* 



6 



Shelly, unpublished data) , and crusts may take 14-20 years to 

 develop (Anderson et al. 1982b), it seems likely that plants 

 established in the crust rather than in bare soil before the 

 crust formed. We also recorded size and number of rosette(s), 

 number of inflorescences and number of fruits. For contingency 

 tables, we classified each A^ fecunda plant into one of three 

 life stage classes: 



I. Single sterile rosettes smaller than 2 cm diameter 



II. Single sterile rosettes greater than 2 cm or multiple 

 sterile rosettes 



III. Plants with one or more fruiting inflorescences. 



We chose these classes because they relate to age as well as 

 size. Ongoing demographic monitoring studies at these same three 

 sites showed that in 1990 an average of only 24% of those plants 

 in Class I were more than one year old, while 66% and 89% in 

 Class II and Class III respectively were more than one year old 

 (Lesica and Shelly, unpublished data) . 



We sampled one transect at each of the Ravalli County sites 

 on May 29-30, 1990 and two transects at Lime Gulch, one on June 

 15 and the other on June 28, 1990. 



We compared the distribution of plants among the life stage 

 classes on soil and crust using contingency table analysis. Two- 

 factor analysis of variance (ANOVA) was used to determine the 



