APPLIED ECOLOGY 



349 



Natural landscaping is a recent development resulting from 

 man's modern engineering activities, which drastically change to- 

 pography, drainage, and vegetation when he constructs modern 

 highways, dams, and airports. Great exposures of subsoil in cuts 

 and fills require cover and replanting not only for aesthetic rea- 

 sons but also to check erosion and slumping. It is to be expected 

 that engineers should give first consideration to the efficiency of 

 installation and use of a project under construction, but, when this 



FIG. 187. The old and the modern manner of handling a road cut. Note 

 the gradual back slope, seeded surface, and shallow, sodded runoff channel, 

 all designed to check erosion.— U. S. Soil Conservation Service. 



