Blytt-Sernander Scheme 



The chronological series of floras and kinds of vegetation 

 following the last glaciation in Scandinavia; comprising the 

 boreal, Atlantic, sub-boreal, and sub-Atlantic stages. 



Bog 



An undrained or imperfectly drained area, with a vegeta- 

 tion complex composed of sedges, shrubs (Ericaceous, espe- 

 cially), and sphagnum mosses, typically with peat formation; 

 often with an area of open water. Frequently used in various 

 meanings, in the sense of Marsh, Swamp, Moor, Fen. cf. 

 Muskeg, Heath, Raised bog. 



Bog Soil 



A mucky or peaty surface horizon underlaid by peat. 



Bole 



The unbranched trunk or stem of a tree. 



Bolson 



A depression lacking exterior drainage in an arid or semi- 

 arid region, term used in southwestern United States and 

 Mexico. 



Bonitdtion 



The state of well being of a population, as indicated by 

 the number of individuals, cf. Ecological bonitation. 



Border Dike 



Ridges of earth constructed to hold irrigation water 

 within certain limits in a field. 



Border Irrigation 



Flooding areas in fields by the use of Border dikes. 



Border Strip 



A zone or strip surrounding a sample plot, usually given 

 the same treatment as the plot. 



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