172 ECONOMICS OF FORESTRY. 



must be maintained for all the years of removal, 

 and they occasion also otherwise greater expenses 

 in the harvest than the concentrated logging in the 

 clearing system, which may be done over tempo- 

 rary roads. Where, as in Germany, most forest 

 districts are provided with well-built permanent 

 road systems, gradual removal methods are often 

 probably the least expensive; but in the United 

 States, in most places, unless water transportation 

 can be relied upon, a gradual removal system 

 means heavy initial outlays for roads, which may 

 make the clearing followed by planting the cheaper 

 method. It is in most conditions also the surer; 

 for a complete success of the young crop can, in 

 most cases, be forced. In the natural regeneration 

 methods there are elements of uncertainty, the seed 

 years may not come when expected ; in a mixed 

 forest, which, for many reasons, is the most desira- 

 ble form, the species seed irregularly, have different 

 requirements of light, so that the composition can- 

 not be very well controlled ; the damage and loss 

 occasioned in the young crop by the removal of 

 the old crop must be discounted in the final result ; 

 and besides, where the removal is very slow, the 

 young crop is impeded in its development by the 

 shade of the old crop. These systems, therefore, 

 are better adapted to shade-enduring species than 

 to light-needing. The main argument and the 

 most important in favor of these methods is that 

 they furnish protection to the soil, preventing its 



