SAMPLE ESTIMATING FORMULAE 



We wish to emphasize the development of estimates for compartments and sub- 

 compartments, with forest totals developed from sums over the smaller subpopulations . 

 Accordingly, the following expressions will differ slightly from those that might be 

 derived solely for forest totals. 



Summaries of Tree Characteristics Within Stands 



Let {character} be any characteristic of the sample unit that is being summarized. 

 At the tree level, it could be the volume of the tree or any portion of it. If number 

 of trees per acre is the item of interest, then {character} would be unity at the tree 

 level. To obtain breakdowns by species, or tree class, {character} would be defined 

 only for the species or class being summarized and zero otherwise. 





number of points in stand "fe" 









= {character} of jth tree in stand "/c" 









= basal area of the jth tree in stand ' 



k'' 





'ik 



= total of {character} per acre of the 



kt\\ 



stand in subcompartment "i 



baf 



= basal area factor for point sampling 



(sq 



ft. /tree) 



fpa 



= fixed plot area (acres) 







= i y -M 



(1) 



where 



4j - 



if dbh > 5 in. 



baf 



fpa if dbh < 5 in, 



Summaries of Stand Characteristics in Sub compartments Selected for Ground Examination 

 A^^ = area of the feth stand in subcompartment "i" 



1 if A:th stand in subcompartment "i" is in the photo stratum 

 if not in that stratum 



^^■^/zi ^ total of {character} per acre in the subcompartment "i" for only those 

 stands in photo stratum "/z" 



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