114 THE PRINCIPLES OF HANDLING WOODLANDS 



species are apt to compete in the new growth, and retard, 

 or in some cases entirely prevent, reproduction of the 

 desired species. Thus, in a mixed forest of white pine 

 and hardwoods, hardwood trees very commonly form the 

 bulk of the second growth after a clearing, even where 

 abundant seed-trees of white pine have been left standing. 



If good reproduction is secured, the new stand is 

 essentially even-aged. If the seed-trees are not cut after 

 reproduction, they are so scattered that they do not inter- 

 fere in a material way with the development of the new 

 stand. 



The investment is usually small. The value of the 

 trees left standing is under most circumstances not over 

 $2 to $ 5 per acre. Sometimes, however, the system is 

 used in a virgin forest where the only adequate seed-trees 

 have considerable merchantable value. If the trees are 

 very valuable, the probabilities are that it will pay to 

 come back for them in a second cutting after they have 

 accomplished their reproductive function. If it is im- 

 possible to return for them, and they are very valuable, it 

 would not pay to use the system at all. In general, the 

 results in reproduction are so uncertain that it would not 

 pay to use this system where the investment in securing 

 reproduction would be over $3 to |? per acre. 



Practical Application. — The system has already 

 been used in this country in a number of instances. The 

 work conducted on the largest scale is that on the Min- 

 nesota National Forest. This area formerly belonged to 

 the Chippewa Indians. When the land was relinquished 



