4. 



r 



Prairie 



Grassland vegetation dominates the study area, and includes many plant 

 associations. The prevailing upland association includes western 

 wheatgrass and needle-and-thread as co-dominants, both of which are 

 cool-season species. In harsher sites, this grades into associations 

 of needle-and-thread, blue grama and thread-leaved sedge. Searches 

 were made for uncommon prairie habitats that may harbor rare species, 

 so visits were made to sand dunes along the Little Muddy River with 

 their prairie sandreed plant association. BLM lands did not overlap 

 with any of the scattered, discrete dune complexes along the 

 watercourse. 



The more diverse prairie landscape habitats are often pioneer 

 communities on thinsoil settings within othewise continuous prairie 

 vegetation. They are strongly influenced by the parent material and 

 microhabitat features (aspect, slope, topographic position) . They 

 often grade into pioneer shrubland types, mentioned previously. 



Wetland and riparian 



Riparian habitat follows in narrow bands along the largest rivers. 

 Wetland habitat is uncommon apart from wet meadows in floodplains and 

 along outwashes. Surface water in most of these settings is 

 temporary, and the setting may be parched in the latter part of the 

 growing season. Springs and seeps are very rare, particularly the 

 freshwater springs. Beaver pond complexes were found associated with 

 the latter on BLM lands. Many of the wetland and riparian habitats 

 are heavily used by livestock, and have high cover and composition in 

 nonnative species like Kentucky bluegrass, Canada thistle and smooth 

 brome. 



In general, there is relatively uniform habitat over the center of the 

 study area, and relative diverse habitat at the periphery; areas which 

 are least accessibile. 



