MAMMAL HABITATS AND THE FUTURE 



211 



use most of their energy in getting food; there is not enough 

 food value in the meager grass to produce much milk and beef. 

 Too many ditchbanks, stream sides, and slopes are still 

 farmed so severely that soil ^vashes downstream with every rain. 

 Too much ^vater is allowed to run to sea — water that should 

 sink deep into our soils to form a continuous store for human 

 use. Too many brooks and rivers are fouled by oil and sewage, 

 chemical waste and soil. Modern science can use or dispose 

 of stream pollutants in harmless ways. Contour farming on 

 slopes, restoration of plant cover to gullies and ravines, can hold 



Fig. 116. — Left, managed, unpastured woodland; right, pastured 

 woodland. Pastured woodland is uneconomical because it produces 

 poor forage and little or no replacement timber. 



