68 Conservation Reader 



These slopes were once covered with grass and the rivu- 

 lets ran down them without doing any harm. But so many 

 sheep were pastured here that the grass was killed. The 

 roots, which once formed a thick protecting sod, are now 

 decaying. How quickly the rivulets have taken advantage 

 of the improtected slopes! 



The road leads still upward until it brings us to where 

 there were once pine forests. The lumbermen cut off all 

 the trees, and then fire came and burned the decaying vege- 

 tation which once lay spread o^'er the groimd. Now aU 

 that remains is bare earth and blackened stumps. 



What are the raindrops doing here? They gather in 

 rivulets just as they do on the once grassy hillside; but 

 because there are so many roots still remaining in the ground 

 they have not done much work. They are not loitering, 

 however, and by and by, when the roots have rotted, they 

 wiU seize their chance and begin tearing away the soil from 

 the mountain side. 



But this is not the end of the road. Farther up we come 

 to the primeval forests, where the giant trees stand just as 

 they did before men came. Here we can see how the slopes 

 are protected, for in making the road the workmen cut deep 

 into the hillside. They first removed a layer of pine needles 

 and decaying branches. Then they cut through a layer 

 of soil about two feet thick which was completely filled with 

 httle roots of trees and bushes. Below this they came to 

 the soft subsoil, which contained only a few roots, and at 

 the bottom they reached the soHd rock. 



The layer of roots and soU at the top of the bank, you can 

 see from the picture, now overhangs the road, because the 

 raindrops which beat against the bank have washed away 



