normal range. Kincaid (1988) points out that sodium 

 is often deficient in plants growing in semiarid envi- 

 ronments. Plants in City Creek and Woodbury-Hardy 

 are quite similar in mineral content and nutrients; 

 they differ significantly only in phosphorus and mag- 

 nesium content. Plants in City Creek were higher in 

 phosphorus and those in Woodbury-Hardy were higher 

 in magnesium. Plants in Littlefield had significantly 

 higher values for potassium, copper, sodium, and fat 

 than both the other areas. Plants in Littlefield had 

 significantly higher values for several of the nutri- 

 ents and minerals than those for either City Creek or 

 Woodbury-Hardy but not for both: moisture content, 

 zinc, calcium, magnesium, and sulfur were higher 

 than for City Creek; nitrogen, phosphorus, and man- 

 ganese were higher than for Woodbury-Hardy. When 

 the plant nutrient and mineral contents of the three 

 areas are considered together, they seem similar ex- 

 cept for a trend of Littlefield to be high. Values in 

 Littlefield are not significantly lower than any of the 

 values in City Creek or Woodbury-Hardy and have 

 the lowest mean value only for ADF, in which case 

 the lowest value means the highest quality. 



The results in table 2 are strongly influenced by the 

 contribution of perennial plants, which were more in- 

 tensively sampled. Annual plant values are not signifi- 

 cantly different among areas except for iron (Littlefield 

 plants were significantly higher than Woodbury-Hardy, 

 but not than City Creek, data not shown) and magne- 

 sium (City Creek plants were significantly lower than 

 both (Littlefield and Woodbury-Hardy, data not shown). 

 For perennial plants the differences (table 3) were 

 similar to those for all plants combined (table 2). 



Table 4 compares the data for all life forms of 

 plants (annual grasses, perennial grasses, annual 

 forbs, perennial forbs, shrubs, and succulents). An- 

 nual grasses are low in water, calcium, and magne- 

 sium content and high in nitrogen and copper with 

 respect to the other plant life forms. Perennial grasses 

 are low in nitrogen, phosphorus, potassium, manga- 

 nese, copper, calcium, magnesium, sulfiir, sodium, 

 and fat and high in ADF. Annual forbs are not low 

 in any nutrient or mineral but are high in nitrogen, 

 phosphorus, potassium, iron, and copper. Perennial 

 forbs are low in manganese and high in nitrogen, sul- 

 fur, sodium, and fat. Shrubs are low in iron, manga- 

 nese, and copper and high in nitrogen, potassium, 

 sulfur, sodium, and fat. Succulents are low in nitro- 

 gen, iron, copper, sulfur, sodium, and ADF and high 

 in moisture content, potassium, manganese, calcium, 

 and magnesium. These relative values (high, low, 

 similar) are comparative values and should not be 

 interpreted as high or low values outside the context 

 of this study. 



When the mineral and nutrient contents are com- 

 pared within plant life forms by season (table 5), the 

 patterns are usually similar for all plant life forms. 

 Moisture content decreases seasonally from spring 

 to summer and fall except for succulents, which keep 

 their moisture content relatively stable. Nitrogen, 

 phosphorus, potassium, zinc, and fat also decline sea- 

 sonally following the same general seasonal pattern 

 as moisture content; some of these parameters decline 

 more sharply than others, for example, phosphorus 

 and potassium in perennial forbs, and fat in grasses 

 and perennial forbs. Iron, manganese, copper, calcium. 



Table 3 — Perennial plants: nutrient and mineral values at each study area. Different letters in 

 the same row indicate a significant difference in mean value 



City Creek Woodbury-Hardy Littlefield 



Nutrient 



Units 



(n = 158) 



(n = 167) 



(n = 202) 



Moisture 



Percent 



40.81 



A 



41.61 



A 



49.66 B 



Nitrogen 



Percent 



1.55 



AB 



1.48 



A 



1.73 B 



Phosphorus 



Percent 



0.13 



B 



0.10 



A 



0.13 B 



Potassium 



Percent 



1.29 



A 



1.36 



A 



1.73 B 



Zinc 



ppm 



14.77 



A 



15.84 



AB 



17.93 B 



Iron 



ppm 



243.15 



A 



268.92 



A 



286.61 A 



Manganese 



ppm 



47.51 



A 



38.61 



A 



46.17 A 



Copper 



ppm 



5.77 



AB 



5.63 



A 



6.53 B 



Calcium 



Percent 



1.18 



A 



1.43 



AB 



1.55 B 



Magnesium 



Percent 



0.31 



A 



0.40 



AB 



0.49 B 



Sulfur 



Percent 



0.30 



A 



0.35 



AB 



0.40 B 



Sodium 



Percent 



0.010 



A 



0.010 



A 



0.012 B 



ADF' 



Percent 



36.34 



A 



35.76 



A 



34.04 A 



TNC2 



Percent 



7.37 



A 



7.22 



A 



8.51 A 



Fat3 



Percent 



7.17 



A 



7.48 



A 



8.07 B 



^Acid detergent fiber. 



^Total nonstructural carbohydrates. 



^Sample numbers for fat were 132 (City Creek), 137 (Woodbury-Hardy), and 184 (Littlefield). 



4 



