c 



along Box Elder Creek is dominated by graminoids and introduced 

 herbaceous species. The sparse shrub layer is dominated by 

 western snowberry, sandbar willow, peachleaf willow, and box 

 elder (RWRP Website) . The main land use is livestock grazing. 



Elevations at the sampling sites range from about 2,940 feet 

 at the upper site (Reach 022) to 2,860 feet at the lowest site 

 (Reach 001) . Box Elder Creek is an intermittent "pooled channel" 

 stream with a silty bottom (Amy Chadwick, RWRP, personal 

 communication) . It is classified C-3 in the Montana Surface 

 Water Quality Standards. 



METHODS 



Periphyton samples were collected from pool edges at 8 sites 

 in early August 1999 (Table 1) . Three replicate samples were 

 collected at one of these sites (Reach 003) . Reach 022 was 

 considered to be a "properly functioning" reference reach from 

 the standpoint of riparian habitat. The other reaches were rated 

 "functional at risk" (Amy Chadwick, RWRP, pers . comm. ) . 



Periphyton samples were collected following standard 

 operating procedures of the MDEQ Planning, Prevention, and 

 Assistance Division. Using appropriate tools, microalgae were 

 scraped, brushed, or sucked from natural substrates in proportion 

 to the rank of those substrates at the study site. Macroalgae 

 were picked by hand in proportion to their abundance at the site. 

 All collections of microalgae and macroalgae were pooled into a 

 common container and preserved with Lugol ' s solution. 



Samples were examined to estimate the relative abundance and 

 rank by biovolume of diatoms and genera of soft (non-diatom) 

 algae according to the method described in Bahls (1993) . Soft 

 algae were identified using Prescott (1978), Smith (1950), and 





