analysis shows that growth and survival of the non-reproductive 

 plants is the most consistently important life history parameter 

 contributing to population growth and stability. Recruitment 

 from seed was important in less than half the years, and was not 

 of overriding importance in any year. Greater importance for 

 growth and survival has been observed for many long-lived 

 perennial species (Silvertown et al. 1993) . 



Significant predation of Astragalus scaphoides 

 inflorescences and/or seeds occurred in every year when flowering 

 was at all abundant. However, this predation affected mainly 

 seed production and recruitment and probably had little effect on 

 growth and survival of plants. Since recruitment is only 

 important to population growth in some years and never accounted 

 for more than 40% of X, inflorescence and seed predation should 

 not have a critical impact on A_^ scaphoides populations. Even 

 heavy predation should be significant only if it is consistent. 

 These theoretical predictions are supported by the fact that 

 predation was common during the course of the study and was 

 severe in some years, and yet both sample populations expanded. 



Livestock are attracted to concentrations of flowering 

 Astragalus scaphoides in the spring and can severely suppress 

 reproduction. At Sheep Corral Gulch, appreciable predation of 

 inflorescences by livestock occurred in 1993 and to some extent 

 in 1989. In 1986 and 1991 A^ scaphoides flowered heavily, but 

 livestock were not present in the spring due to a rotation 

 grazing system. It would appear that livestock grazing will not 

 adversely affect A^ scaphoides populations unless it is 

 consistent and long-term. Consequently rotation grazing systems 

 should be employed where populations of this rare plant occur. 



ACKNOWLEDGEMENTS 



I am grateful to Joe Elliott and Lou Hagener for help in the 

 field. 



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