256 



G. A. PEARSON 



TABLE 1 

 Results of planting 



CHARACTEH OF PLOT 



PLOT 



NUMBER 

 PLANTED 



PER CENT OP PLANTS IN OOOD CONDITION 



October, 

 1911 



August, 

 1912 



October, 

 1912 



August, 

 1913 



Open. . 

 Aspen. 



1912 Planting 



Open. 



Average. 

 Aspen 



Average. 



63.0 

 60.0 



61.5 



70.0 



78.0 



74.0 



1913 Planting 



Open. 



Average. 

 Aspen 



Average. 



78.0 

 84.0 



81 



92.0 

 83.0 



87.5 



usually the entire plant dies, although plants which begin to 

 fail toward the close of the dry period frequently revive after the 

 beginning of the summer rains. 



The relation with respect to soil moisture varies in different 

 years (table 2). The plots planted in 1911 show the same average 

 moisture content in the open as under the aspen. In 1912 the rela- 

 tion is variable, with a margin in favor of the aspen-covered plots 

 during the months of May and June and September which are 

 typical of the two dry periods of the growing season. The 1913 

 plots, however, show a noticeably higher moisture content in 



