hand, livestock are also present at the Ravalli county A_^ fecunda sites, and 

 trampling by livestock or large ungulates can have an adverse effect on adult 

 survival (Lesica and Shelly 1992). Negative impacts resulting from heavy 

 livestock trampling and Centaurea maculosa encroachment taken together may be 

 enough to result in declines of A_^ fecunda populations. 



Anthropogenic global climate change is considered a potential cause of 

 species extinctions in the near future (Dobson et al. 1989, Peters 1988). 

 Populations of Arabis fecunda occur throughout a wide range of elevations and 

 habitats (Schassberger 1988), so it seems unlikely that climatic changes will 

 have adverse effects. 



Acknowledgements 

 Peter Achuff, Anne Garde, Bonnie Heidel, Lisa Roe and Jim Vanderhorst 

 helped conduct field work. We are grateful to George Frost for allowing us to 

 conduct our study on his ranch. This study was funded by Beaverhead National 

 Forest, the U.S. Fish and Wildlife Service and The Nature Conservancy. 



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