fire: its influence upon the forest crop. 11 



dering on the company's land. They are set in order to burn away the 

 underbrush and open the woods for hunting and hog ranging. Thirty 

 or forty years ago the whole forest was burned over regularly each 

 year in order to improve the grazing, but this custom has been but 

 little followed of late. A few of the tires are caused by the careless- 

 ness of loggers or campers. 



The effect of fire on this forest may be summed up as follows: 



(1) The young growth of all species, but especially that of pine, is 

 very seriously damaged or totally destroyed. 



(2) Mature and middle-aged trees are damaged to some extent. 



(3) The soil is constantly impoverished through the destruction of 

 the leaf litter. 



If the forest is to be managed with a view to future crops, it is 

 necessary to obtain young growth which will develop into a first-class 

 stand of timber. This is impossible unless fire is kept out. A partial 

 protection is worse than none, for if the forest be guarded for five or 

 six years and then burned over, the tire feeds on the accumulated 

 litter, and the damage done is much greater than if light fires occurred 

 each year. Therefore, if protection is attempted it should be thorough. 



The diagram herewith (fig. 1) is exceedingly significant. It illus- 

 trates the occurrence of pine according to diameter classes, and it 

 reveals a peculiar irregularity in the number of trees in these classes. 

 This irregularity is in all probability due to the damaging effects of 

 forest fires in past years. The diagram shows the average number of 

 trees per acre of Shortleaf and Loblolly Pine, separately and combined, 

 of diameters from 2 to 40 inches. It will be seen that the three curves 

 for diameters from 40 to 22 inches are quite regular, the number of 

 trees per acre increasing steadily as the diameter decreases. At 22 

 inches, however, a decided break occurs, and from this point down to 

 14, 15, and 16 inches the same increase in the number of trees per acre 

 does not take place. From these points down to 2 inches the increase 

 again becomes very regular. 



Now it is apparent that if no breaks occurred in the curves at the 

 22-inch point, the lines would have continued on as indicated by the 

 short broken lines of the diagram, and the number of trees per acre of 

 smaller diameter would have been much larger. In other words, the 

 number of trees in the smaller diameter classes at the present time is 

 insufficient to maintain the present stand of mature trees. 



Loblolly Pine, when '22 inches in diameter, is about 100 years old. 

 The curves show that the proportion of younger trees has been 

 reduced bv some disturbing: influence. Such an influence is tire— 

 not a great fire, but repeated fires of ordinary severity, such as the 

 forest now suffers from. As the region was slowly entered by settlers 

 these fires would begin. The trees which are now one hundred years 

 old had by that time reached such a development that they were not 

 affected; the injury was then, as' now. chiefly to the young growth. 



