BALSAM FIR. 
' As shown by the tables, the best growth is made on hardwood 
slope; the poorest in swamps. 
Table 15 shows the diameter growth of balsam fir in Maine for all 
types. The average growth here equals the best growth in the 
Adirondacks. On the whole, however, the periods of most rapid and 
slowest growth coincide. 
Table 15. — Diameter growth of balsam fir in Maine, on the basis of age. (All types, 
based on 456 trees.) 
Age (years). 
Diameter 
breast 
high. 
Growth 
in diam- 
eter 
every 
5 years. 
Annual 
growth 
in diam- 
eter 
within 
5-year 
period. 
Inches. 
Inches. 
Inches. 
15. 
0.4 
20 
1.2 
0.8 
6.16 
25 
2.0 
.8 
.16 j 
30 
2.7 
.14 1 
35 
3.4 
.14 | 
40 
4.1 
.14 
45 : 
4.8 
.14 
50 
5.5 
.14 
6.1 
.6 
.12 
60 
6.7 
.6 
.12 
65 
7.3 
.6 
.12 
70 
7.9 
.6 
.12 
75 
8.4 
. 5 
.10 
80 
8.9 
.5 
.10 
Annual 
Growth 
growth 
Diameter 
in diam- 
in diam- 
Age (years). 
breast 
eter 
eter 
high. 
every 
within 
5 years. 
5-year 
period. 
Inches. 
Inches. 
Inches. 
85 
9.4 
0.5 
0. 10 
90... 
9.9 
.5 
.10 
95 
10.4 
. 5 
.10 
100 
10. 7 
.3 
.06 
105 
11.0 
.3 
.06 
110 
11.3 
.3 
.06 
115 
11.6 
.3 
.06 
120 
11.9 
.3 
.06 
125 
12.1 
.2 
.04 
130 
12.3 
.2 
.04 
135 
12.5 
*2 
.04 
140 
12.6 
!l 
.02 
145 
12.8 
. 2 
.04 
150 
12.9 
!i 
.02 
SUMMARY. 
Diameter breast high (inches). 
Age 
(years). 
Years 
required 
to grow 
1 inch. 
Diameter breast high (inches). 
Age 
(years). 
Years 
required 
to grow 
1 inch. 
1 
19 
25 
32 
39 
47 
54 
62 
19 
6 
7 
7 
8 
8 
8 
71 
81 
91 
105 
123 
152 
9 
10 
10 
14 
18 
29 
2 
9 
3 
10 
4 
11 
12 
6 
13 
7 
EFFECT OF OPENING UP FOREST UPON DIAMETER GROWTH. 
That the diameter growth of balsam fir is stimulated by opening 
up the forest is indicated by measurements of trees growing on 
uncut and on culled land (Table 16). 
Table 16. — Diameter grovjth of balsam fir, Grafton County, N. H., on uncut and culled 
land. 
Present diameter breast high 
(inches). 
Diameter, in inches, 
breast high after 
10 years. 
Present diameter breast high 
(inches). 
Diameter, in inches, 
breast high after 
10 years. 
Uncut 
land. 
Culled 
land. 
Uncut 
land. 
Culled 
land. 
6 
6.54 
6.80 
7.80 
9. 56 
10. 60 
10 
11. 18 
11.88 
12.88 
11.40 
12:34 
13.34 
14. 34 
7 
8 
9. 26 
10. 20 
12 
9..... 
13 
