30 
BULLETIN 871, TJ. S. DEPARTMENT OF AGRICULTURE. 
It is not to be expected that the growth, habits of the dry-rot 
fungus would vary to any extent in regions so closely related 
climatically as the intermediate and optimum ranges of incense cedar; 
therefore, it is reasonable to believe that no matter what the classifi- 
cation of the trees on the intermediate area may be in respect to 
dominance and suppression when compared with the volume-growth 
curve for that area, to find the true relation of the dry-rot fungus to 
dominant and suppressed trees it will be necessary to determine the 
classification of each tree by comparison with the volume-growth curve 
for the optimum area. 
This is brought out in Table II, in which the trees from all the areas 
are combined, the dominance or suppression of all the trees being 
determined by comparison with the volume-growth curve for the 
optimum area. Only trees in which the progress of the decay or a 
fire scar did not make it impossible to determine the age at stump 
height are included in this table, This explains the slight dis- 
crepancy between the total number of trees dissected and the total 
number included in this and subsequent tables. 
Table II. — Chill caused by dry-rot found in incense cedars of the combined areas. 
Age class. 
Number of trees 
(basis). 
Average age. 
Cull caused by dry-rot 
(percentage of the 
total volume). 
Dominant. 
Suppressed. 
Dominant. 
Suppressed. 
Dominant. Suppressed. 
1 

8 
60 
66 
42 
34 
1 
43 
125 
218 
191 
84 
40 
57 
105 
140 
179 
222 
258 
294 
332 
368 
436 

41 to SO years 
81 to 120 years 
121 to 160 years 
161to200vear* 
201 to 240 year- 
74 
105 
142 
ISO 
223 
265 
301 
341 
372 
1 
4 2 
4 4 
7 12 
19 26 
241 to 280 years 
15 1 79 
7 i 42 
3 16 
2 2 
2 
52 40 
2S1 to 3 9 years 
68 60 
321 to 360 years 
68 66 
361 to 400 years 
83 68 
401 to 440 rear 5 
5 
Combined 
237 S03 
166 
173 
16 20 
Iii Table II the dry-rot percentage in the age class 161 to 200 
years, for example, is figured on the total volume of all the dominant 
trees both sound and decayed in that age class and not on the total 
volume of both dominant and suppressed trees. This is the method 
used throughout the table. 
It will be noticed that the number of trees (basis) in the suppressed 
class far exceeds the dominant, this being a direct result of the 
influence of regional suppression on the trees of the intermediate area. 
The columns of greatest interest are the last two, in which the 
dry-rot percentages of the dominant and suppressed trees in the 
different age classes are directly comparable. By dry-rot percentage 
is meant the percentage of cull caused by the decay resulting from 
