SILVICULTURAL SYSTEMS 2^ 



applied on these alternate strips. If the period between cuttings 

 were long enough to allow the new generation to produce seed 

 this would be unnecessary, but it is not the practice to wait so 

 long. 



2. Under this method the stand is removed by a series of 

 strips, beginning on one side and progressing in the direction of 

 the prevailing wind across the area. The last strips must be 

 reproduced by some other method. An interval of several seed 

 years is allowed to elapse between the cuttings. It would, there- 

 fore, take a very long time to cut over a whole forest in this way. 

 To overcome this delay the stand is divided into several nearly 

 equal areas and a series of strips is established in each. 



/. Clear Cutting in Patches {Group Method). 



Irregular patches of unequal size are cut usually where a group 

 of reproduction is already started. These first openings are not 

 over 200 feet across and do not aggregate over one-third the 

 entire area. When these patches are entirely reproduced from 

 the surrounding stand, the cuttings are enlarged gradually until 

 all is cleared. The last strips will, of course, have to be repro- 

 duced by some other method. 



C THE SHELTERWOOD SYSTEM (STAND SYSTEM). 



There are certain disadvantages connected with all of the 

 clear-cutting systems which are overcome by the shelterwood 

 system. Under the former methods the soil is exposed and 

 reproduction is retarded by drought and frost. It is also im- 

 possible to use them with heavy-seeded trees, such as oak, 

 chestnut, and beech. 



The principle of the shelterwood system is to open and re- 

 move the stand gradually by a series of thinnings. This results 

 in reproduction under the shelter of the mother trees which are 

 not all cut until complete reproduction has been accomplished. 

 A more even distribution of seed results from this system because 

 there are large numbers of seed trees well distributed over the 

 area, and the young seedlings are protected by the shade of the 



