Figure 1 .--Crown injury in a 30- to 

 40-year-old stand of ponderosa 

 pine 2 months after a fire. 



RESULTS 



Mortality 



First-year mortality was closely correlated with crown injury. Consider- 

 ing all size classes together, every tree died that had been burned 95 to 100 

 percent, but only 73 percent of the trees died in the 90 to 94 percent class. 

 Only 32 percent of the 80 to 89 percent class died; and of those trees burned 

 79 percent or less, only zero to 17 percent died (fig. 2). 



For nearly every given degree of crown injury more small trees died than 

 large trees; but when injury was very severe (greater than 95 percent) all 

 died. Fifty percent of the 2-inch trees died when crown injury was only 50 

 percent, yet no 3- inch trees having less than 70 percent crown injury died 

 during the first year after the fire. Few trees 4 inches d.b.h. or larger 

 died unless crown damage was greater than 80 percent. Exceptions to this were 

 trees believed killed by subsequent beetle attacks. 



Mortality was not related to crown classes (dominant, codominant, etc.) 

 except as crown classes were correlated with tree size. 



3 



