monospecific dominant Pascopyrum smithii (coverages 

 generally in excess of 60 %) and low forh diversity. 

 Within the RNA, almost all of these habitats have 

 been either seeded to, or invaded by, Agropyron 

 cristatum (crested wheatgrass) and Bromus inermis 

 (smooth brome) though Pascopyrum smithii has often 

 maintained dominance or co-dominance. [No Plot] 



Symphoricarpos occidentalis Shrubland 



[SYMOCC] 



western snowberry shrubland 



This is a common Northern Great Plains type of 

 subirrigated settings or those receiving overland flow, 

 draws and swales, positions that on the RNA are 

 merely mesic uplands and not wetlands or riparian 

 habitat. The RNA examples of this type are small 

 inclusions in more extensive types and are in relatively 

 good condition with the density of western snowberry 

 (Symphoricarpos occidentalis) sufficient to exclude most 

 other species except for the rhizomatous grasses like 

 western wheatgrass (Pascopyrum smithii), smooth brome 

 (Bromus inermis, and Kentucky bluegrass (Poa 

 pratensis). [No Plot] 



OVERALL BIODIVERSITY SIGNIFICANCE: 

 Tepee Hills has the most intact vegetation overall 

 among the Medicine Lake Refuge's established RNAs, 

 a slice of Great Plains landscape. Perhaps the most 

 significant ecological feature captured by this RNA is 

 the Stipa curtiseta - Elymus lariceolatus plant association, 

 a relatively high quality example of what is considered 

 as an important vegetation type of the Canadian 

 glaciated plains. There are no other protected examples 

 of this community documented within the state. 



OTHER VALUES: 



Tepee Hills has archeological values, featuring a 

 historic Native American encampment, recognized on 

 the National Registry of Historic Places. 



LAND USE: 



Tlie area was grazed prior to RNA establishment. It has 

 light non-motorized recreational use. It is bordered by a 

 crested wheatgrass planting on the west that may 

 extend within RNA boundaries. 



MANAGEMENT COMMENTS: 



Tepee Hills is a relatively small area, surrounded mainly 

 by agricultural lands and man-made features that can 

 he expected to provide a continuous threat through 

 weed introductions and simple fragmentation of 

 populations and habitat. It is situated between a CRP 



planting of crested wheatgrass (Agropyron cristatum) to 

 the north and a weedy roadside right-of-way to the 

 south. A large area of smooth brome (Bromis ir^ermis) 

 has become established on the western end of the 

 ridgetop. Planted windbreak species within the RNA 

 include Siberian pea-shrub (Caragana arborescens) and 

 green ash (Fraxinus pennsylvanica) . It was burned in the 

 spring of 1994 (Rabenberg pers. commun.) 



52 



