FOREST FIRES. i!5 



from insects and fungus diseases. This is most evident in the 

 case of White Pine, Birch, Foplar and similar soft woods, but 

 even hard woods are injured by insects if allowed to stand long 

 after being killed. 



The Killing of Half-Grown Trees by forest fires causes 

 a loss that amounts not only to the value of the timber .trees but 

 to the value of the seeding and shading trees and the forest 

 floor. The value of the trees alone in this case is not a fair 

 standard by which to measure the loss, since at this stage of 

 their growth they are making their most rapid increase/ and 

 their value should be computed as the amount upon which the 

 increase is paying a good interest. For instance, the Division 

 of Forestry of the Minnesota Experiment Station found land 

 that was well stocked with young White Pine (six inches in 

 diameter and fifty feet high) that could be bought for about one 

 dollar per acre, and yet the annual increase on the trees would 

 pay five per cent on a valuation of $100,000 for the next twenty 

 years. The reason why such a state of affairs exists is that there 

 is such great danger from fire that the investment fails to com- 

 mand the money of careful investors. 



The Destruction of the Forest Floor by fire greatly les- 

 sens the probability of an immediate renewal of valuable tree 

 growth upon the land, and therefore is one of the greatest 

 injuries to forests. The value of the forest floor can hardly be 

 estimated, but the expense that would be necessary after a fire 

 to produce conditions as favorable to the seeding of our timber 

 lands as those found in unburned forests would probably be not 

 less than twenty-five dollars per acre. 



I/ight Fires, which repeatedly run over the ground, and 

 which by the casual observer are thought to be of no impor- 

 tance, often destroy the seeds in the surface soil and the young 

 tree seedlings, besides injuring the forest flo'or, and unless such 

 fires are prevented it is impossible to secure a good growth of 

 timber on any land. The fires that burn over the land shortly 

 after it has been logged, and which feed on the tops and other 

 waste parts of the trees, generally destroy a large number of 

 young seedling trees, perhaps all of them, so that in order to 

 secure a new growth seeds must be brought from a distance. 

 Owing to the great heat developed by such fires in dry weather, 



