22 
BULLETIN 
DEPARTMENT* OF AGRICULTURE. 
serious damage by sheep and cattle, (1) the rate of growth of the 
reproduction and the age at which the major portion of the stand is 
exempt from serious browsing, and (2) the density of the stand that 
may be expected, and accordingly the extent of thinning, if any, 
30,000 
80,000 
% 70,000 
<^ 60,000 
8 50,000 
j. 40,000 
^ 30,000 
^ 20,000 
"§ 10,000 
k 
JZ 
______ 
1- ? 
~" 
sS 
/ /-- " ~~~ 
/• 
^^^^ 
1 
\ 
-- / 
/ 
/ 
/ 
/ 
/ 
/ 
/ 
^. 
i- 
I ! 
^-^ 
\ 
^ 
~~h 
i i 
■"»— 
/ 1 
i 
I 
/ 
2 
/ 
t 
/ 
i 
Fall Spring 
1912 19/3 
Fall 
1913 
Spring Fall Spring Fall Spring Fall 
1914 1914 1915 1915 .191$ 1916 
Sprinq Cuff mi 
>prtn S 
Si 
Cuffim 
Fa If Cuffim 
Fig. 7.— Number of sprouts and average height growth according to season of cutting. 
that may be permitted by browsing and that will leave enough 
reproduction to secure the number of trees which the lands will well 
support. 
To determine the sprouting capacity of aspen and the corresponding 
vigor and rate of growth of the resulting sprouts when the lands are 
clear-cut in different seasons, the timber was removed on three plots 
of even-aged aspen, each one-half acre in size. One of the plots was 
clear-cut in the fall of 1912, another early in the spring of 1913, and 
the third in midsummer 1913. In Table 10 is summarized the number 
of living sprouts per acre on these plots and the height growth per 
season according to the time of cutting. To facilitate comparison of 
results the data are assembled graphically in figure 7. 
