We are confident that differences in palatability exist within groups I and II, but our 

 observations have not yet been intensive or refined enough to detect this and correlate 

 it definitely with chromatographic analyses. 



Three of the ten collections planted near Price chromatographed as group I. By 

 mid- January in both 1969 and 1970, all of these were grazed by deer to an average of 

 about 60 percent. None of the big sagebrush plants were grazed less than 40 percent; 

 and on several of the plants, grazing was in excess of 80 percent. In contrast, of the 

 seven collections chromatographed as group II, none were grazed more than 40 percent, 

 and most were grazed less than 5 percent. 



All collections from individual A. tridentata plants or populations on winter 

 ranges which had been grazed in excess of 50 percent invariably chromatographed as 

 group I except for the single exception represented by a collection from Utah County 

 (Hobble Creek trial site) and involving some big sagebrush transplants. Moreover, all 

 collections from plants or populations observed to be relatively unpalatable on the 

 open range, chromatographed as group II. This was especially noticeable in the area 

 from which collections of subgroups Id and I la were taken in northwestern Nevada where 

 these two subgroups grow in an intermixed population on a foothill winter range (fig. 8). 

 Subgroup Id on this same range was palatable to the cattle that graze on the area, but 

 I la was unpalatable and grazed very little. By March 15, 1968, subgroup Id on this 

 range had been grazed slightly in excess of 60 percent, and grazing on Ila was less 

 than 15 percent. The partiality for Id was also exhibited by sheep and deer in that 

 area. The difference between subgroups Id and Ila was also evident on the transplanted 

 areas near Price, Utah. A similar selectivity was also noted where subgroups la and lb 

 intermix with lib in Ephraim Canyon. Under these intermix conditions, la and lb were 

 grazed in excess of 70 percent by late January of 1969 and 1970, but none of the plants 

 in subgroup lib were grazed more than 15 percent. 



Id Ila 



Figure 8. — Marked differences were noted in the size of Artemisia tridentata 

 subgroups Id (left) and Ila (right) as a result of cattle grazing in the 

 Jackson mountains in northwestern Nevada. 



7 



