1242 A NATIONAL PLAN FOR AMERICAN FORESTRY 



larger agricultural area unless technological developments continue 

 to increase the efficiency of production. The additional 25 to 30 

 million acres of submarginal agricultural land likely to be in need 

 of some degree of reforestation by 1950 will be offset, at least in part, 

 by further clearing of forest land, particularly in the Mississippi 

 Delta and in the West. 



Abandonment of agricultural land is the result of both physical 

 and economic causes. Loss of fertile top soil through erosion is per- 

 haps the most important of the physical factors ; others include exhaus- 

 tion of soil fertility by continued unscientific cropping, rough topogra- 

 phy, unsatisfactory climate, and the gradual encroachment of brush. 



Of the economic factors, changes in the character of agriculture itself 

 have perhaps been the most important in recent years. The decline 

 in the use of horses and mules, which makes unnecessary the use of 

 land in the production of feed for these animals, has been of tremen- 

 dous importance. In the last few decades there has also been a 

 marked increase in the efficiency of agricultural production which has 

 tended to reduce the area required. The growing use of machinery 

 in agriculture has been another important factor. It has lowered 

 costs on the level lands and forced out of production rougher lands 

 where farms are usually broken up into small units. These things 

 have followed the opening of the fertile level lands of the West, which 

 gave the initial impetus to abandonment in the East. There has 

 also been inolved, up to the last 3 years, an attraction of farm popu- 

 lation to the cities. Finally, agricultural land has sometimes been 

 forced out of production by a loss of markets, resulting from the pass- 

 ing of local industries. In the Lake States especially, the decline 

 of the lumber industry has caused the abandonment of considerable 

 areas formerly employed in supplying a local market with agricultural 

 products. 



The principal factor which may lead to a permanent shift of land 

 from forest to agriculture is an increase of population. In many 

 localities, land-colonization schemes have been important factors 

 in extending agricultural areas on cut-over forest land and such proj- 

 ects may be expected to have continued local influence. 



ANTICIPATED SHIFTS IN FOREST LAND USE AND 



OWNERSHIP 



The ownership of the present forest area as estimated in a much 

 earlier section, Forest Land, the Basic Resource, and the anticipated 

 shift in ownership as estimated in the succeeding section, The Probable 

 Future Distribution of Forest Land Ownership are shown in table 1. 

 The major shifts indicated are a substantial reduction in privately 

 owned land and a corresponding increase in public ownership. Ad- 

 justments in use which will be accomplished as a result of these shifts 

 in ownership involve a considerable increase in the areas reserved 

 from commercial timber production in order to provide adequately 

 for watershed protection and for the increasing demand for special 

 recreational areas. But the productive use of large areas now idle 

 will be by far the most important result of the indicated gain in 

 public ownership. The reasons for these changes, discussed in detail 

 in other sections of this report, may be summarized as follows: 



1. The instability of private ownership in the United States is so 

 great that in some regions it can be properly characterized as a 



