6 BULLETIN 871, IT. S. DEPARTMENT OF AGRICULTURE. 
Douglas fir predominates, the two pines take second place, and vice 
versa. Third in order comes incense cedar, while sugar pine (Pinus 
lambertiana) and white fir (Abies concolor) are but lightly represented. 
In the more dense stand on the lower slopes and in the draws 
incense cedar forms a distinct understory, overtopped by all the other 
species; it is in such localities that the cedar shows every indication 
of slow growth and strong suppression. On the higher slopes and 
along the ridges, where the stand is more open, the cedar in individual 
cases often assumes a better position in the stand, and all the trees of 
this species, with few exceptions, appear to be more thrifty and to 
have made a more rapid growth. Badly suppressed trees are rare. 
The three areas selected to represent the optimum range are on 
the Stanislaus National Forest in the southern Sierra Nevada Moun- 
tains. One of these is at Strawberry, at an altitude of 5,300 to 5,600 
feet; a second at Cow Creek, about 5 miles north and east of the 
first and at about the same elevation; and the third at Crockers 
Station, about 30 miles to the south and a little east of the Straw- 
berry area and at an altitude of about 4,500 feet. Since the areas 
are so nearly alike, a composite description will suffice. 
The soil is a rather deep, loose, decomposed granite, with many 
large granite bowlders. It is normally somewhat dry. 
The virgin uneven-aged overmature stand is rather open and is 
composed of sugar pine, western yellow pine, Jeffrey pine, white fir, 
incense cedar, and Douglas fir. Normally the pines predominate, 
with white fir or incense cedar next in order, Douglas fir being found 
sparingly only on the Crocker area. Incense cedar is represented 
by trees of all ages, and on the whole appears very thrifty. There 
are many individuals of large size, comparatively young. The cedar 
here is far from forming such a distinct understor}^ as on the Sloat 
area, so the stand has made a much more rapid growth. 
NOTES ON INDIVIDUAL TREES. 
After the general notes were completed on an area, work was 
commenced on individual trees. Trees of all ages and conditions 
must be cut for a study of this kind, the primary purpose being to 
determine the age of the stand at which dry-rot becomes extensive. 
Observations on logging operations and the results of Meinecke's 
preliminary study had shown that trees between 100 and 240 years 
old would yield the essential data on this point, and it was within 
these age limits that the investigation was concentrated, but the 
lower and higher ages were not neglected by any means. This 
resulted in clear cutting within the ages mentioned, except that those 
trees in Which it was plainly apparent an accurate age count could 
not be made were left standing, while only a portion of the trees in 
the stand above and below these ages were cut. Thus, since a given 
