290 BOTANICAL GAZETTE [APRIL 
4. In stands that contain little or no signs of fires, the lodgepole 
pine element is absent or nearly so. 
5. Nearly all stages in the development toward this condition were 
noted. Thus, fig. 20 shows a comparatively recent clearing in a young 
lodgepole pine forest, which is in turn surrounded by a mature forest of 
western larch and Douglas spruce in which the lodgepole pine element 
is inconspicuous. Fig. 12 shows an almost pure growth of this young 
forest with mature trees of western larch in it. In another place there 
is a more mature growth in which only charred trunks of larch tell 
the tale. 
For the reasons given above, it is believed that the explanation for 
the lodgepole pine in the area plotted is the correct one. As before 
stated, observations were not limited to this immediate region, and 
many instances might be cited where burned areas similar to those 
described have become reforested with lodgepole pine. It will not 
be out of place to repeat that the advantage which it has over the 
other species in the region is due to its capacity to produce seeds 
early in life, and its habit of retaining the seeds in its cones for a 
number of years, thus preserving them for a greater or less length of 
time. In forests partially destroyed by fire the trees of western larch 
and Douglas spruce, because of the capacity of their trunks to resist 
rather severe burnings, will restock the burned areas. Fires of this 
nature, repeated sufficiently often to prevent any young lodgepoles 
from becoming old enough to produce cones, will militate against 
the latter, while Douglas spruce and western larch will have cone- 
bearing trees on the ground so long as the fires are not too intense. 
As soon as these are destroyed, then the seed supply is cut off and 
restocking from that source at least will discontinue. 
_ It will be seen readily that if the fires that have made the lodgepole 
pine condition possible are repeated every five years, for instance, the 
young growth forests of that tree will not be permitted to follow each 
other in procession, for the five-year interval between fires will be too 
short a time to permit lodgepole pine to produce seeds. Then 8 
course all forest growth will be completely destroyed and the area wil 
not become clothed with trees until restocked with seeds from the 
neighboring undestroyed forests. The further these are away, the 
longer it will take for seeds to reach the devastated area. Howevel; 
