1530 A NATIONAL PLAN FOR AMERICAN FORESTRY 



destruction of the forest by fire. Erosion, therefore, is not serious 

 except in restricted local areas. 



A large part of the white pine and Douglas fir forests is in private 

 ownership and in general is being liquidated through exploitation as 

 rapidly as possible. Apparently part of these lands will ultimately 

 return to public ownership. Cutting on private land has not been 

 designed to maintain watershed values, and this condition, coupled 

 with the common occurrence of fire following logging, has markedly 

 reduced the effectiveness of these forests in stream-flow regulation. 



These dense forests are exceptionally productive, and therefore 

 would justify intensive management for timber production. The 

 correction of cutting practice and the improvement of fire protec- 

 tion to meet even minimum requirements for timber production 

 would adequately protect watershed values involved. Certainly 

 these two measures are justified. 



PONDEROSA PINE-LODGEPOLE PINE BELT 



The broad classification ponderosa pine-lodgepole pine belt in- 

 cludes the greater part of the commercial and subalpine forests of 

 the West, excluding, of course, the more dense forests of the Pacific 

 slope previously discussed. It includes the ponderosa pine forest 

 with its various mixtures, the extensive lodgepole pine forests, the 

 Rocky Mountain Douglas fir and spruce-fir forests, and the sub- 

 alpine mixtures usually found above the commercial timber zone. 

 The influences exerted on watershed conditions by the different 

 forest types in this usually more arid belt are essentially similar. 



Within this belt most of the precipitation comes in the form of 

 snow, so that to the other run-off regulating influences of the forest 

 is added retardation of snow melt. In contrast with conditions in 

 the dense forests of the Pacific slope, the vegetative cover if once 

 destroyed is likely to be slow in reclothing the soil, a condition that, 

 as previously stated, favors accelerated erosion and run-off. The 

 greater part of the area is used as range for livestock. This use easily 

 upsets the vegetative balance, thus seriously reducing the effective- 

 ness of the watershed cover. (Complete exclusion of livestock, 

 however, is usually neither necessary nor desirable.) 



These forests are the source of the greater part of the water flow 

 for irrigation, water power, and domestic and industrial use in the 

 West. Streams originating in them are, to a great extent, depended 

 upon for the irrigation of nearly 20 million acres of land on irrigated 

 farms which are valued including all land, buildings, and equipment 

 at $4,887,000,000; for water-power developments that on January 1, 

 1931, were estimated to have an installed capacity of nearly 5 million 

 horsepower or about 32 percent of the total installed capacity in the 

 United States; and for industrial and domestic water supplies for 

 about 6 million people. It is not an overstatement to say that the 

 economic existence of the West is the measure of the importance of 

 these waters. 



Fortunately a very high percentage of the area is in national 

 forests, national parks, and Indian reservations, where, as has been 

 stated, something approaching proper watershed management is 

 provided. Perhaps 3 million acres of it is in the public domain, 

 where no management is provided other than inadequate fire pro- 

 tection and where watershed conditions are extremely bad. 



