Effect of Forest Fires on Trees. 203 



ing fire. Thus each successive fire may kill enough to counter- 

 balance the growth since the last, or even more. Like annual 

 fires they work in any existing cavities in the butts and enlarge 

 them. 



IV. FIRE IN RELATION TO SPROUTING. 



No discussion of the fire problem in southern New England can 

 fail to deal with it in relation to sprouting. 



The relative sprouting ability of trees from stumps is fairly 

 well known. Whether this same relation holds after fire, cannot 

 at present be answered. Probably it does. All the well-known 

 laws of sprouting hold as well for fire-killing boles as for cut 

 stumps. When a fire burns down a tree it kills it, but sometimes 

 only the bole is killed. Sprouting may then be possible. If the 

 root system has been injured it will be feeble. The presence of a 

 dead trunk may impede the growth of the sprouts and injure 

 them when it falls. Ten to fifteen years usually effects the de- 

 struction of a trunk killed by surface fires, so that their subse- 

 quent development is not seriously interfered with. The presence 

 of a destructive fungus in the rotting stub may be more serious. 

 However not all fungi living on dead wood can infect living. 



The season of a fire has much to do with the vigor of sprouting, 

 which is better after one in spring than in late summer or fall. 

 Late sprouts are apt to be frost killed. 



A sprout from the base of a fire-killed trunk is to all intents 

 and purposes a new tree, and the whole subject of sprouting might 

 be considered under Reproduction were it not that injured trees 

 also sprout. If they are tolerant and not of large size, some of 

 their sprouts may come through and exist as equals with them. 

 This is not uncommon with Iron wood (Carpinus Caroliniana) . 

 More often the sprouts live for a few years only to die for lack 

 of space or light. Sprouting is of value when a bole is killed, but 

 not when it is injured. The sprout growth dissipates the energy 

 of the parent, preventing it from putting forth all effort to repair 

 its wounds and increase its growth. 



The effect of periodic fires in young and middle-aged sprout 

 stands is interesting to observe. A fire kills or injures the trunks 

 so that they sprout from the base. The next fire kills or injures 

 the survivors of the first crop. Another crop takes their place, is 



13 



