36 Forestry Quarterly. 



amount of wash, and a decrease in the regularity of water-supply, 

 from a burned slope during the first year. There is much im- 

 provement during the second and third years, and normal con- 

 ditions will ensue not earlier than the fourth year after burning. 

 Of course the damage done by a single fire is somewhat propor- 

 tional to the amount of leaves and rubbish on the land. 



Pasturing, especially of hogs, sheep and goats, is decidedly in- 

 jurious to mountain lands. 'Hogs, in addition to making numerous 

 trails which may become channels for excessive washing, are con- 

 tinually rooting up and loosening the soil, and thus tend decidedly 

 to increase surface movement of the soil. They also kill out the 

 undergrowth. Sheep and goats, if run long or in large numbers 

 upon the mountain lands, almost completely kill out the under- 

 growth, and thus tend materially to increase erosion and to 

 diminish the amount of rainfall transmitted to the sub-soil. 

 From observations thus far made the only conclusion is that the 

 mountain lands of this region can stand only a minimum of 

 pasturage without serious damage. This is especially true of 

 south- and southwest-lying slopes. 



The factor producing the greatest disturbance of all is clearing 

 the land and cultivation of crops. The habit of the mountain 

 farmer is to deaden the trees of a patch of mountain side or top 

 and to cultivate it until the fertility of the soil is exhausted, which 

 usually takes from four to eight years. The patch is then aban- 

 doned and another patch deadened, cultivated, and in turn, aban- 

 doned. This process is continued until all the available land has 

 been used up, when the farmer must move to a new locality. To 

 understand how rapidly these steep cultivated slopes wash, one 

 has only to visit them during and immediately after a heavy rain. 

 The water coming from them is so heavily laden with sediment 

 that it resembles a mud-flow rather than a stream of the usually 

 clear water of the mountains. Land which has been cultivated 

 until exhausted recovers very slowly, and thus the fallow slopes 

 with bare surface and deep-cut gullies continue to wash and to 

 menace the lower land and the streams with their waste. A 

 large number of such slopes that have lain fallow for periods of 

 from I to 15 years were visited and studied. All were only 

 scantily protected by secondary growth of vegetation, and were 

 thus subject to excessive erosion. Such old fields furnish sur- 

 prisingly great amounts of sediment to the swift-flowing streams 

 which carry it to the main rivers. It seems clear that the logical 

 way to prevent excessive erosion and dangerous silting of the 

 channel in the lower courses of the Savannah River, is to pro- 

 tect the still forested slopes of its tributary streams, and to do 

 everything possible to restore a cover of vegetation to fallow areas 

 which exist. 



The streams from this area furnish a supply of water to the 



