Forest Types of Baden. 453 



58 feet). Again after the trees have reached an age of 100 years 

 the reproductive power begins to fall off and in a few of the old 

 stands natural regeneration is no longer possible. 



Unless allowed to become too old, Silver Fir reproduces abun- 

 dantly and owing to its shade enduring qualities no preparatory 

 fellings are made, because whenever a little light is let in, by wind- 

 falls or the cutting of cancerous trees, advance growth follows 

 almost immediately. Fellings are afterwards made in favor of 

 these groups and the stands regenerated under a system which is 

 a combination of the group and the shelter wood compartment 

 systems. Accidental fellings, which are always rather high in 

 coniferous forest, are especially plentiful here owing to the 

 number of trees which become attacked by cancer or are blown 

 down by wind during such a long rotation. 



No preparatory fellings are therefore necessary, and at least 

 25% of the area is usually occupied by advance growth before 

 regular regeneration fellings are commenced. It is only in the 

 least accessible districts, where the old cancerous trees have been 

 left and have escaf>ed the effects of wind, that advance growth is 

 not found and natural regeneration is excluded. 



There are many drawbacks to this system of regeneration, the 

 chief being that the timber must be extracted through so much 

 young growth ; however, the timber can be and generally is let 

 down by slides. Another drawback is that it is necessary' to prune 

 the big trees before felling to prevent them damaging the young 

 growth. This is both expensive and dangerous. In fact if the 

 cost of pruning were added, as it should be, to the cultural costs, 

 it would be found that natural regeneration under this system cost 

 more than artificial cultures under the clear cutting system. 



It is said in favor of this system that the trees acquire light 

 increment during this long regeneration period. But this is not 

 exactly true, as the trees have not been prepared for it ; it is only 

 when a tree has a large spreading crown that it is possible for it 

 to take full advantage of an increase of light. 



The following are a few suggestions as to the best method of 

 treating these stands under the present system of regeneration, 

 the period of which should, however, be shortened : 



I. Too much should not be cut at once or it will not be possible 

 to stack it for transport. 



