Project Area and Sampling Sites 



The project area is located within Level IV ecoregion 15i (Salish Mountains), which is 

 part of the Northern Rockies Ecoregion in Flathead County, Montana (Woods et al. 1999). The 

 Salish Mountains are forested and underlain by Precambrian Belt rocks. Its crests are mantled 

 with \olcanic ash. rarely exceed an elevation of 7,000 feet, and lack the alpine zones that occur 

 in higher mountains. Average precipitation is about 20 to 50 inches per year. The region was 

 glaciated by the Cordilleran ice sheet, which modified physiography and deposited till. Climax 

 vegetation consists of Douglas-fir, subalpine fir, grand fir, and Engelmann spruce forests. The 

 main land uses are logging, recreation, watershed, and wildlife habitat. 



Periphyton samples were collected at three sites on Logan Creek upstream from Tally 

 Lake (Table 1). Logan Creek is a tributary of the Sullwater River (USGS HUC 17010210), 

 which is a tributar>- of the Flathead River. Logan Creek is classified B-1 in the Montana Surface 

 Water Quality Standards. 



Methods 



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 importance of those 

 substrates at each 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 (IKI) solution. 



The samples were examined to estimate the relative abundance of cells 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 Smith (1950), Prescott (1962, 1978), John et al. 

 (2002), and Wehr and Sheath (2003). These books also served as references on the ecology of 

 the soft algae, along with Palmer (1969, 1977). 



