et BULLETIN 1294, U. S. DEPARTMENT OF AGRICULTURE 
The cull percentage, it will be noted, is, as usual, much higher in the 
two inferior species than in the pines; but even in the pines it must 
not be disregarded. It is not implied that all the decay was charge- 
able to fire, but the greater part of it can be directly traced to fire. 
TABLE 11.—Percentage of cull in important species 
[National forest timber sales] 
axi- | Mini = 
Species Average mum mum 
cull cull cull 
Sales Total 
Per cent | Per cent | Per cent Board feet 
Wwesternuyellow2pine Sic esta 95 eee eee 3. 4 8. 2 12 10} 13, 649,000 
SHEATAD ING pe ere © GeO eae ee eed ee 10.1 RSS: 2.5 8 | 10,605, 000 
DOU ELAS IR Sac r= ase oot ee a ea ee ee eas Be 14.5 22. 0 3.0 5 3, 738, 000 
Aish a U9 08 CR elk eI pila i Oe Sea Ree I trai ee 13. 2 30. 1 30 9 7, 197, 000 
InCenSe (COC AL ass. oa sae ee Pee ee ep 26. 5 46.3 7.8 7 2, 286, 000 
FIRE DAMAGE TO YOUNG GROWTH 
Within the past 15 or 20 years, or since fire protection has been 
attempted, conditions in the virgin forest have changed radically from 
the time when fires ran unchecked. The most outstanding of these 
changes is the enormous number of young forest trees that have 
appeared as individuals and in groups, or, in the more open virgin 
stand, as a veritable blanket under the mature timber. This remark- 
able change is in itself proof that the virgin forest as we find it does 
not represent the productive capacity of the land, for if an area of 
ground is fully occupied by a mature crop of timber the young individu- 
als can not obtain a foothold because the available moisture and light 
are already fully utilized. That this alteration is due solely to fire 
protection is clearly evident from the descriptions of the virgin forest 
of a half century ago by historians and early settlers. In this picture 
the dominant note is the openness of the forest, emphasized in the oft- 
repeated statement that one could ride anywhere or could see for long 
distances through the timber. The general occurrence of young — 
erowth or advance reproduction in the virgin forest to-day is the 
effort of nature, in response to fire protection, to utilize the full grow- 
ing power of the land, and to restore the broken and understocked 
forest to a more normal condition. 
Even a light fire is sufficient to destroy the seedlings and saplings 
in a stand; that is, the young trees which must become established if 
forests are to persist indefinitely. Unless some reproduction is able 
to become established and survive, it requires little imagination to 
see that, with fires occurring on the average about eight years apart, 
and even with the very lowest rate of loss to the largest trees that 
has been found on any of the fires studied in detail, the forest must 
eventually disappear. The presence and history of brush fields well 
illustrate this. On the other hand, repeatedly burned-over timber 
stands prove that in many cases the forest has Heed able to reproduce 
itself about as rapidly as fire has eliminated individual old trees and 
the smaller, younger trees. Perhaps the most remarkable thing m 
this entire survey of the cumulative effects of fire is the fact that so 
large a percentage of the forest has persisted. 
Se ee es 
