18 
BULLETIN 1176, U. S. DEPARTMENT OF AGRICULTURE. 
abundant seed crop ripened during the season of felling, stirring up 
the soil by logging, a series of favorable seasons Allowing germina- 
tion, and the miraculous escape from slash fires. (PL III.) Ob- 
viously such stands can not be counted on regularly in practice. 
The reasons for the failure to secure at will abundant reproduction 
of desirable species are not so evident. In most cases at the time of 
cutting advance growth is present in openings made by lire or insects, 
and even directly under the more open, older stands. Investigation 
shows that as a rule there is a great range in age of these seedlings, or 
that they germinated abundantly during certain widely separated 
years — that is, advance growth originated either by a long, gradual 
process or by rare combinations of favorable circumstances. 
The slow progress of restocking is brought out in tabulation (Table 
13) of selected typical data, which shows the differences between 
the number of seedlings present at two examinations of the same 
area made at intervals of from 4 to 10 years. Advance growth or 
reproduction which had become established before logging is in- 
cluded. Examinations at intermediate periods have shown that some 
seedlings start practically every year, but deaths due to drought, 
rodents, and unknown causes almost or more than offset the number 
of new trees. The conspicuous decrease in number on the Feather 
River plots is due to the fact that the 1913 examination was made 
prior to logging and brush burning and included seedlings of the 
current year's germination, in which mortality is always high, a 
condition not true of the other plots. Certain changes in methods 
make comparison with the earlier examinations in most cases rather 
difficult, and they have been omitted, but the general trend or results 
would be the same. 
Table 13. — Progress of reproduction, <il1 species. 
Plot and date. 
Seed- 
lings per 
acre. 
Per cent 
of origi- 
nal. 
Plot and date. 
. Seed- 
lings per 
acre. 
Per cent 
of origi- 
nal. 
Shasta: 
1915 
4,5:54 
4, 165 
540 
493 
1,270 
1,352 
100.0 
91.9 
100.0 
91.3 
100.0 
108.5 
Feather River 1 to 8: 
1913 
25,366 
5, 464 
9,680 
8,544 
1,690 
1,690 
100. 
1920. 
1919 
Sierra: 
1916 
1920 
Sequoia-1 : 
1916 
1920 
21.5 
Tahoe: 
1916. 
100.0 
1920. 
88. :; 
Plumas: 
1910 
100. 
L920 
100.0 
It was stated above that the stand of seedlings on most of the 
plots was deficient. It might be assumed from Table 13, which shows 
totals of 4,000 to 10,000 seedlings per acre on some of the plots, that 
this was not true. It should be explained, however, that from 35 to 
67 per cent of the reproduction is incense cedar, over half of which 
consists of dense patches of small seedlings less than 6 inches high. 
Only a very small portion of this will ever reach large size. 
The reasons for this slow progress in restocking will not be dealt 
with at length, because lack of sufficient meteorological, seed crop, 
light intensity, and other data at present restricts the discussion to 
generalities of slight interest. Briefly, there are several outstanding 
