Another failing of many competition experiments is their 

 short duration. Competition may be occurring, but relatively 

 long periods of time may be necessary to observe it (MacArthur 

 1972) . Furthermore, the effects of competition may change with 

 time, thus a short-duration study can yield misleading results 

 with regard to long-term community dynamics (Tilman 1988) . 



Arabis fecunda Rollins is a short-lived, rosette- and 

 taproot-forming perennial in the Mustard Family (Brassicaceae) . 

 This recently described species (Rollins 1984) is endemic to 

 highly calcareous soils in the foothills of the Sapphire Range in 

 Ravalli County and in the Pioneer Range in Beaverhead and Silver 

 Bow counties in southwest Montana (Lesica 1985, Schassberger 

 1988) . Plants bloom in early spring and disperse seed during 

 early to mid-summer. The small seeds germinate readily without 

 stratification (Lesica, unpublished data) . Presumably most 

 germination occurs following late summer and autumn rains, but a 

 second bout of germination may occur in the spring. Mortality of 

 seedlings and first year plants is high (Lesica and Shelly, 

 unpublished data) . Plants generally grow for at least one year 

 before blooming and then produce one or more inflorescences with 

 3-many flowers. Individuals may branch at the root crown to form 

 multi-rosette plants at any time during the life cycle. Rosettes 

 are generally 1-4 cm in diameter. 



