138 FOREST PROTECTION 



Par. 13. Protection Against Erosion. 



The adult forest does not require any protection from erosion—usu- 

 ally so. 



It must be remembered, on the other hand, that "civilization" (by 

 ditching the slopes on the hills; by cutting roads and railroads into the soil; 

 by draining the bottom-lands for farming purposes) increases the rapidity 

 of the subterranean and of the superficial drainage; that it results in a par- 

 tial destruction of the soil on the hill sides. 



Erosion, in the present geological acra, is not so active, nevertheless, 

 as it was in prior periods. 



A forest plantation on the hill side suffers during its early stages from 

 erosion where the soil consists of clay, and where the plough has preceded 

 the establishment of the embryo-forest. 



Some seedlings are washed out of the soil whilst others are covered 

 by detritus. 



At Biltmore, erosion has harmed particularly the so-called "old school 

 house" plantation, in its earliest stage of development. 



As soon as the forest covers the ground fully, viz.: when the branches 

 of neighboring specimens interlace, all erosion is usually stopped and stopped 

 for good. 



Oftentimes deep gullies are cut into the side slopes during and after 

 agricultural occupancy of the soil; in such cases, the stopping of the gullies 

 by wicker works or hurdles can be recommended. 



These wicker works should not protrude more than one-half foot above 

 the surface of the soil. 



They should be made, particularly, at the upper end of the gully. It 

 is useless to make them at the lower end alone. 



These wicker works will hinder erosion to a certain extent; will quiet 

 the soil within the gully; and will allow the grasses and the weeds to occupy 

 the sides of the gully. 



The most interesting case of erosion met in Eastern America is, pos- 

 sibly, the erosion exhibited in the immediate proximity of the smelter works 

 at Ducktown, Tenn. 



Here, the hillsides were laid bare entirely at a time at which the smelters 

 used the timber for charcoal. 



Following this deforestation, the bared areas were used for roasting 

 (by the open heap method) of the copper-bearing ores. As a consequence, 

 every vestige of vegetation has been annihilated on the hillsides and eros- 

 ion has had a chance to work in an amazing degree of intensity. 



Erosion may be checked by horizontal ditches — or ditches running 

 at a very light grade; by the planting of grasses or weeds between horizon- 

 tal ditches; arid finally, by afforestation. 



There is no means better than successful afforestation by which the 

 soil can be fastened or anchored to the underlying rock. 



Afforestation as a topic of lectures belongs into "Sylviculture" and 

 into "Forest Policy." 



