12 BULLETIN 1496, U. S. DEPARTMENT OF AGRICULTURE 
from a second-growth stand, even though much of the young hard- 
wood is left. It seems evident, therefore, that to insure hemlock 
second growth, only light cutting in the original stand can be con- 
sidered, and that fire protection must be complete. 
CLEAR CUTTING AND FIRES CHANGE NORWAY AND WHITE PINE 
FORESTS INTO JACK PINE OR ASPEN FORESTS 
In the past Norway or white pine forests have been cut clean, and 
the slashings as a rule have caught fire. Pure stands of old growth 
in the Lake States are now almost entirely lacking. There are, how- 
ever, many areas which show what has happened. When the pine 
was cut clean and the ground burned, the second growth that came 
up was, on the better or white-pine soils, either pure aspen or a mixture 
of aspen, paper birch, and red maple, and on the sandier or Norway 
pine soils, jack pine and oak. (Pl.1,C.) This is very similar to the 
second growth that comes in on hardwood land cut clean and repeat- 
edly burned, except that on the white-pine land this effect is obtained 
more quickly, after one or possibly two fires, whereas it may take 
several more burnings on the hardwood land to produce like results. 
If the land was burned only once, there is, as a rule, a fair scattering 
of pine in the new stand. ~ 
The general result is the predominance of jack pine in the second 
growth, and where the fires were repeated and particularly severe 
even the jack pine has been cleaned out and is succeeded, in Wiscon- 
sin and Michigan, by scrub oak and red maple; or, finally, the land 
has sometimes become entirely barren of tree growth. 
CLEAR CUTTING AND BURNING JACK-PINE FOREST BEGETS 
JACK PINE 
In the Lake States there are from 8,000,000 to 10,000,000 acres of 
jack-pine land, a considerable portion of which has been won by the 
jack pine at the expense of the original Norway and white pine, 
especially the former. Until a few years ago jack pine was not cut 
to any extent. At present, however, the cutting of jack pine is 
increasing rapidly. When jack pine is cut clean and the ground is 
burned, jack pine follows, except that the quality of the stand becomes 
poorer with repeated burning. Where scarlet and other oaks are 
present, as in the Lower Peninsula of Michigan, these tend to increase 
with successive fires, and ultimately the whole stand becomes unmer- 
chantable scrub or gives way to sweet fern and blueberry barrens. 
If several fires follow at short intervals before the jack pine has 
reached seeding age the pine is eliminated in a very short time and 
the ground is then occupied by brush and an irregular sod of berry 
plants, grass, sedge, lichens, and moss. 
When jack pine on sandy soils is cut clean and the ground is not 
burned or is only lightly burned, jack-pine reproduction will usually 
follow. In partial cutting of jack pine on sandy soils—a method 
that is now being used on the Minnesota National Forest, where the 
timber is cut for ties or box boards—jack pine second growth is 
assured; and if, in addition, seed trees of Norway pine are close by 
there may be a sprinkling of Norway-pine reproduction. Under such 
