Strand 



(1) The area of bare beach above the level of high water, 

 which is subject to the action of wind. (2) The intertidal 

 portion of a beach. 



Stratification 



See Layering, Thermal stratification. 



Stratified Sampling 



In sampling vegetation or a geographic complex the 

 separation into types or blocks in order to secure the maxi- 

 mum degree of Homogeneity in the area to be sampled. 



Stratosphere 



The upper region of the atmosphere beginning about 

 six miles above the surface of the earth, in which water-vapor 

 clouds do not form and where no marked changes in temper- 

 ature take place as the altitude increases. 



Stratum 



See Layer. 



Stream 



A general term for water flowing in one direction such 

 as a rill, rivulet, brook, creek, and river. 



Streptomycin 



An Antibiotic (q. v.) produced by the mold, Streptomyces 

 griseus. 



Stress 



(1) Systemic. According to Selge the condition of an 

 animal in which large parts of the body deviate from their 

 normal resting state, either because of their activity or 

 because of an injury. (2) The total energy with which water 

 is held in the soil. 



Stressor 



A stimulus causing systemic stress. 



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