Figure 2. — Modoa study area, 

 Modoo National Forest, 

 Modoa County, Calif. 



fk ■ /s, ■■■ 



Data obtained annually from the sampled shrubs on each study area were tested 

 for homogeneity of variance by Bartlett's test. When variance was not homogeneous, a 

 t test described by Steel and Torrie (1960) was used to test for significant difference 

 between means. When variance was homogeneous, the t test described by Dixon and Massey 

 (1951) was used. 



Use of the estimated percent of shrub canopy comprised of the two measured 

 branches permitted a calculation of the annual growth for each sample shrub. 



Table 1 . --Descriptive features of three study areas used to assess the effects of 

 topping overmature hitterhrush shrubs 



Study : 

 area : 



Location : 



Elevation 



: Aspect 

 : and 

 : slope 



Soil : 

 parent : 

 material : 



Annual 

 precipitation 



: Mean no. 

 : shrubs 

 : topped 

 : per acre 







Feet 







Inches 





Boise 



18 miles 

 east of 

 Boise, 

 Idaho 



3,400 



SE, 5-30% 



Granite 



18 



155 



Sawtooth 



18 miles 

 south of 

 Twin Falls, 

 Idaho 



5,800 



SE, 0-20% 



Rhyolite 



11 



220 



Modoc 



20 miles 



4,300 



Level 



Basalt 



11 



546 



south of 

 Tule Lake, 

 Calif. 



4 



