A NATIONAL PLAN FOR AMERICAN FORESTRY 



219 



areas of forest laud, and has been an outstanding factor in keeping the 

 forest growth of the United States below the current drain upon our 

 timber. 



Fire and timber cutting, of course, not infrequently work together 

 with their separate effect difficult to determine. Either one can cause 

 forest deterioration or devastation. The difference between the two 

 conditions is one of degree rather than kind . The bulk of the damage, 

 however, is the result of fire after cutting. Only rarely does logging, 

 no matter how carried on, alone result in devastation, but the re- 

 sulting accumulation of highly inflammable slash invites fires. A 

 single fire in such debris may and frequently does destroy all 

 young growth and trees of seed-bearing size, leaving the area incapable 

 of restocking by natural means. This phase of the forest problem is 

 discussed under Progress in Forestry and Existing Plans in the sec- 

 tion "Current Forest Devastation and Deterioration." 



It is noteworthy that of the more than 40 million acres burned 

 annually (1926-30 period) 90 percent was in the South, and that half of 

 this was in two States. Although the area of unprotected land in- 

 cluded in these figures represents an exceedingly rough estimate, it is 

 certain that the great bulk of fire damage in terms of area burned over 

 occurred on lands which had not been placed under organized fire 

 protection. According to data available for 1930, 90 percent of the 

 total area burned in that year was land not so protected. In the 

 entire protected area the acreage burned was 1.4 percent of the total 

 whereas the corresponding figure for the unprotected area was about 

 20 percent. These figures alone show that forest fire can be controlled, 

 and they indicate the importance of extending organized fire protection 

 to the still unprotected land. 



INSECTS, DISEASE, WIND, AND DROUGHT 



Timber killed annually by disease, insects, wind, naval-stores 

 operations, and drought, and not utilized, during the years 1920 to 

 1929, inclusive, amounted to over 985 million cubic feet, including 

 592 million in saw-timber trees and 393 million in cordwood trees. 

 (Table 16.) Losses in trees of saw- timber size amounted to nearly 

 3% billion board feet, and in smaller trees to over 4 million cords. 



TABLE 16. Timber killed each year by disease, insects, drought, wind, etc., and 

 not utilized in the commercial forests of the United States, by character of growth 

 and region * 



Based upon the volume of timber killed and not utilized, 1920 to 1929, inclusive. This estimate does not 



include normal losses that are constantl 

 tion. Data compiled in cooperation wit 

 Bureau of Plant Industry, U.S. Department of Agriculture. 



y occurring in the forest but only large-scale or cataclysmic destruc- 

 ;h the Bureau of Entomology, and the Division of Forest Pathology, 



