

YIELD. Bit 
Here the trees, which were all veterans, totaled by volume table 
analysis 66,110 board feet, or 33,055 board feet per acre. The enor- 
mous volume of single groups of mature trees is illustrated by a plot 
of one twenty-third of an acre in extent on the Zuni National Forest 
which totaled 8,767 board feet or 201,641 board feet per acre. 
INCREMENT OF STANDS. 
Table 18 gives the results of measurements of two 5-acre plots in a 
pure, fully stocked stand of blackjack, and shows the mean annual 
increment per acre that may be expected in a fully stocked stand of 
this species. 
TABLE 18.—Yield per acre of fully stocked blackjack. 




| Number of Moan 
Present Average Average see ue ce _ annual 
age. height. diameter. cach Osan per acre. pee 
diameter. Penge 
Board feet. | Board feet. 
ZIG byl see OE Se ss 62 34.3 11,9 115.8 6, 326 102.0 
Oi eee see ESee Senne As 82 42.0 12:3 130.8 7,590 92.5 
eraieens ee et 72 | 38.1 1 123.3 6, 958 96.6 





No reliable yield table for western yellow pine in the Southwest 
exists, though it is planned during 1911 and 1912 to measure a large 
number of sample plots in fully stocked, even-aged stands, on which 
such a table may be based. A tentative yield table for yellow pine 
has been compiled on the Kootenai National Forest, in Montana. In 
that region a 70-year-old stand on second quality soil is estimated to 
yield 7,400 board feet per acre. In Table 18 it is shown that a 72- 
year-old stand in the Datil National Forest on average soil averaged 
6,958 board feet per acre. In Montana there were 240 trees per acre, 
9 inches in diameter and 51 feet in height, while on the Datil there 
were 123.3 trees per acre, 12.1 inches in diameter and 38.1 feet in 
height. Though the stand in the Southwest is larger in diameter, it 
is shorter than that in Montana, and there are fewer trees per acre. 
Adapting the Montana figures to the southwest, it may be estimated 
that on average soil a fully stocked stand of western yellow pine will 
give the following yield per acre: 
TABLE 19.—Estimate of the yield of average fully stocked stand of western yellow 
pine from 40 to 140 years. 
Yield per 
acre. 
Yield per 
acre. 
Yield per 
g 
Age. acre. 

Years. Board feet. Years. Board feet. || Years. Board feet. 

AQ Me a= 4,000 SO Sees UU) ai) WAY See ce 10, 900 
OO eirals = 4,900 Seer ee 8,700 US Seesoe 11, 400 
i) eae 5,850 Ieee ee 9,500 TAD en sae 12,000 
MOSz co 824 6, 900 DO Kea Ss 2 10, 250 





