JACK PINE, ae 
Table 31 (appendix) gives the yields obtained from thinnings of 
well-managed stands of Scotch pme in Hurope. A comparison of 
these with the final yields given in Table 30 mdicates 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 were 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 PI. 
XVI.) Thinnings to be effective 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 thinning, 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 sapling 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. 
