Trey divided plant ccrmunities elevationally intX) t;'« groups: plains 

 ccmmunities occxirring primarily belcw 14CX) m, and nx^ntane ccmrnunities 

 primarily above 1400 n. Figure 2 profiles vegetation ccmmunities 

 across the montane regicn of East Butte. 



PLAI^S CaT-7JNITIE3 



Agricultural land . Vost of the flat, arid prairie surrounding the 

 Hills has been altered by agriculture. Little native prairie, 

 prcbably formerly dominated by western wheatgrass, needle-and- 

 thread and blue grama, new rerrains. 



Foothills prairie . The higher grasslands surroundirg the Hills 

 (about 1100 to 1500 m) are similar to the foothills prairie 

 described by Kuchler (1964), normally supporting stands dcminated 

 by wheatgrasses, fescues and needle- and- thread . 



Riparian shrubteiy . Edges of intermittent prairie streams are 

 lined with shrub ccrrmunities generally dcminated by serviceberry, 

 havrthom ard chrf^echerry. Scattered stands of boxelder are 

 present alcng seme drainage bottcms. 



Riparian forest . A deciduous forest associaticn dcminated by 

 black cottcnwood and plains cottonwood extends into the mcntane 

 region of the Hills, reaching elevations up to 1500 m alo-g Breed 



13 



