A SUMMARY OF THE TIMBER RESOURCE REVIEW 



63 



cubic feet of mortality and 10.4 billion cubic feet 

 of growth impact. 



On a sectional basis, about 70 percent of saw- 

 timber mortality occurred in the West. The re- 

 mainder was about equally divided between the 

 North and South (table 40). In terms of growth 

 impact, however, the distribution of loss was quite 

 different; loss was almost equally divided among 

 all sections of the country. 



By causative agents, disease, insects, and fire 

 were the most important, regardless of whether 

 the comparisons are in terms of sawtimber or 

 growing stock, growth impact or mortality, except 

 that weather in 1952 outranked both disease and 

 fire as a mortality cause with respect to both saw- 

 timber and growing stock (table 39). These rela- 

 tionships are shown graphically for sawtimber in 

 figure 29. 



INSECTS 



DISEASES 



GROWTH LOSS 



31.1 Billion bd.-ft. 



FIRE 



MORTALITY 



12.7 bil. bd.-ft. 



I WEATHER 



OTHER 



total annual growth impact of sawtimber 

 43.8 million board-feet 



16 14 12 10 8 6 4 2 



2 4 6 



includes Coastal Alaska 



Figure 29 



439296 O — 58 6 



