 

 Environmental Features of Forest and Range Eco- 

 systems. "^ 



' U.S. Department of Agriculture, Forest Service Geographic 

 forest types used in the forest survey. For. Serv. Handbk. 481.^.1. 

 sec. 74, March 1967. 



- Kuchler, A. W. Potential natural vegetation of the contermi- 

 nous United States. Am. Geogr. Soc. Spec. publ. no. 36. 116 p. 

 with map. 1964. 



Kuchler. A. W. Potential natural vegetation. Nat. .Atlas of the 

 U.S.A., U.S. Dep. of the Interior, Geol. Survey, p. 89-92. 1970. 



'Garrison, George A.. Ardell J. Bjugstad. Don A. Duncan. 

 Mont E. Lewis, and Dixie R. Smith. Vegetation and environmental 

 features of forest and range ecosystems. U.S. Department of Agri- 

 culture, Agric. Handbk. 475, 68 p. 1977. 



Trends in Area 



The available data indicate that the area in forest 

 and range land has been declining in recent decades. 

 The inland water area, on the other hand, has been 

 increasing mainly due to reservoir construction. 

 These trends are expected to continue. For example, 

 the total area of forest and range land is projected to 

 be about 5 percent lower by 2030, with decreases of 

 2 percent for forest lands (from 736 to 718 million 

 acres) and 7 percent for rangelands (from 820 to 764 

 million acres) (table 2.2). 



During the 1980's, a significant portion of the pro- 

 jected decline in forest area is expected to result from 

 conversion of forest to cropland, particularly on del- 

 tas and bottomlands of southern rivers. However, 

 after 1990. reduction in forest land area will mainly 

 result from conversion to other land uses such as 

 reservoirs, urban expansion, highway and airport 

 construction, and surface mining. As indicated in the 



14 



