1 



INTRODUCTION 



In order to adequately protect populations of an organism, it 

 is necessary to understand its life history and population dynamics 

 (Massey and Whitson 1980, Sutter 1986, Palmer 1987) . 



Sapphire rockcress ( Arabis fecunda Rollins) is a rosette- 

 forming perennial in the Mustard Family (Brassicaceae) . This 

 recently described species (Rollins 1984) is endemic to highly 

 calcareous, azonal soils in the foothills of the Sapphire Range in 

 Ravalli County and in the Pioneer Range in Beaverhead and Silver 

 Bow counties, Montana (Lesica 1985, Schassberger 1988). Arabis 

 fecunda generally occurs on steep, often eroding slopes with low 

 vascular plant density. In Ravalli County, populations of A. 

 fecunda are thought to be threatened by livestock grazing and 

 encroachment by an aggressive exotic weed, spotted knapweed 

 ( Centaurea maculosa ) (Lesica 1985, Schassberger 1988) . In Silver 

 Bow and Beaverhead counties, populations may be threatened by 

 mining activity and livestock grazing. Arabis fecunda is a 

 candidate for listing as a threatened or endangered species by the 

 U.S. Fish and Wildlife Service (USDI, FWS 1990) and is considered 

 threatened in Montana (Lesica and Shelly 1991) . 



Here we report the results of the first two years of a long- 

 term demographic monitoring study at two sites in the Pioneer Range 

 on Beaverhead National Forest. 



