FOREST AND RANGE RESOURCES OF UTAH 



65 



SELECTION CUTTING 



The system of cutting best suited to the majority of Utah timber 

 types is called " selection cutting," which means that certain trees 

 are selected for removal. (Fig. 35.) This system is applicable to 

 western yellow pine, lodgepole pine, Engelmann spruce, Douglas 

 fir, and alpine fir. In fact, it is suitable for any trees which require 

 some shade in the seeding stage. 



To see how it works consider a stand of mature western yellow 

 pine. This stand of timber will probably contain 8,000 board feet 

 (a board foot is the equivalent of a board 12 inches square and 1 

 inch thick) per acre in trees 12 inches in diameter breast high (4% 

 feet from the ground) and larger. Such a stand is not increasing 

 in volume, as the growth put on is small and is balanced by the loss 

 of those trees dying out. Most of the timber volume will be in large 

 veterans, but there will be a considerable number of thrifty younger 



Figure 35. — Selection cutting. All trees with white spots on the trunk will be cut 



trees from 12 to 20 inches in diameter at breast height and a lot of 

 smaller poles (2 to 6 inches in diameter) and saplings (3 feet high 

 and 2 inches in 'diameter). 



Suppose the whole forest unit has been considered, and it has 

 been determined that this area should be logged over every 50 years. 

 To do this it will be necessary to leave enough trees now to provide 

 a merchantable stand 50 years hence, with the idea in mind that the 

 selection cutting made then will leave ample growing stock for a 

 third cut. Studies of the growth of western yellow pine indicate 

 that 2,000 board feet per acre left in thrifty, well-distributed trees 

 will grow to at least 8,000 board feet per acre in 50 years. The 

 forester in charge therefore goes through the timber and marks for 

 cutting all the mature, overmature, and defective trees, being careful 

 to leave thrifty, fast-growing trees to the amount of at least 2,000 

 board feet per acre. When the marked trees : have been removed, 

 the forest is considerably opened up and the surface soil disturbed 



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