60 BULLETIN 55, U. S. DEPARTMENT OF AGRICULTURE . 
In New Hampshire, measurements of over 2,000 acres gave an 
average yield of 482 board feet for balsam and 1,772 board feet for 
spruce (New Hampshire rule), or nearly 0.8 of a cord of balsam fir 
per acre, forming about 27 per cent of the entire spruce yield. 
(Table 50.) 
Table 50. — Average yield of balsam fir over large areas in Grafton County, N. H. 
[New Hampshire log rule.] 
Area (acres). 
Total yield. 
Spruce. 
Balsam. 
Average yield per acre. 
Spruce. 
Balsam. 
107 
112 
115 
135 
141 
190 
574 
259 
446 
154 
Total (2,233) 
Board feet. 
124, 976 
273,840 
94, 645 
170,235 
38,211 
651, 510 
1,402,856 
437, 192 
617,264 
146, 146 
Board feet. 
63,879 
93, 520 
10,925 
14, 715 
846 
67,260 
392,616 
172,494 
174, 386 
84,700 
Board feet. 
1,168 
2,445 
823 
1,261 
271 
3,429 
2,444 
1,688 
1,384 
949 
Board feet. 
835 
95 
109 
6 
354 
684 
550 
3,956,875 
1,075,341 
1,772 
482 
INCREMENT. 
The sample plots in New York and Maine (Tables 46 and 47) 
showed that mature stands of balsam fir produce annually from 
one-sixth to one- third of a cord of wood per acre. At such a rate 
the poorest land produces 10 cords per acre in 60 years, and the better 
land 10 cords of pulpwood every 30 years. This annual increment is 
very low as compared with the yields obtainable under forest manage- 
ment. The increment should be at least two-thirds of a cord, or 
possibly 1 cord a year. 
MANAGEMENT. 
EFFECT OF PAST CUTTING. 
Balsam fir is so closely associated with spruce wherever it occurs 
that it is impossible to outline a system of management for one 
species that will not at the same time affect the other. Both species 
are almost constantly contesting for the occupancy of the ground. 
If left to themselves the greater tolerance and more persistent growth 
of spruce would undoubtedly in the long run secure for it the pre- 
dominance in the present forests as they formerly did in the virgin 
stands, before the interference of man. Lumbering, however, has 
turned the scale of the struggle between the different species in 
favor of trees of smaller commercial importance. Thus, white pine, 
the most valuable species of the northeastern forests, was taken 
first, with the result that it was unable to hold its own against its 
competitors. Then came the turn of spruce. The latter, in many 
