Nov. 15, 1925 
Preliminary Study of Growth of Noble Fir 
931 
Noble fir is less tolerant than either western hemlock or amabilis 
fir, its light requirements being about the same as those of Douglas 
fir. Seedlings are seldom found in the shade of older stands, the 
undergrowth usually consisting of stunted hemlock and amabilis dr. 
Noble fir seed will germinate both upon bare mineral soil and on 
duff, preferably the latter. It requires rather moist soil conditions 
for best results. Reproduction takes place only in openings, such 
as are caused by fire or lumbering. 
Noble fir is probably best adapted to a mixed type of forest where 
it is able to maintain a dominant position in the stand, such as when 
in mixture with Douglas fir and hemlock, or amabilis fir and hem¬ 
lock. Since it does not reproduce itself under shade, clear cutting 
in groups or strips is apparently necessary to obtain satisfactory 
natural reproduction. In the present mature stands, in order to 
accomplish natural restocking, cutting should take place in the spring 
following a good seed year. This will insure a crop of seed on the 
ground which should find favorable conditions for germination after 
the old stand has been cut. Fire should be kept out of the cut-over 
area. On the upper slopes, where for protective reasons clear- 
cutting can not be followed, the selection system is applicable, ia 
which rather heavy cuttings should be made in order to open up the 
stand sufficiently for noble fir to take hold. Due to its superior 
qualities, noble fir should be favored more than any other species, 
with the exception of western white pine, in the upper portions of the 
lower-slope and in the lower portions of the upper-slope type. 
GROWTH 
It is probably in direct competition with a rather intolerant species 
such as Douglas fir that noble fir attains its best growth, both in 
diameter and in height. 
Figure 1 illustrates graphically the diameter growth of noble fir, 
Douglas fir, and western hemlock in a mature stand, where the trees 
of all species averaged about 400 years of age. The results are for 
all the dominant trees on the tract. 
Table I gives the average rate of diameter growth and height growth 
of noble fir in a mixed stand of Douglas fir and western hemlock at 
a elevation of from 3,000 to 3,500 feet on the west slope of the 
Cascade Mountains in northern Oregon. 
Table I .—Average rate of diameter and height growth of noble fir , in mixed stand, 
on the west slope of Larch Mountain, Or eg. 
Age 
Average 
diameter 
at breast 
height 
Average 
annual 
diameter 
growth 
in each 
decade 
Average 
total 
height 
Average 
annual 
height 
growth 
in each 
decade 
Age 
Average 
diameter 
at breast 
height 
Average 
annual 
diameter 
growth 
in each 
decade 
Average 
total 
height 
Average 
annual 
height 
growth 
in each 
decade 
Years 
10 
Inches 
0.0 
Inches 
Feet 
4.0 
Feet 
Years 
130_ 
Inches 
25.0 
Inches 
0.14 
Feet 
116.1 
Feet 
0.51 
20 . 
3.1 
0.31 
12.0 
0.80 
140_ 
26.3 
.13 
120.9 
.48 
30 
6.0 
.39 
23.5 
1.15 
150.. 
27.6 
.13 
125.4 
.45 
40.. 
8.7 
.27 
38.4 
1.49 
160. 
28.8 
.12 
129.7 
.43 
50 
11.1 
.24 
53.0 
1. 46 
170_ 
30.0 
.12 
133.8 
.41 
60 
13.3 
.22 
65.5 
1. 25 
180. 
31.1 
.11 
137.8 
.40 
70_ 
15.3 
.20 
76.2 
1. 07 
190.. 
32.2 
.11 
141.7 
.39 
80. 
17.1 
. 18 
85.2 
.90 
200 _ 
33.2 
.10 
145.5 
.38 
90 _ 
18.8 
. 17 
92.8 
. 76 
250. 
37.9 
.09 
162.2 
.31 
100 
20.5 
. 17 
99.5 
.67 
300. 
42.1 
.08 
175.8 
.26 
110_ 
22.1 
. 16 
105.5 
.60 
350. 
45.9 
.07 
187.3 
.21 
120 _ 
23.6 
. 15 
111.0 
.55 
400.. 
49.4 
.07 
196.3 
.16 
