A NATIONAL PLAN FOR AMERICAN FORESTRY 



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timber during the years 1925 to 1929, inclusive. This period was 

 chosen as covering the years for which more and better statistics were 

 available than for any other recent period. It avoids not only the 

 subnormal swing of the economic depression, but also the earlier 

 trends that are out of line with present-day production. The drain 

 averages thus obtained represent merely the conditions for these years 

 and are not necessarily to be considered as an index of future wood 

 requirements. 



Timber destroyed includes only large-scale timber losses, not sal- 

 vaged, over and above the normal losses through the death and decay 

 of individual trees, for which allowance is made in estimating growth. 

 Losses other than those from fire and naval-stores operations are 

 averaged for the period 1920 to 1929, instead of 1925-29, the longer 

 period permitting the inclusion of a greater number of less frequent, 

 cataclysmic disturbances and thus insuring a better average figure. 



TABLE 10. Total timber cut or destroyed each year in the commercial forests of the 

 United States, by agencies l 



1 For definiation, explanations, and general make-up of this table see footnotes in subsequent timber-loss 

 tables and also refer to text. 



2 Timber cut annually, 1925 to 1929, inclusive. 



3 Timber killed annually by fire and not utilized, 1925 to 1929, inclusive. 



4 Timber killed annually by insects, disease, drought, wind, naval-stores operations, etc., and not utilized, 

 1920 to 1929, inclusive. 



The total drain figure of 16 billion cubic feet (table 10) is in contrast 

 with that of 26 billion cubic feet estimated by the Forest Service in 

 1920 in the report on Senate Resolution 311, on the basis of the 

 1910-19 period. The differences between the two estimates are due 

 in part to the decrease in the use of wood for fuel from 110 million 

 cords in the 1920 estimate to 61 million in the present estimate. 

 Elimination of bark (as in the case of the timber stand and growth 

 estimates) and the use of improved conversion factors also had the 

 effect of reducing the present estimate. The present figure for saw- 

 timber drain (59 billion board feet) is actually larger than the 1920 

 estimate (56 billion feet), because of the different and improved 

 methods employed in making the estimate. 



