siliceous sinter around hot springs in Yellowstone National 

 Park. 



Sippe 



A plant in the abstract as compared to the concrete plant. 



Sirocco 



A hot, south wind, occasionally dust laden, blowing from 

 the Sahara in the Mediterranean region. 



Site 



An area delimited by fairly uniform climatic and soil 

 conditions, essentially equivalent to Habitat (q. v.). 



Site Index 



A numerical evaluation of the quality or productivity of 

 land, especially used in forest land where it is determined 

 by the rate of growth in height of one or more of the tree 

 species. 



Site Quality 



The capacity of a Site to produce vegetation, particularly 

 timber or forage. 



Skiophyte 



See Heliophobous. 



Slack 



A damp hollow, or low area, among sand dunes. 



Slash 



The branches, cull logs, uprooted trees, and other waste 

 material left on the ground after an area has been logged off. 



Slashing 



An area of forest that has been logged off and where the 

 Slash remains. 



Slate 



A fine-grained, dense rock produced from clay or shale 

 by compression, splitting readily into thin plates. 



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