1490 A NATIONAL PLAN FOR AMERICAN FORESTRY 



referred to, "Watershed and Related Forest Influences". Successful 

 forestation results in the development of conditions which are far 

 more favorable to ground-water storage than the conditions which 

 exist on denuded or on cultivated land. 



The experiments of Lowdermilk previously cited show that denuda- 

 tion by fire on plots in California increased run-off to 15 or 20 times 

 that of adjacent undisturbed areas. Studies by the Lake States 

 Forest Experiment Station have shown that the average maximum 

 run-off from slopes in Wisconsin is nearly 10 tunes as large from 

 cornfields and fallow ground as from the forest. In northern Mis- 

 sissippi, experiments previously referred to under erosion showed that 

 the plots in a planted forest had a run-off that was less than 5 percent 

 of a 12-inch rainfall, whereas plots on an abandoned field and culti- 

 vated land showed a run-off that was 44 to 48 percent of the same 

 precipitation. 



The superior ability of forest areas to absorb precipitation over 

 that of denuded areas is due partly to the litter cover and partly to 

 the condition of the soil itself. Studies by Auten in the Central 

 States have shown that field soils when planted to forest will increase 

 their capacity to absorb water eightfold in 20 years. 



Plantations, therefore, are effective not only in controlling erosion 

 and permitting better percolation into the soil but actually, on 

 abandoned fields, in causing the absorptive capacity of the surface 

 soil layers to increase greatly. 



INCREASE IN TIMBER PRODUCTION 



The section of this report entitled "The Present and Potential 

 Timber Resources" indicates that saw-timber and cordwopd produc- 

 tion must be increased by more than 7 billion cubic feet in order to 

 meet requirements at the present rate. This increase will be fur- 

 nished in part by better protection of existing forests from fire, insects, 

 and disease; and in part by more intensive management of the forests. 

 A part of this deficit should be met by increasing the area of produc- 

 tive forest land through the planting of devastated areas or non- 

 stocked abandoned farm land, or both. All three means should be 

 undertaken simultaneously. 



It is only fair to state at the outset that private interests, unaided, 

 have at present little assurance of direct financial profit from large- 

 scale plantings on barren lands. When unsupported by other areas 

 of land bearing merchantable or near merchantable timber such 

 plantings, on reaching merchantability, may have built up such 

 charges in the form of planting costs, taxes, protection, and interest 

 that they not always resolve into a profitable business for the private 

 owner. Individual analysis of each situation is necessary to deter- 

 mine the financial soundness of planting. 



In contrast, many wood-using operators own productive forest 

 properties whose yield is inadequate ^to supply the full amount of 

 timber necessary for permanent capacity output. Forest planting on 

 barren or poorly stocked parts of their properties will increase their 

 timber production and may make them independent of outside sup- 

 plies, round out their properties, and hence protect the investment in 

 manufacturing plants and improvements. The enlarged plant output 

 thus made possible may increase the profit from the whole property 



