APPRAISAL OF FIRE DAMAGE TO IMMATURE TIMBER 

 FOR STATISTICAL PURPOSES 



Bv F. G. Clark 



Forest Examiner, U. S. Forest Serz'icc 



There has always been a need for a method of appraising fire damage 

 to immature timlier when the values obtained are to be used for statis- 

 tical purposes. In general, these values have been arbitrarily fixed for 

 the various species, or a flat rate applied to all, with no great thought 

 toward working these values out on a definite basis or differentiating 

 between the dift'erent species. It is believed that basis for these values 

 should be expressed in a formula to be used in preparing a table of 

 values which will give consistent results when applied to any given 

 region and to any given number of species. 



The use of straight expectation or replacement methods when ap- 

 plied to a region in the estimating of reproduction killed by fire, espe- 

 cially when that value is to be used for statistical purposes only, do not 

 give satisfactory results. The principal disadvantage of the expectation 

 method is that the major premises — the stumpage price and the yield — 

 must be assumed. One other disadvantage of the expectation method 

 is that the younger age classes of our slow-growing species, as the 

 yellow pine and Douglas fir on the poorer sites, show a negative value, 

 after assuming average yields and moderate stumpage prices. 



On the other hand, a straight replacement formula with only varia- 

 tions being due to difference in cost of growing nursery stock and field 

 planting. The market value of the w^ood or its intrinsic qualities has 

 no place in the formula. 



A modified replacement formula is proposed in this paper which is 

 intended to overcome the difficulties mentioned. It is modified in the 

 following respects : 



I. The cost of planting is reduced by a percentage represented by the propor- 

 tion of artificial to natural reproduction which experience indicates holds good 

 over large burned areas. 



For example, if it is found that it will be necessary to plant 30 per cent of all 



burned area in a region in order to secure satisfactory restocking, then 30 per 



cent of the planting charge per acre would be assessed against every acre burned. 



This figure may, of course, be changed for each type or for each species if the 



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