154 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



(G) How much and to wliat extent tlie forest cover contributes to 

 regulate the amount of precipitation over a given area or the flow of 

 water tlirough a given period of time, so as to prevent or ameliorate 

 floods and droughts, in ox^position to disturbing causes, cosmic or pro- 

 duced by human agency, cannot yet be stated, though the existence 

 of such influence is sufliciently proved. 



C. — Effects of deforestation on the condition of the soil. 



(1) In the mountains deforestation causes torrents, carrying debris 

 into the valleys; land-slides, snow-slides, and avalanches are induced 

 more or less, according to the profile and nature of the rocks. 



(8) On light sandy soil, especially near the coast, where winds are 

 strongest, the shifting of sands and formation of dunes is facilitated. 



The importance of considering these influences is greatest for the 

 western half of the United States, especially for the exposed prairie 

 regions and the arid and semi-arid districts, which depend largely for 

 their agricultural develoi^ment on the water supply from the adjacent 

 mountains, and also in Southern California and in the Rocky Mount- 

 ain States and Territories. 



Common interest and the simplest prudence demand the preserva- 

 tion of these mountain forests in perpetuity under most conservative 

 management. 



Less urgent, but not to be underestimated, is the weight of these 

 considerations for the eastern half of the country, notably the coast 

 lines and the Alleghany Mountain ranges. 



condition of forest supplies and forestry in the united 



STATES. 



The forest area of the whole United States, excepting Alaska, at 

 the present time has been reported by the Forestry Division as less 

 than 500,000,000 acres (489,280,000). 



There is reason to believe that much of this area is waste brush- 

 land, and that even the timber forest often hardly deserves the name, 

 being only thinly stocked with trees. 



Leaving out of consideration the forests of the Pacific slope, esti- 

 mated at 60,000,000 acres, and said, though little knov/n, to cut large 

 amounts per acre, the balance of forest land in the United States, it 

 is believed, cannot long meet the enormous demands on its resources. 



No reliable statistics exist from which the stock on hand could be 

 even approximately computed for the whole extent; but we do know 

 tolerably well the quantity of lumber and wood annually used or re- 

 quired by our present population. In round numbers this amounts to 

 something like 20,000,000,000 cubic feet, made up of the following 

 items: 



Cubic feet. 



Lumber market and manufactures *2, 500, 000, 000 



Railroad construction f 360, 000, 000 



Charcoal ■ • 250, 000, 000 



Fences i 500, 000, 000 



Fuel , §17, 500, 000, 000 



* Computed from figures of the Bureau of Statistics. 



+ Latest estimates of the Forestry Division. 



i Computed on the basis of a careful investigation by the Department in 1871. 



^ Computed on the basis of census statistics of 1880. 



