I04 THE SELECTION METHOD 



tively organized for annual or short period jdeld on a clear- 

 cutting or shelterwood method. 



Disadvantages. — i . Since the mature trees are scattered 

 throughout the whole stand and are intermixed with repro- 

 duction and small trees logging costs more than under other 

 methods. 



2. Due to the mixture of age classes, it is diflBcult to pre- 

 vent in the logging injury to the immature trees which form 

 the forest capital. 



3. Grazing cannot be permitted since reproduction is m 

 progress continually. 



4. The timber produced averages lower in grade than that 

 grown in evenaged stands. It is more apt to be knotty due 

 to the greater crown development of the individual tree. To 

 some extent the site, on which the selection method is ordi- 

 narily employed accounts for this. Selection forest has been 

 used principally on poor sites in exposed positions and at 

 high elevations as a protective forest. On such situations 

 the timber produced under any method is of lower quality 

 than that produced on better sites. 



5. To apply intensively requires great skill on the part of 

 the forester. This results from the complex nature of the 

 age distribution in the stand. 



Whether the method gives a lower increment than other 

 methods of high forest has been a point of controversy abroad 

 for many years. Some authors contend that the greater area 

 of foliage per tree and the more complete use of available 

 nutrients, resulting from the mixing of young and old trees 

 with root-systems penetrating to different depths, must work 

 for greater production under the selection method. The argu- 

 ment against this is that the retardation of the growth of 

 young and middle-aged trees, through shading by older ones, 

 more than offsets these items. It is not imtil the last half of 



