108 SILVICULTURE METHODS OF NATURAL REPRODUCTION 



growth. This often necessitates the thinning of young stands known 

 as black-jack groups. In rather rare instances the entire stand is 

 found to be over-mature and it becomes necessary to resort to clear 

 cutting with the reservation of four to six seed trees per acre. In the 

 Southwest, grazing must be closely correlated with time of cutting in 

 order to assure reproduction. Good seed years are infrequent, and a 

 combination of good seed years and reasonably wet summer seasons 

 is essential for the establishment of new growth. Slash disposal is 

 rarely a problem in this type; the method of disposal varies from 

 lopping and scattering the slash with the breaking up of the area 

 into control units, to complete disposal by piling and burning. 



Western White Pine Type. Western white pine, though frequently 

 found in pure stands, more often occurs in association with white fir, 

 western hemlock, Douglas fir, western red cedar, Engelmann spruce, 

 and western larch. All these associate species, with the exception 

 of larch, are tolerant of shade. Since western white pine is rather 

 intolerant of shade, some silvicultural system must be followed which 

 approaches clear cutting. Partial opening up of the stand where a 

 large proportion of the composition is made up of tolerants (shade- 

 enduring species) merely encourages these species, and the continua- 

 tion of such a practice results in a conversion to a forest of low-quality 

 trees. 



Three rather distinct conditions are found in the western white 

 pine type, namely: 



1. A two-storied forest of almost pure pine 80 to 140 years old; 

 a condition usually resulting from ground fires. 



2. A forest less than 200 years old, occurring either pure or in 

 mixture with many tolerant species. 



3. A forest 200 to 500 years old the white pine climax type 

 where all but a few large pines have passed out of the stand which is 

 represented by old defective trees of western hemlock, western red 

 cedar, white pine, and occasional western larch, in the order named. 

 If the stand is not disturbed by fire, wind, insects, or the hand of man 

 it will eventually become a pure stand of defective worthless hemlock. 



Case 1 is the least common of the three conditions named. It can 

 best be handled on what approaches a shelterwood system of cutting 

 with the removal of about 50% of the stand. Such treatment results 

 in rapid stimulation of growth in the reserved trees and an almost 

 immediate restocking of white pine in the created openings. Slash 

 is piled and burned. 



