Experimental Procedure 



From February through September 1969, more than 100 foliage collections of big 

 sagebrush were taken from widely scattered areas in Utah, Nevada, Idaho, Wyoming, and 

 Colorado. We obtained these from a wide variety of sites so that the collections would 

 be fairly representative of the species distribution. In addition to using them in the 

 chemical analyses described below, the degree of grazing by big game was determined to 

 discover if palatability , or preference, was associated with geographical source or 

 ecotype. Observations were made at locations where grazing pressure had not been severe 

 enough to force utilization of unpalatable plants. Generally, the degree of grazing 

 was determined in January, but some observations were made in February and March, and 

 a few were made in April. Palatability was given a low rating where less than 15 

 percent of the current growth was removed, medium where utilization was 15 to 40 per- 

 cent, and high where utilization was more than 40 percent. The degree of herbage remov- 

 al was determined by the technique described by Pechanec and Pickford (1937) . 



Since we were aware that palatability may be affected by soil or other environ- 

 mental factors, about 100 plants under 2 years old were collected from each of ten 

 geographical sources of big sagebrush. These plants (totaling about 1,000) were trans- 

 planted from their natural sites to comparable randomized rows spaced 3 feet apart on 

 State Fish and Game land located on deer winter range near Price, Utah. Transplanting 

 was done in April and early May of 1968. Plants from three of these sources had been 

 observed to be especially palatable to deer; plants from seven sources had been cate- 

 gorized as unpalatable while growing on their natural sites. The degree of grazing on 

 these transplanted rows was determined in January 1969 and 1970 by the same technique 

 described above. 



Foliage collections from plants of the more than 100 sources were placed in brown 

 paper bags and dried in the absence of light. Then, by use of a mortar and pestle, 

 0.5 grams of the dried leaves were pulverized and placed in brown 30 ml. bottles, and 

 7.0 ml. of absolute methanol was added to extract phenolic constituents. After 24 hours 

 at room temperature, the extract was decanted and concentrated by evaporation to 2.0 ml. 

 Twenty-five ul of this extract was applied to duplicate 9-inch squares of Whatman No. 3 

 MM chromatographic grade filter paper in two dimensions. The solvent system for the 

 first dimension was n-butanol, acetone, water (4:1:3) and for the second dimension, 

 acetic acid, water (15:85). Chromatograms were viewed under longwave ultraviolet light 

 before and after exposure to ammonia fumes and in daylight following the application of 

 ammonia in order to note the appearance and color changes of the resulting spots. Each 

 spot was given an arbitrary number for identification purposes and the value of each 

 was computed for both directions of the finished chromatogram. 



Distance of spot from starting point 



f Distance of solvent front from starting point 



The R^ value of a given spot is then expressed as : 



R~ = R,. (first dimension)/R 4 -(second dimension) 



2 



