A similar approach can be demonstrated for our conditions by a simple exercise. 

 On an average slope of 50 percent, a 12-foot road would require an additional 9 feet 

 for cut and fill. Planting at the toe of the fill and 3 feet above the cut bank would 

 result in a nonstocked width of 24 feet. Assuming 400 feet between roads and a 12-by-l 

 spacing we would lose only one row out of 33 for each road, or only 3 percent . Addi- 

 tional growth below the road would further reduce the loss of productive area. Thus, 

 the loss becomes insignificant in relation to the improved accessibility for protection 

 and management. 



The small loss in total stand production (1.4 percent) shown by this study is 

 comparable with that found in Germany for roads of similar width. Kramer (1958) 

 reported no volume reduction in Norway spruce roadside strips for roads less than 16.4 

 feet wide and only about 7 percent reduction in volume of roadside strips for roads 

 from 16.4 to 29.5 feet wide. Assuming a road spacing of 400 feet, this 7 percent 

 would convert to a net loss of production area over the entire stand of about 1.6 

 percent. Applying the same assumptions and calculations to Landbeck's (1965) data, 

 the Scotch pine stands sustained an overall production loss of only 0.4 percent. 

 Kramer's report (1958) also demonstrated that edge effect was much greater in stands 

 50 to 80 years old than in younger stands. Therefore, as the stands approach maturity 

 we may expect a greater edge effect and less production loss than the 1.4 percent 

 estimated in this study. 



This study was based on western white pine stands, but this close agreement 

 with the above noted studies indicates that a similar response could be expected 

 with other species. In fact, those species with a greater crown expansion potential 

 than western white pine should utilize road openings more fully. 



CONCLUSIONS 



On soils comparable to those studied (relatively stable with good drainage charac- 

 teristics) near maximum production can be maintained concurrently with continued 

 maintenance of a permanent road system. To do so, it is necessary to keep roads 

 reasonably narrow (less than 14 feet). Furthermore, trees must occupy the site up to 

 the toe of the fill and near the top of the cut for maximum utilization of space. 



The potential loss of timber-producing land is minor and can be reduced to 

 practically zero if road widths are kept to the minimum actually needed. With large, 

 modern equipment one of our perennial problems in road building is keeping width 

 to the minimum needed for access and safety. The arguments for narrow roads (except 

 for main roads) need to be reemphasized and enforced in current practices. Narrow 

 roads are cheaper to build, less maintenance is required, they are more stable from 

 a watershed protection standpoint, and they are less offensive from a recreational 

 (esthetic) view, especially if the new stand is established to make maximum utilization 

 of the space. 



