SHELTER-WOOD COMPARTMENT SYSTEM. 95 



the new wood. At the end of the regeneration period the new 

 wood consists of a series of groups, of greater or smaller 

 extent, ranging in age from one to thirty, forty, or fifty years, 

 according to circumstances, and it presents a picture of un- 

 evenness which is preserved throughout life. The wood grows 

 on until the next regeneration comes round, when operations 

 are commenced in the oldest groups and gradually, in the 

 course of thirty, forty, or fifty years, extended to the 

 youngest. 



During regeneration all seed years are taken advantage of, 

 and artificial help, where necessary or desirable, is not 

 excluded. 



The group system is frequently combined with the strip 

 system, mentioned above. 



b. E.rtcrnal Duwjers. 

 Owing to the uneven age of the several groups, the young 

 growth receives both top and side shelter ; hence it is more 

 fully protected against frost and drought than under the 

 shelter- wood compartment system. It is also claimed for the 

 system, that the trees withstand storms and damage by snow 

 or ice better. In this respect further data are required before 

 a final conclusion can be arrived at. 



r. Produrfioii of Wood. 

 Whether the total production is greater or smaller than 

 under either of the previously mentioned two systems, can 

 only be proved by actual statistics in the course of time ; the 

 system affords the means of producing valuable large timber, 

 as, towards the end of the rotation, the finest trees can be 

 placed comparatively free for a term of thirty to fifty years. 



(h Effecl upon tJte Factors of the Locatity. 

 This is doubtless more favourable than under the shelter- 

 wood compartment system, as the soil is more carefully 

 sheltered, accompanied by a more complete preservation of 

 an even state of moisture. 



