I such as Haplopappus acaulis . Artemisia frigida . Phlox muscoides and Sedum lanceolatum . 

 Agropyron spicatum was the only common grass (Table 1). 



Over the two-year period of the study, Arabis fecunda populations at both Lime Gulch 

 and Vipond Park increased in total number of plants as well as number of fruiting plants 

 (Table 2). At Vipond Park I observed predation of A^ fecunda inflorescences in both 1990 

 and 1991. In 1990 the inflorescences were chewed off, probably by grazing ungulates or 

 rodents. In 1991 some plants had wilted inflorescence tops, possibly caused by a stem- 

 mining insect. Damage did not appear extensive in either year. 



Population growth was strongly positive both years at Lime Gulch, but was negative 

 . for the second year at Vipond Park (Table 2). The Vipond Park population showed a strong 



tendency for: (1) a larger proportion of plants to be in the reproductive class, (2) a larger 

 number of fruits per inflorescence, and (3) a larger number of fruits per fruiting plant (Table 

 2). While birth and death rates were relatively constant at Lime Gulch over the two years, 

 the Vipond Park population showed changes of ca. 100% between the two years (Table 2). 

 In general, years that are better for recruitment are also better for survival. The mean 

 number of seeds per fruit was relatively constant among years and between the two sites 

 (Table 2). 



The two populations are at different elevations and in very different topographic 

 positions. The Lime Gulch site is in a sheltered canyon, while the Vipond Park site is 1000 

 ft. higher on a wind-exposed, open, south-facing upper slope. Dominant vegetation and 



