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LOGGING PRACTICE IN THE LAKE STATES 55 
While jack pine grows faster than either of the best pines up to 30 
or 40 years, after that the yields from Norway and white pine will be 
greater if the soil is at all suitable for those species. 
The area of jack pine is very large and is increasing. With the 
better fire protection that is coming throughout the Lake States 
region, jack pine will be relatively abundant in the next 15 to 20 
years. On the other hand, the supply of large saw-log material 
is rapidly decreasing, and the shortage of such material will be 
felt more and more. It may, therefore, pay the timber owner 
gradually to convert jack-pine forests on soils suited to Norway and 
white pine to the better species. Where jack pine, as in the northern 
part of Minnesota, occurs with white and black spruce, it may pay 
even to favor the spruces in the future stands. 
The best way to do this is by partial cutting the jack pine. If 
only 50 per cent of the merchantable stand is removed conditions 
will be more favorable for the growth of white spruce or Norway and 
white pine than for jack pine. Jack pine springs up most apna? 
antly on areas which have been once burned over, and requires full 
sunlight for its best development. It suffers even from light shade. 
For this reason, if jack pine is not cut clean but about half of the 
merchantable stand left for another 40 years to ripen into saw-log 
material, the chances are that the second growth will contain less 
jack pine and a larger proportion of white spruce and the better 
pines, depending upon the locality and the presence of these species 
near the area. In this way the jack pine may be gradually converted 
into amore valuable forest. It is a safe procedure, for, if Norway and 
white pine or white spruce fail to come up, it will still be possible 
to obtain reproduction of jack pine when the remaining mature jack 
pine is cut, if not before. 
Leaving jack pine to grow for 80 years to saw-log size will also 
prove advantageous, as the stumpage price of jack pine saw-log mate- 
rial is only a little lower than that of red and white pine. Aside from 
other considerations, the thinning of jack pine should stimulate the 
growth of the remaining trees. : 
Partially cutting jack pine stands as a means of converting them 
into a more valuable coniferous forest seems to be especially adapted 
to the pole-wood stands of jack pine found on the thin outcrop soils 
in northeastern Minnesota. Those jack pine stands are now in the 
natural process of conversion into white pine, spruce, or Norway pine 
forests. These species, however, do not come in in sufficient abundance 
until the jack pine stands thin out naturally with age. Cutting out 
the smaller trees for pulpwood will encourage this conversion process. 
After reproduction of the more valuable coniferous trees has been 
abundantly and thoroughly established, the mature jack pine trees 
can be cut clean and the conversion process completed. Where par- 
tial cutting is impracticable and yet the object is to convert jack pine 
into more valuable stands of Norway or even white pine, the planting 
of these species is the only quick procedure. (Pl. 7, A.) 
SLASH DISPOSAL 
When jack pine is cut clean to release the reproduction of better 
species, the slash should be disposed of over the entire area by pro- 
gressive piling and burning, as in Norway and white pine stands, 
