Denudation 



(1) The processes by which the surface of the earth is 

 worn away, including rainfall, wind, erosion, waves, tides, 

 frost action, heating by the sun, etc. (2) The total destruction 

 of plant and animal life in an area by physical or biotic 

 means. 



Dependence 



A relationship between organisms in which one organism 

 receives benefit from the other, not reciprocal, cf. Competi- 

 tion, Symbiosis, Coaction. 



Dependency Zone (Range) 



A certain area surrounding -an area of private land, 

 within which the use of the private land may be supple- 

 mented by use of the public' land. 



Dependent Property (Range) 



Privately owned or controlled land or water judged to 

 have special claims for companionate use with certain public 

 or cooperatively controlled range land. 



Deposits 



See Allochthonous, Autochthonous, Terrigenous. 



Depth, Effective Soil 



The depth of the soil which roots of plants can penetrate 

 readily to obtain water and plant nutrients, cf. Working 

 depth. 



Desalinization 



Removal of salts from a saline soil, usually by leaching. 



Desert 



An area of land which has an arid, hot to cool climate, 

 with vegetation that is very sparse and usually shrubby. 



Deserta 



Various kinds of vegetation found in areas and on sub- 

 strata that are poor in available water for plant growth such 



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