LOGGING PRACTICE IN THE LAKE STATES 13 
conditions partial cutting of jack pine, when not followed by fire, 
may increase the proportion of Norway pine in the second growth. 
When the jack pine on the thin, rocky soil in northeastern Minne- 
sota, as exemplified in the Superior National Forest and surrounding 
country, is cut clean and the slashings burned, the second growth 
will usually be jack pine. When jack pine is not cut clean, or even 
when it is cut clean but the slashings are not burned, the second 
growth is apt to be a mixture of white pine, white and black spruce, 
balsam fir, aspen, and birch, with little or no jack pine. The soil 
of the out-crop region, although thin, is fertile and is a great battle 
ground or tension zone for the occupancy of which several species 
are contending. Only fires or clear cutting followed by fires can 
turn over the ground to the sole possession of jack pine unmixed 
with white pine, birch, and aspen. The soil naturally is more 
adapted to white pine and spruce than to jack pine, as is clearly indi- 
cated by the remnant of the original forest which existed in this 
region before the severe fires of over half a century ago. (Pl. 1B.) 
In the natural course of development without interference by man 
the jack-pine stands on the thin but fertile soils of northeastern 
Minnesota are gradually reverting to white pine and spruce. In the 
older jack-pine stands, even down to 60 years, white pine and spruce 
are slowly replacing the jack pine. Different stages in this process 
may be found throughout the region, from pure jack-pine stands 
with only a smattering of small white pine and spruce to mixed 
stands of jack pine, white pine, spruce, and balsam fir, almost of the 
same size and height. Fires and even burning of slashings in this 
region, besides favoring jack pine, are disastrous because of their 
effect on the thin soil. When fire has destroyed the soil and the rock 
is exposed the recovery of the land to forest, even to jack pine, is 
very slow and the resulting stands are inferior. 
ASPEN AND PAPER BIRCH FOLLOW CLEAR CUTTING AND FIRES 
ON HARDWOOD OR WHITE PINE LAND 
Aspen and birch stands, since as a rule they result from clear cut- 
ting and burning of the hardwoods or the white pine on the better 
soils, may be considered as a stage in the development of hardwood 
and white-pine forests. If the cut-over land is protected from fire, 
and if seed from conifers is available, some conifers may also be 
found in the growth of aspen and birch which will spring up. On 
the better-drained lands these will be white pine, and farther north, 
spruce and balsam fir; on the moister sites, spruce and cedar, or, in 
some instances, hardwoods such as maple and basswood. (PI. 2, 
B and C.) 
The commonly prevailing opinion that aspen and birch stands in 
the course of time invariably change into coniferous stands is not 
supported by actual facts. Aspen and birch stands may eventually 
be succeeded by spruce and pine, but only when these trees get a 
start on the cut-over land simultaneously with the aspen and birch. 
Whenever they are found in mixture with aspen and birch they prove 
to be practically the same age as the aspen, and thus to have started 
