yet well documented. Ongoing studies on the 

 effects of livestock grazing being conducted for 

 BLM and research being conducted by Mitchell-Olds 

 et al. at the University of Montana will shed 

 light on this problem 



Plant species cannot be listed as threatened or 

 endangered in just a portion of their range in the 

 same manner as animals. In lieu of this option, I 

 recommend that Arabis fecunda be retained as a 

 candidate for listing as a threatened or 

 endangered species (C2) . 



2. U.S. FOREST SERVICE: I recommend that Arabis 

 fecunda be retained on the list of sensitive 

 species, even though most populations on land 

 administered by U.S.F.S. appear stable and 

 unthreatened at this time. 



3. U.S. BUREAU OF LAND MANAGEMENT: I recommend 

 that Arabis fecunda be retained on the list of 

 sensitive species, even though most populations on 

 land administered by BLM appear stable and 

 unthreatened at this time. 



CONSERVATION RECOMMENDATIONS: The presence of 

 livestock may be detrimental to Arabis fecunda 

 populations due to both trampling and introduction of 

 exotic weeds. Heavy livestock grazing should be 

 reduced to moderate or light levels in pastures where 

 A. fecunda is present. 



Encroachment by exotic weeds is probably the most 

 significant threat to A^ fecunda populations. Roads 

 are a major source of weed infestations (Sauer 1988, 

 Tyser and Worley 1992) . Road construction or any other 

 major disturbances should be curtailed in areas 

 supporting populations of A^ fecunda. 



Arabis fecunda and Centaurea maculosa may be able to 

 coexist if densities of the latter do not become too 

 great (Lesica and Shelly, submitted) . Although current 

 biological controls for C^ maculosa will not eliminate 

 infestations, they may be able to control them. 

 Biological control agents for C^ maculosa should be 

 introduced at all A^ fecunda sites in Ravalli County 

 (Lesica and Shelly, submitted) . 



The sensitivity of A^ fecunda to various herbicides is 

 not known. Herbicide application should be curtailed 

 in proximity to populations of A^ fecunda . County and 

 state officials should be informed of sensitive sites. 



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