CORRECTION OF YIELD TABLES FOR LOCAL USE. 
As earlier stated, the yield tables are based upon a study of 
well-stocked stands of the four species throughout the greater 
part of the range of southern pines. ‘The results of this study 
indicated that geographical location had no consistent effect 
upon the yields of stands of equal site quality. It, therefore, 
follows that the productive capacity of any pine tract whose 
site is correctly identified may be determined from the tables, 
regardless of its geographical location. 
It is believed that local yield tables will not be appreciably 
more correct than the regional yield tables, particularly if based 
on any fewer data than the regionaltables. The construction of 
local tables will involve a very considerable expenditure of time 
and money. However, if a check of the volume tables shows 
the need for correction on account of local peculiarities in the 
form of individual trees, the yield tables should be correspond- 
ingly corrected. The general method recommended for cor- 
recting for different limits of utilization, described below, should 
be equally satisfactory in correcting for locality. 
A further check of the applicability of the yield tables to any 
given locality may be made through a comparison of the actual 
measured yields of 20 or 25 local plots with corresponding yields 
in the tables. The comparison would follow the same lines as in 
checking the volume tables for local use. It will be seen from 
the footnotes to Tables 64, 96, 128, and 160 that the plots 
entering into the yield tables deviated much more widely from 
the tabular values than did the tree volumes. 
cone OF YIELD TABLES FOR DIFFERENT LIMITS OF UTI- 
If the yield tables are desired for conditions of utilization 
other than those assumed in their preparation, correction must 
be made for the actual limit of use. Probably as accurate a 
method of doing this as is ordinarily necessitated is based on the 
average breast-high diameter of the stand 2 inches diameter 
breast high and over, and the number of merchantable trees per 
acre. ‘There are two distinct steps, which are described in the 
following example: 
Assume that the loblolly yield table for board feet by the 
international rule is to be corrected, like the volume table in an 
earlier illustration, for an actual utilization to 8 inches in the 
top, rather than to the 5 inches assumed in the tables. The 
yield for a 50-year stand on a 90-foot site is wanted. An under- 
standing of the stand tables, presented under a later heading, is 
assumed. 
From the loblolly tables it appears that this stand contains 
220 trees 1.6 inches in diameter and up, and that the average 
breast-high diameter is 12 inches. The percentage stand table 
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