30 



DISCUSSION 



Recommendations for the BLM status of the seven species of 

 special concern found in the study area are summarized in Table 

 1. In most cases, no change is recommended in the currently 

 proposed status (USDI Bureau of Land Management 1993), but 

 sensitive status is recommended for Astragalus terminalis rather 

 than the proposed watch status, and watch status is recommended 

 for Sphaeromeria argentea, for which no special status has been 

 proposed. The recommended sensitive species are extremely rare 

 in Montana and/or are demonstrably threatened under current land 

 uses. Watch status is recommended for species which are rare but 

 which do not seem to be threatened at the present; they should be 

 considered if changes in management are proposed (e.g. new roads 

 and mines) in the areas where they occur. No special status is 

 recommended for species which are relatively widespread in 

 Montana and which do not seem to be threatened by current or 

 foreseen land uses. 



Table 2. Current and recommended BLM status for Montana plant 

 species of special concern found in the Horse Prairie Creek study 

 area. 



The most significant threat to sensitive plants on BLM land 

 in the Horse Prairie Creek drainage is cattle grazing. Grazing 

 has been documented to impact populations of Astragalus 

 scaphoides (Lesica and Elliot 1987) and Penstemon lemhiensis 

 (Shelly 1990) and most populations of these species are in 

 primary range within allotments. The levels of grazing in the 

 Horse Prairie area are often very high, but populations of 

 sensitive plants were found only in less heavily grazed habitats, 



