CHAPTER IV 



THE SHELTERWOOD SYSTEM 



Underlying Principles of the Shelterwood System 



EXPERIENCE has shown that the systems of clear-cut- 

 tings with natural reproduction have certain disadvan- 

 tages which in many cases render their results uncertain 

 and unsatisfactory. The exposure of the soil often re- 

 sults in retarding reproduction through drought or frost, 

 or through competition with brush and weeds, which 

 spring up in abundance on clearings. A disadvantage 

 of the clear-cutting systems with natural reproduction is 

 that they cannot be used with trees having heavy seed. 

 All of these difficulties are in a measure overcome by 

 the application of the shelterwood system. 



The principle underlying this system is to remove 

 a given stand gradually by a series of thinnings. The 

 opening of the canopy results in reproduction over the 

 ground under the protective shelter of the trees left stand- 

 ing. These trees are then removed at one cutting, or 

 gradually, in accordance with the needs of the new crop 

 and the special requirements of market and logging. 



Advantages of the System. The special advan- 

 tages of the system are the following: 



1. The cuttings for reproduction leave a large num- 



137 



