sparse compared to surrounding grasslands and woodlands. Cryptogamic soil 

 crusts are coiranon at Charleys Gulch and Lime Gulch (Lesica and Shelly 1992a) . 

 Soils at Charleys Gulch have a lighter albedo than those at the Beaverhead 

 County sites. 



Field methods 



In 1987 we established two permanent transects, one of 5 and one of 12 

 contiguous 1-m- plots at Charleys Gulch. In 1989 we established two permanent 

 transects of 12 contiguous 1-m^ plots each at both Lime Gulch and Vipond Park. 

 Transects were located to be representative of the populations a whole. We 

 censused Arabis fecunda in 1988-93 at all three sites. Sampling was conducted 

 in late May at Charleys Gulch, mid-June at Lime Gulch and late June or early 

 July at Vipond Park. We chose these times because A_^ fecunda fruits were 

 mature or nearly so, but dispersal had not yet occurred. Plants smaller than 

 0.5 cm in diameter were not recorded because they could not be reliably 

 distinguished from other species. 



Individual A^ fecunda plants were mapped and recorded following methods 

 outlined in Lesica (1987) and using the following life history stage 

 classification system: 



Small (S) = single vegetative rosette < 2 cm in diameter 

 Juvenile (J) = single vegetative rosette > 2 cm in diameter 

 Multiple-rosette (M) = multiple vegetative rosettes 

 Reproductive (R) = plants producing 1-many inflorescences 



In addition, for each reproductive plant we recorded the number of 

 inflorescences and the number of fruits matured. We recorded which plants 

 bolted in 1990-93. 



