343 
We have found trees over 12 inches breast high burned down by 
repeated fires, which means, of course, a direct loss of the merchant- 
able timber in these trees. If not killed outright by the intense heat, young 
trees are fire-scarred, the wood is finally exposed by the peeling off of the 
bark, and an entrance point thus made for the spores of wood-destroying 
fungi which start decay at the base of the tree. In such timber a heavy 
discount must be allowed in making estimates. If left for seed, it is 
very unlikely that such trees will survive long or produce good crops. 
INJURY TO REPRODUCTION 
Fires kill the young growth outright, both of sprout and seedling origin, 
the amount of complete destruction depending on the thickness of the 
bark, the black oaks and hickories evidently being more fire-resistant than 
the white oaks. Repeated burning off of sprouts may cause an abnormal 
growth of young sprouts, too dense to amount to much in restocking the 
stand and only adding fuel to the next fire. Acorns, nuts, and other seeds 
are also so scorched and burned that they will not germinate no matter 
how favorable soil conditions may be; and the opening up of the stand 
through repeated fires hinders the reproduction of the better species 
brought into unfavorable competition with a covering growth of weeds, 
grass, and inferior species like sassafras, persimmon, and sumach. This 
fact of worthless growth, and the consequent drying out of the soil due 
to burning, is changing the beech-maple type of forest to the more 
xerophytic oak-hickory type. 
INJURY TO THE SOIL 
Prior to the work of Hesselman, the main value of humus in forest 
soils was thought to be its effect upon the physical characteristics of the 
soil, increasing its water-holding capacity, rendering heavy clay soils lighter 
and better aerated, and making sandy soils more retentive of moisture and 
heat. Moore (’22) shows that humus in soil or even in sand has a decided 
effect to stimulate the growth of tree seedlings of various pines and the 
sugar maple. He also says that “the nutrient value of humus and its 
influence on rate of growth in certain forests seems amply demonstrated. 
Surface-burning in a forest, by adding ashes to the soil, may stimulate 
growth temporarily; but since it destroys the nitrogen, which seems to 
be such a large factor, and allows the remaining nutrients to be rapidly 
carried off by rain, its ultimate result must be to seriously check growth.” 
This may explain the low humus content of our upland timber soils in 
many counties as referred to by the Soil Survey. These soils have under- 
gone repeated burning, coupled with a leaching out of their soluble 
humus content. 
