GROWTH AND UTILIZATION 



151 



Annual Mortality 



Because of losses from fire, insects, diseases, 

 wind, and other causes, net annual growth as 

 reported in the foregoing section is less than the 

 amount of wood actually produced in the com- 

 mercial forests. The amount, distribution, and 

 rate of this annual mortality is the subject of this 

 section. 



The annual mortality for 1952 is estimated at 

 12.5 billion board-feet of sawtimber, or 3.5 billion 

 cubic feet of growing stock (table 92). This esti- 

 mate ascribes a loss to 1952 on the basis of current 

 estimates tempered by known trends over a long 

 period of years, exclusive of catastrophic losses. 

 This concept is adopted to reduce the wide year- 



to-year impacts of severe fires or outbreaks of 

 destructive insects and diseases.^' 



The annual mortality of softwood sawtimber is 

 about four times that of hardwood sawtimber 

 (table 92 and fig. 60). However, softwood grow- 

 ing-stock mortality is not quite twice as great as 

 hardwood growing-stock mortality. These rela- 

 tions are approximately the same as for timber 

 volume. 



3- These estimates differ slightly from estimates of actual 

 mortalitj' experienced in 1952 as reported in the section 

 on Forest Protection, p. 185. The differences were entirely 

 in the Northern Rocky Mountain Region, where insect 

 losses in 1952 were greater than the trend level, and losses 

 due to disease and weather and animals were slightly less. 

 For more detail, see tables 17 and 64 to 68 of Basic Sta- 

 tistics in the appendix. 



Table 92. — Annual timber mortality in the United States and Coastal Alaska, by section and region, 1952 ^ 



Section and region 



Growing stock 



Live sawtimber 





Total 



Softwood 



Hardwood 



Total 



Softwood 



Hardwood 



North: 



New England _ _ _ 



Million 

 cu. ft. 

 298 

 233 

 485 

 102 

 28 



Million 



cu. ft. 



99 



64 



122 



4 



2 



Million 



cu. ft. 



199 



169 



363 



98 



26 



Million 

 bd.-ft. 

 645 

 354 

 698 

 312 

 70 



Million 



bd.-ft. 



268 



115 



209 



13 



5 



Million 

 bd.-ft. 

 377 



Middle Atlantic _ - - 



239 



Lake States 



Central 



Plains . _ _ 



489 



299 



65 







Total _-_-- - -- _ _.. _ 



1, 146 



291 



855 



2,079 



610 



1, 469 







South: 



South Atlantic _ . . _ 



95 

 314 

 220 



64 



149 



85 



31 

 165 

 135 



267 

 841 

 660 



191 

 455 

 326 



76 



Southeast 



West Gulf . - 



386 

 334 







Total 



629 



298 



331 



1,768 



972 



796 



West: 



Pacific Northwest: 



Douglas-fir subregion 



551 

 196 



537 

 196 



14 



3, 105 

 932 



3,056 

 932 



49 



Pine subregion 









Total ^ 



California _ . _ 



747 

 359 

 308 

 200 



733 

 336 

 306 

 179 



14 



23 



2 



21 



4,037 



1, 865 



1,475 



906 



3,988 



1, 811 



1,472 



849 



49 

 54 



Northern Rocky Mountain 



Southern Rocky Mountain 



3 



57 



Total _ 



1, 614 



1,554 



60 



8,283 



8, 120 



163 







Total, United States . _ - 



3,389 

 100 



2, 143 

 100 



1, 246 



12, 130 

 392 



9,702 

 392 



2, 428 



Coastal Alaska 



(-) 



United States and Coastal Alaska 



3,489 



2,243 



1,246 



12, 522 



10, 094 



2, 428 







' Estimates represent the current level of mortality 

 indicated by trends over a long period of years as deter- 

 mined in 1952. For more detailed statistics see appendix 

 tables 17 and 64. These estimates differ slightly from 



estimates of actual mortality experienced in 1952 as 

 reported in the section on Forest Protection. 

 2 Less than 0.5 million. 



4a!l2!)6 O— 58 11 



