JACK PINE. 33 



Table 31 (appendix) gives the yields obtained from thinnings of 

 well-managed stands of Scotch pine in Europe. A comparison of 

 these with the final yields given in Table 30 indicates cumulative 

 intermediate returns, on quality III or average sites, of 5 to 40 per 

 cent on any rotation between the ages of 30 and 50 years, inclusive. 

 Similar results could probably be secured from the management of 

 jack pine where the market conditions w^ere favorable for utilizing 

 the product of such cuttings. 



Instead of clean cutting young jack pine stands for cordwood, as 

 is often done, owners would do well to get their firewood by thinning 

 their stands and allow the better trees to remain and produce a crop 

 of timber valuable for purposes other than fuel. Jack pine stands 

 should preferably be thinned as early as 20 years of age. (See PL 

 XVI.) Thinnings to be eifective should be severe, leaving the 

 crowns of the trees fully isolated on all sides for a space of 5 to 10 

 feet. There would be considerably more danger from windfall and 

 windbreak to trees left after severe thinnings in older stands than in 

 younger — an important reason for thinning before the stand is 25 

 years old. 



Very dense, overstocked sapling stands, from 6 to 8 feet high and 

 from 5 to 6 years in age, such as are liable to stagnate, can be bene- 

 ficially thinned by clearing of parallel lanes about 6 feet wide at from 

 8 to 12 foot intervals through the stand, and also thinning out trees 

 in the rows to be left, or the stand may be thinned in two series of 

 clear-cut parallel lanes at right angles to each other. From 800 to 

 1,200 trees to the acre, or 5 to 7 to the square rod, is a sufficient 

 number to leave after thiiming, provided some trees are left on every 

 square rod of area and no large gaps are made in the stand. The 

 saplings cut should be dragged out of the thicket and burned as a 

 fire-protective measure and to prevent insects from breeding in the 

 slash. 



Clearing of lanes in overstocked saphng stands from 3 to 5 feet in 

 height could be accomplished with greater ease than in taller stands, 

 as brush scythes and brush hooks could be used, but would be inad- 

 visable on poor dry soils where the establishment of a soil cover and 

 good humous conditions are important. Lanes cut in such stands 

 should, in general, be about the same width as the height of the 

 stand. 



