THE RED SPRUCE. 
35 
Table 11. — Diameter growth of spruce (virgin) in West Virginia. 1 
[Spruce slope type.] [curved.] 
Diameter 
breast 
high. 
Absolute maximum. 
Average maximum. 
Average. 
Basis. 
Periodic 
annual 
growth. 
Time 
required 
to grow 
1 inch. 
Periodic 
annual 
growth. 
Time 
required 
to grow 
1 inch. 
Periodic 
annua! 
growth. 
Time 
required 
to grow 
1 inch. 
Inches. 
21 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
1") 
13 
17 
IS 
19 
23 
Inches. 
0.202 
.220 
.235 
.250 
.262 
.274 
.284 
.291 
.296 
.300 
.300 
.300 
.298 
.294 
.290 
.282 
.275 
.235 
.254 
.243 
Years. 
5.0 
4.5 
4.3 
4.0 
3.8 
3.6 
3.5 
3.4 
3.4 
33 
3.3 
3.3 
3.4 
3.4 
3.4 
3.5 
3.6 
3.8 
3.9 
4.1 
Inches. 
0.126 
.138 
.148 
.157 
.166 
.174 
.182 
.188 
.193 
.198 
.201 
.203 
.204 
.202 
.200 
.196 
.192 
.186 
.178 
.172 
Years. 
7.9 
7.2 
6.8 
6.4 
6.0 
5.7 
5.5 
5.3 
5.2 
5.1 
5.0 
4.9 
4.9 
5.0 
5.0 
5.1 
5.2 
5.4 
5.6 
5.8 
Inches. 
0.051 
.056 
.060 
.084 
.009 
.074 
.079 
.084 
.090 
.095 
.102 
.105 
.109 
.110 
.111 
.110 
.108 
.106 
.103 
.100 
Years. 
19.6 
17.9 
16.7 
15.6 
14.5 
13.5 
12.7 
11.9 
11.1 
10.4 
9.8 
9.4 
9.2 
9.1 
9.0 
9.1 
9.3 
9.4 
9.7 
10.0 
Trees. 
1 
3 
1 
5 
12 
24 
27 
37 
28 
42 
19 
33 
13 
17 
8 
20 
290 
i From data collected by John Folev in 1903 in Greenbrier County and including trees in all crown classes. 
2 The time required to grow to a diameter of 1 inch at breastheight was 7 years for "absolute maxi- 
mum" growth conditions, 11 years for "average maximum," and 26 years for "average." 
Diameters in even-aged stands vary directly with the age of the 
stand, so that the relationship of one of the other is of considerable 
importance. This relationship is brought out in Table 12, which is 
based on the average diameter growth of the dominant (including 
codominant) and intermediate trees. 
Table 12. — Diameter growth of red spruce in even-aged, old pasture stands in Maine, 
New Hampshire, and Vermont, according to age and site qualities. 
[Average diameter breast high i of all dominant (including codominant) and intermediate trees in stands 
of different ages.] 
Site qualities. 
Age. 
Basis. 
I. 
II. 
III. 
Sample 
Years. 
Inches. 
Inches. 
Inches. 
plots. 
20 
3.8 
3.1 
2.4 
25 
• 4.9- 
4.0 
3.2 
1 
30....... 
5.9 
4.9 
3.9 
35 
6.8 
5.7 
4.6 
* 1 
40 
7.5 
6.3 
5.2 
45 
8.1 
6.9 
5.7 
1 
50 
8.6 
7.4 
6.1 
6 
55 
9.0 
7.7 
6.4 
6 
60 
9.3 
8.0 
6.7 
8 
65.- 
9.5 j 
8.2 
7.0 
16 
70....... 
9.7 
8.5 
7.2 
14 
75 
9 9 
8.7 
7.4 
4 
80 
10.1 ! 
8.9 
7.6 
1 
85 
10 2 I 
9.0 
7.8 
90 
10.4 J 
9.2 
8.0 
95 
10-6 1 
9.4 
8.2 
1 
100 
10.8 
9.5 
8.4 
59 
From sample plot data collected in 1910. 
