second tract of 47,000 board feet at 70 years must be reduced 15 
per cent, which will amount to 39,950 feet. The third tract 30 
years from now will yield 80 per cent of 32,000 board feet or 
25,600 feet. The following tabulation gives the results for the 
entire area: 
: Yield 2 
Cutting age per acre Area | Total yield 
Board feet; Acres | Board feet 
GO; VORTS 5 oh ak 2 Se ie ol eee 56, 700 250 | 14,175, 000 
COMORES ie Ne ke a ee RN oie eg eg gee 39, 950 250 9, 987, 500 
SOV ORES sah FSH Be ees 25. 600 250 6, 400, 000 
+1 Bo} 2) a ee ee eNO NE < Re Me ge Ae ef ea 750 | 30, 562, 500 
APPLICATION OF STAND TABLES 
It has been found that, regardless of age and site, fully stocked 
southern pine stands of the same average diameter have the 
same range of diameters and the same percentage of trees in any 
diameter class. A stand table (Table 161) has therefore been 
prepared to show, for each of the four species, the percentage of 
trees at and above 2 inches, 4 inches, 6 inches, etc., contained 
in stands of various average diameters. In order to learn from 
the stand tables the number of trees of any particular diameter 
in a fully stocked stand on a given site and at a given age, it is 
only necessary to obtain from the yield tables for the specified 
age and site the diameter of the average tree and the total number 
of trees. Both figures should be for the entire stand, i. e., all 
trees 2 inches in diameter breast high aad over. 
_ As an illustration of the process, suppose that the number of 4 
and 5 inch trees is to be determined in a fully stocked loblolly 
pine stand, 25 years old, on a 90-foot site. Table 34 shows that 
the diameter breast high of this stand is 7 inches, and Table 36 
that the total number of trees is 540. Table 151 gives the per- 
centage of trees 4 inches or larger in a 7-inch stand as 90, and of 
trees 6 inches or larger as 66. The difference, or 24 per cent, is 
the proportion of 4-inch and 5-inch trees; 24 per cent of 540 is 
130. The number of trees in the 4-inch and 5-inch classes is 
therefore 130. 
Tables 162, 163, 164, and 165, giving the absolute number of 
trees at and above various 2-inch limits on average sites at 
various ages, have been prepared by this method by interpola- 
tion in the percentage stand tables. If the number of trees ina 
single inch class, or above odd inches, is desired, interpolation 
in these tables is again necessary. Because the intervals between 
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