significant source of variation in fecundity (ANOVA; N=1461, 

 F=25.7, P<0.001). None of the sites were significantly different 

 from any others as determined by contrast test after the ANOVA 

 (P>0.15), but Birch Creek and Vipond Park together, the two sites 

 with the greatest overall fecundity, were significantly higher 

 than Charleys Gulch and Lime Gulch (P<0.001). 



The number of seeds per fruit varied from 5 to 56, and means 

 varied from 26 (SE=2.0) at vipond Park in 1990 to 38 (SE=1.1) at 

 Birch Creek in 1987 (Table 2) . The number of seeds per fruit 

 differed significantly among years (ANOVA; N=325, F=9.3, P<0,001) 

 but did not differ significantly among sites (F=1.4, P=0.25). 



Weather and life history 



Mortality was negatively associated (N=15, r=0.6l) and 

 recruitment was positively associated (N=15, r=0.48) with winter 

 precipitation. Higher fecundity (fruits/plant) was associated 

 with warmer fall and winter temperatures and higher fall 

 precipitation (multiple regression r=0.78, N=19) . 



Overall, there were few consistent relationships between 

 weather and Arabis fecunda demographic parameters. The behavior 

 of populations at different sites was highly idiosyncratic. For 

 instance, mortality was well below normal at Birch Creek, Lime 

 Gulch and Vipond Park in 1989-90 but was above average at 

 Charleys Gulch. Recruitment was higher than average at Charleys 

 Gulch and Lime Gulch in 1990-91 but was below normal at Birch 

 Creek and Vipond Park. Fecundity was high at Birch Creek and 

 Charleys Gulch in 1989 but was below average at Lime Gulch and 

 Vipond Park. 



DISCUSSION 



Arabis fecunda appears to have two distinctive life'-history 

 strategies. Populations at Charleys Gulch and Lime Gulch showed 

 similar demographic responses and had higher survivorship, lower 

 mortality, lower recruitment rates and lower fecundity compared 

 to populations at Birch Creek or Vipond Park. Arabis fecunda 

 populations at Charleys Gulch and Lime Gulch had similar 

 demography and were less variable in size and growth rate as well 

 as demonstrating less variation in recruitment and mortality 

 rates than those at Birch Creek or Vipond Park. Populations at 

 Birch Creek and Vipond Park have a high variation strategy, while 

 those at Charleys Gulch and Lime Gulch have a more stable state 

 strategy. 



Intraspecif ic differences in demography can be the result of 

 genetic differentiation among populations and/or phenotypic 

 plasticity. The existence of intraspecif ic ecotypes that differ 



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