48 graves: place of forestry among sciences 



is exposed to direct light by cutting. It was found similarly that 

 in old Douglas fir burns, where the leaf litter was not completely 

 destroyed, the young growth invariably sprung up from- seed that 

 had escaped fire and had been lying dormant in the ground. 

 Should a second fire go through the young stand before it reaches 

 the bearing stage, the land may become a complete waste, at 

 least for hundreds of years, although there may be seed trees left 

 on the ground. This conclusively proves that the young growth 

 comes from the seed stored in the ground before cutting took 

 place and not from the seed scattered after cutting by the seed 

 trees left. 



The wonderful capacity of the leaf litter and duff of the cool, 

 dark forests of the Northwest to act as a storage medium for the 

 seed until favorable conditions for its germination occur is con- 

 fined not only to the Douglas fir and western white pine but to the 

 seed of other species which often grow together with them, such as 

 Noble fir, amabilis fir, western red cedar, and hemlock. The 

 subsequent appearance of other species in a Douglas fir or western 

 white pine stand depends apparently to a large extent upon the 

 seed stored in the ground at a time when the original forest still 

 existed. This discovery revolutionizes our conception of the 

 succession of forest stands, since it shows that the future com- 

 position of the forest is determined by the seed stored in the leaf 

 litter; and the appearance of seedlings first of one species and then 

 of another results simply from the differences in the relative 

 endurance of seed of the different species that are lying in the 

 ground. Besides being of scientific importance this discovery 

 has also a great practical significance. It accentuates the disas- 

 trous consequence of a second fire in an old burn because no more 

 seed remains in the ground while the capacity of the few seed 

 trees that may be on the burn is very limited in restocking the 

 ground. This discovery enabled the Service to change materially 

 the present methods of cutting in the white pine and Douglas fir 

 forests, to the mutual advantage of the Government and of the 

 logging operators. 



I shall give briefly a few other illustrations of the life of the 

 forest which stamp it as a distinct plant society. 



