116 



ELEMENTARY FORESTRY. 



they are unusually destructive, and leave very little humus in the 

 top soil. For this reason land that has been burned over in this 

 way is a long time in recovering from its injuries. Besides the 

 injuries already cited, all forest fires kill or drive out much of 

 the game in our forests. 



Spring Fires are very injurious to trees, and especially ten- 

 der seedlings, for trees in the spring of the year are full of sap, 

 and can endure but little heat. 



Summer and Autumn Fires generally run deep into the 

 ground, and if the soil is very dry and of a peaty nature burn off 



Figure 30. A Fire Fall. Roots burned off and tre 

 at confusion. 



es blown down in 



. 

 great confusion. 



the roots of the trees. The result of this is that the trees are 

 blown down in great confusion, and form what are known as 

 "fire falls." Where a thick growth falls it forms an almost 

 impassable barrier, which remains in this state until decay and 

 repeated fires, extending over a long series of years, finally 

 destroy the trees, and pnliaps get the land into condition for a 

 new growth. 



