142 



V. 



Several times in this paiier it has l)eeii necessary t<» eall attention to 

 liie forest conditions of the driftless area. While this subject does not. 

 in strictness, come within the view of a geologist, nevertheless the succes.s 

 or failure of a water-sni)i)]y system, in a region where steep slopes pre- 

 ponderate, is so intimately bound up with forest problems, that it may 

 not be out of place to devote a little space to the consideration of this 

 topic. 



A'ery little virgin timber is left standing in southern Indiana. Where 

 tlie timber has not been removed entirely, it has been closely culled, and 

 in many instances burned over, so that the stand is often thin and the 

 forest cover poor. The writer has often been struck by the character of 

 the woods in lirown County, which gives the impression of being largely 

 under forest. And so it is, if one considers merely the area occupied 

 mainly by trees; but when one notes carefully the character of the stand, 

 one is innnediately imjiressed with the fact that scarcely a tree can be 

 found that apjiears to be over fifty years old, and much of the stand con- 

 sists of mere saplings and inferior copjnce. Cutting is still going on in 

 the whole of the driftless area, and the writer has seen tracts of many 

 acres of steep slopes denuded of their trees within the last five years. The 

 fate of these sloi)es, ur.der the type of farming generally practiced in the 

 legion, is ]iathetic (Fig. 0.). (Jnllying begins immediately, especially 

 where the soil consists largely of clay, and absorbs the rainwater slowly, 

 and in a few years the hillside is a scarred ruin. The regimen of the 

 streams is radically changed. Floods increase in fiecpiency and violence. 

 Springs that formerly had a steady and abundant flow throughout the 

 year, are i-educed to dwindling threads of water throughout the drj- sea- 

 son. 



From the standiioint of watcr->-upiily. one of the most serious of these 

 effects is the change of stream regimen. As CJlenn' has pointed out in the 

 southern Appalachians, whether or not the total rainfall of a region is 

 alTected by deforestation, it can be demonstrated that the regimen of the 

 streams is notably changtMl. lie has shown, and the same thing can be 

 shown in southern Indiana, that in regions still under adequate forest 

 cover, the streams are clear even at flood stage. He also points out the 



^ Olcnn, L. C, Denudation and Erosion in the Southern Appalachians. U. S. 

 Geol. Surv., Professional Paper Xo. 72. ]!tll. 



