Oct. i, 1917 Reproduction from Seed Stored in the Forest Floor 
25 
Since the seed must be produced by the stand before it is destroyed, 
the age at which different species begin to produce seed is of the utmost 
importance. It varies greatly, and this variation alone is often the 
controlling factor in determining the composition of the second growth. 
For example, when western white pine, Douglas fir, and knobcone 
pine (.Finns attenuata Lemmon.) appear in a mixed stand which is 
destroyed by fire, all of these species may again appear in the next 
stand; but if this second growth is destroyed by fire when it is from 10 
to 12 years old the next stand will consist principally, if not wholly, of 
knobcone pine. The knobcone pine begins producing seed when it is 
6 years old and is producing good crops of seed at 10 years; while the 
white pine and Douglas fir bear only occasional cones at ages under 12 
years. Therefore the knobcone pine is the only species which has 
any seed present to produce a forest stand following the second fire. 
Instances of such types are the knobcone pine types on the Siskiyou 
National Forest. 
For this same reason, fires which destroy young growth before it is of 
seeding age invariably produce a denuded area by precluding any pos¬ 
sibility of immediate reproduction; hence, the great need for fire pro¬ 
tection in young stands of timber. Areas of immature stands when 
destroyed by a second fire can be restocked only by the slow process of 
wind disseminated seed. Hence, the viability and delayed germination 
of forest seeds serves to explain many conditions in the virgin forest and 
its reestablishment after one or more fires. The nature and severity of 
the fire and the age of the forest are shown to be the principal factors in 
determining whether reproduction will or will not follow a bum in a 
virgin forest. 
The practical value of stored seed in the forest floor for restocking 
cut-over areas depends on the condition in which the forest floor is left 
after cutting. As has been shown, the duff must not be burned or all 
of the seed is destroyed. In order to avoid the destruction of the duff, 
it is necessary to pile the slash and bum the piles when the fire will not 
spread over the entire surface of the ground. This method has proved 
satisfactory in the white-pine region of Idaho, where piling of slash is 
feasible. In the Douglas-fir region of the coast the piling of slash would 
not be practicable because of the large amount of debris and the conse¬ 
quent cost. The large percentage of the surface which would of neces¬ 
sity be burned over even by pile burning would reduce the value of the 
operation for conserving seed stored in the duff, which is usually all 
destroyed by broadcast burning of slash. 
In regions where broadcast burning of slash is the only practical 
method of disposing of the debris left after logging, the seed trees after 
all may have to be depended upon to reseed the* area, in which case it 
will be necessary to know just how much seeding can be expected from 
such seed trees. 
