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A NATIONAL PLAN FOR AMERICAN FORESTRY 



Fires are more often fatal to small than to large timber, but per- 

 haps the greatest loss is in trees that are wounded but not killed. 

 Trees injured at the base usually do not die but continue to grow 

 and occupy space. Many of them become infected, through the 

 fire scars, with wood-rotting fungi. The decay may sometimes be 

 arrested, but it may also spread in the wood of the trunk, greatly 

 reducing the quantity and value of the final product. The trees 

 thus crippled continue to spread their crowns and thus prevent the 

 successful development of reproduction. In a study by the Forest 

 Products Laboratory of small sawmill utilization in Appalachian 

 hardwoods, it was found that three fifths of the total defect was 

 attributed to fire injury. The total defect in this instance amounted 

 to 25 percent of the volume. 



The effect of repeated fires on a hardwood forest is well brought out 

 by the results of a study made by the Central States Forest Experi- 

 ment Station in a mixed oak stand in northern Arkansas, the results 

 of which are summarized in table 2. Here will be seen that defective 

 trees comprise from 22 to 65 percent of the total number by species 

 and size class, and that the smaller size classes contain the most 

 defective trees. This means that the young growth upon which 

 dependence for the future stand must be placed, is already 50 percent 

 or more defective. A fact worth recording is that only three trees on 

 the 105 plots were surely of seedling origin. 



TABLE 2. Composition of stand and percentage of defective trees following repeated 

 fires in a mixed oak stand, Arkansas l 



1 Based on 105 plots of 0.2 acre. 



In the same study, 435 sprouts, ranging in size up to 2.5 inches, 

 were cut and the condition of the stem recorded. (Table 3.) One- 

 third of the white and black oak reproduction (the most desirable 

 components of this stand) show decay in the stems. Obviously the 

 future of this stand is not promising. 



TABLE 3. Defect in sprout reproduction 



