216 



TIMBER RESOURCES FOR AMERICA'S FUTURE 



Lightning causes notable damage in many 

 regions but is probably worst in the Southern 

 Rocky Mountain Region. The loss of individual 

 trees by lightning strikes is minor compared to the 

 fires and bark beetle infestations that so often 

 follow. Lightning also exposes trees to attack by 

 oak wilt and other diseases. 



Drought causes important losses periodically in 

 most regions, with California, the Southern 

 Rockies, the Plains, and the South suffering the 

 most frequently. Pine plantations were damaged 

 extensively during the 1952 drought in the South. 

 When the full effects of droughts are known, the 

 damages ascribed to them may be increased. 

 Some maladies of unknown cause, such as birch 

 dieback and sweetgum. blight, and attacks by 

 some insects, such as the southern pine beetle, 

 may prove to be brought about primarily by 

 drought. 



Other weather-induced losses are caused by rock 

 and snow slides, hot winds in the West, and by 

 a variety of other disturbances. 



There are some opportunities for reducing 

 losses from weather damage. Harvest cuts can 

 be regulated to leave sufficient trees properly 

 spaced and in patterns that help reduce blowdown. 

 Logging of steep areas can be minimized to avoid 

 snow and earth slides following heavy rains. 

 Forest composition can be regulated toward wind- 

 or ice-resistant species. The reduction of loss 

 following damage from, extreme weather conditions 

 is, however, largely a matter of salvage. 



Where weather damage is sporadic and light, 

 there is little opportunity for salvage unless the 

 killed timber is readily accessible to current logging 

 operations or the area is under intensive manage- 

 ment. Where weather-damaged timber is con- 

 centrated and of high value, there is usually a 

 greater opportunity for salvage, provided that 

 logging operations are shifted into the damaged 

 timber and that access roads are built before the 

 timber values decline. One of tlie significant ad- 

 vantages of prompt and thorough salvage is the 

 reduction of insect outbreaks that often move into 

 adjacent undamaged timber. 



Recent wind damage in the West has been in 

 rugged timbered areas requiring a large investment 

 for access roads. Li the Nortliern Rocky Moun- 

 tain Region, for example, an appropriation of 

 $9,000,000 was obtained in 1953 to build roads to 

 365 million board-feet of timber blown down on 

 national-forest lands in 1949. An even larger 

 road construction program to salvage windthrown 

 and insect-killed timber on public lands in the 

 Pacific Northwest has been found necessary by 

 both private and public agencies. Most private 

 land in the West is more accessible than the public 

 forests, which contain vast inaccessible areas on 

 which millions of board-feet of killed timber go to 

 waste annually because of lack of roads. A 



greatly stimulated access road program is needed 

 for these areas. 



In the North and South, accessibility is good 

 enough to make major salvage operations generalh" 

 feasible. In the New England hurricane of 1938, 

 almost half of the timber killed was salvaged. 

 Salvage from storm damage usually requires quick 

 opportunities for use of the wood, readj^ access, 

 and miU facilities to handle unexpectedly large 

 quantities of killed timber. 



CATASTROPHIC TIMBER DESTRUC- 

 TION SINCE 1900 



Every so often, the timber destroyed by fire, in- 

 sects, disease, or wind is so great that the event is 

 considered a catastrophe. For the purpose of this 

 Timber Resource Review, a catastrophe is defined 

 as an unpredictable event characterized by a combi- 

 nation of unusual severity and concentrated loss in 

 both time and area and of sufficient magnitude to 

 cause major dislocation of forest management or 

 timber utilization in the region affected. The 

 Tillamook burn of 1933, the New England hurri- 

 cane of 1938, the Engelmann spruce beetle destruc- 

 tion in Colorado between 1940 and 1951, and the 

 chestnut blight are examples of the sort of events 

 considered catastrophes in this report. When fire 

 or weather is the cause, the damage is usually done 

 within a single year. Losses from insects and dis- 

 ease usually take more than a 5"ear to reach 

 catastrophic proportions. 



In estimating our capacity to meet future timber 

 needs, allowance must be made not only for the 

 largely expected or reasonably predictable losses 

 from destructive forces, but also for the unpre- 

 dictable catastrophic losses that will undoubtedly 

 occur at intervals in the future. As table 133 

 indicates, catastrophes since 1900 have killed more 

 than 122 billion board-feet, of which approximate- 

 ly 16 billion were salvaged. Thus the net timber 

 loss from these events is estimated to average over 

 2 billion board-feet a year. 



Insects have been the greatest single cause of 

 catastrophic loss. Theii' outbreaks have destroyed 

 more than 52 billion board-feet since 1900. Fire 

 killed nearly 32 billion board-feet. Wind killed 

 over 19 biUion, and disease 18 billion board-feet. 



The West, with a net catastrophic loss of 79 

 bilHon board-feet since 1900 (table 134), had 72 

 percent and the East 28 percent of the total 

 catastrophic loss. This difference is probablj^ due 

 mainly to the larger volumes of timber per acre 

 in the West and the more extensive areas of 

 virgin forest: virgin stands are particularly sus- 

 ceptible to insect attack, wind, and fire. 



Three catastrophic fires are listed in table 133. 

 These are the Yacolt fires of 1902, the Idaho- 

 Montana fires of 1910, and the Tillamook burn 

 of 1933. The famous Cloquet fire of 1918 in 



