16 BULLETIN 154, U. S. DEPARTMENT OF AGRICULTURE. - 
the formation of a thick sod of grass that comparatively few seed- 
lings are able to gain a foothold after that time. ae 
GROWTH. 
The rate of growth of lodgepole varies greatly with the quality 
of the site and the density of the stand. Other conditions being the 
same, the most rapid growth takes place on the best sites, but over- 
stocking often reduces the rate of growth in such situations to a 
point at which it is considerably less than in more normally stocked 
stands on poorer sites. The effect upon growth of the density of the 
stand is discussed under “ Factors influencing yield.” 
On account of the wide variation in lodgepole’s rate of growth, it is 
impossible to give figures which will be universally applicable. Table 
‘2 shows what may be expected under certain conditions. The data 
were obtained from 468 average trees cut by the arbitrary group 
method in the course of a yield study on the Deerlodge Forest, con- 
ducted in fully stocked stands on sites better than the average for 
that Forest. Since the stands were approximately fully stocked, and 
in some cases overstocked, the diameter growth shown is somewhat 
less than that which may be expected in the case of trees growing in 
stands of moderate density. On the other hand, since the sites were 
better than the average, the height growth shown is somewhat above 
the average. 
TABLE 2.—Average growth of lodgepole pine in fully stocked. stands on the 
Deerlodge National Forest, Montana, on slightly better than average sites, 
based on 468 average trees, of which 158 were dominant. 
Pee wiche ar Height. Volume. 
Age in years. 4 
| Average | Doms Average Den Average ee Average Poult, 
trees. Z trees. _ trees. trees. a 
trees. trees. trees. trees 
Board Board Cubic Cubic 
Inches. Inches. Feet. Feet. feet. fect feet.2 Seet.2 
Oa es er 0.4 0.5 3 ’. amie ay Coen mR NRE Od RE oa eee we ena PE 8 tl 
P/V ee es Sa i eee 2 1.9 10 1D ae ee ae ee Ae oe ee | ee ee eee 
See eo se ee eee Peek By 19 20) ee cl Sica Berets | ee ete 0.5 ile 
AQ RN WE oN er = 3.0 4.4 27 BD: taal eet See ee | ee te 9 2. 
CTU a Las oo ras Sete 3.8 5.6 33 BS. Sales Sees | eeeaeee 1.5 3. 
COR ee eee 4.5 6.6 38 7. Vasa ie espe ea 5 PAA | 5: 
NO See Sora ASS aes 5.2 7.4 42 AGG tae ee 20 3.0 “ls 
RO eae Ss Se ae eyes 5.8 8.2 47 OAS ies Shee: 35 4.1 9. 
ee ae ae 6.4 8.9 51 58 5 45 6.2 12. 
O02 See ae ee 6.9 9.5 54 62 20 60 8.6 15. 
IO Ree ene oe 7:4 10.1 58 66 30 75 10.0 18. 
AZO ere oa ae oe 7.9 10.7 61 70 40 90 11.4 2a. 
P3022 ees oat Sec ee SR Sete TD, 65 ke 50 105 UBB) 26. 
TAQ SS Ee Pe oe ee eee 8.7 11.8 68 76 60 120 15e5 30. 
150) ee aS ees 9.2 12.3 (Al 79 70 135 18.0 34. 
AGO Sor ete a ee oe 9.6 ADS 74 81.5 80 150 20.0 39. 
17 (Vb oe eae ee as Se 10.0 gy a 77 84 90 170 22.0 44. 
TOS Soe = OE ae 10.4 13.8 80 86.5 100 190 24.2 49. 
OO Se ee ee foe 10.8 14.3 83 89 110 215 26.5 54. 
Uh Deen ee ae aes HAE 14.7 85 91.5 125 240 30.0 60. 
1 The board foot volume is based on a minimum log of 6-inch top diameter and 16-foot length, scaled by 
the Scribner Decimal C rule. 
2 The cubie foot volume includes only the usable portion of the trunk from above the stump, usually 
from 6 to 10 inches high, to a diameter of 3 inches in the top. 
