varied among years and sites. At five sites 

 mean number of fruits per plant varied from 

 9.4 to 22.0 in 1990-91 (Walsh 1992). 



Seeds from both Charleys Gulch and Canyon 

 Creek demonstrated 85-90% germination in 

 warm/light conditions without stratification. 

 Seeds from Charleys Gulch also germinated 

 readily in cold/dark conditions, but these 

 same conditions induced dormancy in seeds 

 from Canyon Creek (Lesica and Shelly 1994) . 

 These results suggest that at some sites 

 Arabis fecunda has only a transient seed 

 bank, while at others there may be a long- 

 term seed bank. 



Seeds are small and are shed as the fruit 

 splits open on the flower stem. They are 

 probably projected from the parent plant by 

 wind shaking the stems. Biological vectors 

 are unknown. 



DEMOGRAPHY: Arabis fecunda is a relatively 

 short-lived perennial; only ca. half of the 

 plants that establish live for more than two 

 years, and only ca . one-third live for four 

 years or more (Lesica and Shelly 1994) . 

 Annual recruitment is generally high; the 

 ratio of new recruits to survivors varied 

 from 0.09 to 2.06 with means for 1989-9 J 

 between 0.31 and 0.95. Mortality of new 

 recruits is also high; in 1991-93, it varied 

 from ca. 20-50% (Lesica and Shelly 1994) . 

 Fecundity is generally high; reproductive A^ 

 fecunda plants produced an average of 10-15 

 fruits, and the number of seeds per fruit 

 averaged 31-34. Thus, reproductive plants 

 produced an average of 340-500 seeds per year 

 (Lesica and Shelly 1994). Plants that bolted 

 produced ca. 2.5 times as many seeds per year 

 as axillary flowering plants but have much 

 higher mortality (Lesica and Shelly 1994) . 



There is great variation in life history 

 traits among Arabis fecunda populations. 

 The Arabis fecunda population at Charleys 

 Gulch (E0#001) had a lower recruitment rate 

 but higher overall as well as new recruit 

 survivorship. On average, plants grew more 

 slowly, were older at first reproduction, and 

 had lower annual fecundity as a result of 

 producing fewer seeds per fruit. The Canyon 



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