660 JOURNAL OF FORESTRY 



replacement of trucks, is between $1.50 and $1.80 per thousand. This 

 is somewhat higher than the cost might be under continuous railroad 

 operation, but is less than one-third of the cost of team haulage at the 

 present time. Moreover, it pemiits intermittent operation without 

 serious depreciation in the investment or material increase in cost of 

 hauling. It further means that the unit of logging operations need not 

 be a single body, but may be a number of bodies of timber reached by 

 convenient roads. It implies an entire readjustment of our concept of 

 a logging unit. As employed by the operation just mentioned, trucks 

 are also performing excellent work in logging whenever the weather 

 and road conditions are such as to permit hauling on special woods 

 roads constructed at a cost of about $300 per mile. A truck is loaded 

 with logs and makes the trip of a mile and return within less than an 

 hour, a 7-ton truck being able to deliver about 20,000 feet of logs a 

 day. Caterpillar tractors especially meet the conditions. 



Many of the conditions in the Appalachians are particularly favor- 

 able to the employment of autotrucks. The mixture of timber is not 

 tmiform over the mountains, but is concentrated in the deep coves or 

 narrow valleys in which roads are located or must be located. The 

 deeply dissected terrain results in three conditions of site and forest: 

 ( I ) the drainage lines or coves which afford the best facilities for tree 

 growth and contain stands of the best quality; (2) the slopes well 

 timbered wnth species of medium value; and (3) the dry upper south 

 sides and ridges deficient in moisture and lightly timbered. 



Considering the region from Pennsylvania south to Alabama as a 

 whole, less than 10 per cent of the area is in coves with stands of a 

 heaviness represented by 10, about 70 per cent of the surface is on the 

 slopes with stands of a heaviness of 4, and about 15 per cent along dry 

 south slopes, ridges, and crests, with stands of a heaviness of i, while 

 5 per cent is nonproductive. At the present time the relative unit value 

 of the timber in these stands is respectively 5, 3, and 2 ; so that the per- 

 acre value is in the relation of 50 for cove, 12 for slopes, and 2 for 

 ridges. Consequently more than one-third of the total timber value is 

 on one-tenth of the area and somewhat less than four-fifths is on about 

 one-half of the area. This necessitates comparatively few roads to 

 penetrate the greater portion of the timber-producing land. 



The road systems of the Appalachian Forests should be designed 

 primarily for developing the forests by truck service, with larger log- 

 ging units than circular mills demand. Many heavily timbered tracts 

 which otherwise would be operated by logging railroad or by flume can 



