330 



AMERICAN FORESTRY 



recorded in the forest itself. The 

 records are carved by the passing 

 fire* <>n the scarred veterans that 

 remain. < >n areas where the pro- 

 CCSa is not yet complete, the marks 

 of the various stages are clearly 

 distinguished. When fire injures a 

 growing tree hut. does not kill it, 

 the wound grows over. The hurtl- 

 ed spot, however, remains as a 

 dead area, and the annual rings are 

 formed around it. By counting 

 the new growth rings, the date of 

 the fire that caused the wound may 

 be determined. Most large trees 

 show clearly the effects of the many 

 fires they have survived during a 

 period, perhaps, of more than three 

 centuries. 



The occurrence, destruction, and 

 after-effects of fire in the forests of 

 the Pacific Northwest have been 

 studied by the investigators of the 

 Wind River Experiment Station 

 during the past seven years. The 

 data obtained lead to the incontro- 

 vertible conclusion that any fire is 

 a dangerous enemy to the forest, and 

 destruction it may cause depends upon 



COUNTING GROWTH RINGS TO DETERMINK 

 DATE OF FIRE 



Twenty-three rings 



IS 



shows that the fi"re occurred 23 years ago. Rainier 

 National Forest, South Central Washington. 



that the amount of 

 the type of fire into 



which it chances to develop. The 

 discussion in this article of the 

 various stages of forest destruction 

 is a summarized explanation of how 

 and why forest growth is eliminat- 

 ed by repeated fires just as surely 

 as though that destruction were ac- 

 complished by a single fire. 



The complete destruction of a 

 forest by a single fire is the most 

 conspicuous type ; hence it has been 

 regarded as the first step in the 

 process of deforestation. The de- 

 struction of a mature forest by a 

 single fire would reduce much of 

 the forested area to brush fields or 

 barren wastes were it not for the 

 adequate provisions of nature for 

 restocking such areas in large part. 

 * A mature forest usually produces 

 some seed annually and heavy crops 

 periodically. A large part of the 

 seed produced is eaten by rodents, 

 but these same forest inhabitants 

 store away seed in the duff and soil 

 of the forest floor for their future 

 use. Some of these stores are not 

 needed or are not found in the deep duff after the winter 

 is over, and so they remain in the cool, shaded forest 



since the fire scar was inflicted 

 ye 



Photograph by Wcrnsted. 



HOW A SINGLE FIRE CAN DESTROY A MATURE FOREST 



Note the 

 in cm 

 destroyed 



he bare ridge on the left-hand side of the view (south slope) where the fire was hottest. The right-hand side shows young growth coming 

 the north slope. View on "Yacolt burn" of 1902, in South Central Washington, where more than half a million acres of forest were 





